Mirena

Reading time about 17 minutes · Last updated 24 Oct 2026

The largest and longest-lasting hormonal coil – and the only one that also treats heavy periods and serves in hormone therapy. Who it suits, and when Kyleena is the better choice.

Mirena is the largest of the three hormonal coils, carries the most hormone and stays in the longest – and it is the only one licensed not just for contraception but also to treat heavy periods and to serve as the progestogen component of hormone therapy in the menopause. Women who choose it usually do so for one of those reasons. This page explains what it does, who it is meant for and when a smaller coil would be the better choice.

What Mirena is

Mirena is a T-shaped intrauterine system with 52 milligrams of levonorgestrel in its hormone cylinder. Its official name in Austria is now “Mirena 20 micrograms/24 hours intrauterine delivery system” – named after the amount it releases each day, not the reserve it carries. Both descriptions refer to the same product. It measures 32 × 32 millimetres and is inserted with an insertion tube 4.4 millimetres in diameter – a good half millimetre more than Jaydess and Kyleena, and that half millimetre can be felt at insertion.

Hormone release starts at about 20 micrograms a day, falls to around ten after five years and to nine after six. That decline is built in: contraceptive protection remains equally reliable over the whole licensed lifespan. The frame contains barium sulphate so that it can be shown on an X-ray if need be, and the removal threads are brown – details that play no part in everyday life but help when the position is checked.

Three licences, three lifespans

What sets Mirena apart from Jaydess and Kyleena is stated at the very start of the patient information leaflet: it is licensed for three uses, and each has its own lifespan.

For contraception: up to eight years. By then it is removed or replaced at the latest.
For heavy menstrual bleeding: five years – or sooner, if the heavy bleeding returns.
To protect the lining of the uterus during hormone replacement therapy with oestrogen: five years.

So the eight years apply only to contraception. A woman who has Mirena because of heavy periods will discuss a replacement after five years – or as soon as the bleeding becomes heavier again – even though contraceptive protection would run for another three. That is no quibble: the amount of hormone still released in the sixth year is enough to prevent pregnancy, but no longer reliably enough to keep quiet a lining that wants to bleed heavily.

Why Mirena is chosen – and why usually not

Model	Hormone	Lifespan	Insertion tube	Cost per year
Jaydess	13.5 mg	3 years	3.8 mm	€167
Kyleena	19.5 mg	5 years	3.8 mm	€120
Mirena	52 mg	up to 8 years	4.4 mm	€94

The table shows both sides at a glance. In Mirena's favour are the lifespan – eight years instead of five, which is three fewer insertion appointments over a lifetime – and the cost per year. Against it is that it carries more than twice the hormone and has a noticeably thicker tube without preventing pregnancy any more reliably. A woman who only wants contraception and is happy with her periods has little reason to take the larger coil; Kyleena is therefore the model most often chosen at this practice.

It is different when the bleeding itself is the problem, when endometriosis makes every period an ordeal or when the menopause is approaching. Then Mirena brings something the smaller coils do not have: a licence as a treatment. A woman who chooses Mirena does so for a particular reason – and that reason is what this page is really about.

How reliably it prevents pregnancy

Mirena's Pearl Index is 0.2 in the first year; over the full eight years roughly one woman in a hundred becomes pregnant. For comparison: with the combined pill in typical use it is seven per year. That difference has nothing to do with the strength of the drug and everything to do with everyday life – a pill can be forgotten, a coil cannot. Vomiting, diarrhoea, antibiotics, time zones: none of it touches the effect. The licensing studies also counted the pregnancies that arose from an unnoticed expulsion or displacement, so the figure describes what actually happens, not what would happen under ideal conditions.

The full comparison with all methods is in the contraception comparison, that of all five coils in the IUD comparison.

How Mirena works

The levonorgestrel is released directly inside the uterus and acts very largely there. The level in the blood stays low – lower than under a progestogen-only pill, many times lower than under the three-monthly injection. That is why hormonal side effects are rarer with a coil than with products that distribute the same hormone through the bloodstream – and it is also why Mirena's larger dose matters less in the body than the number suggests.

Three effects work together:

The mucus in the cervix becomes thick and practically impassable for sperm – the most important mechanism.
Sperm that get through nonetheless lose their motility.
The lining of the uterus stays thin – more markedly with Mirena than with the smaller coils. That is also the mechanism that reduces bleeding so clearly.

Ovulation continues in most women. Your own cycle with its hormonal fluctuations carries on; only the bleeding becomes lighter or stops. Anyone hoping instead that the cycle will settle down is better served by another method.

What happens to the bleeding – year by year

This question decides the choice more often than any other, and with Mirena it has two answers: one for the first months and one for the years after. The figures from the licensing studies are stable and easy to summarise.

Months one to three: irregular spotting is the rule, not the exception. One woman in five has bleeding lasting more than eight days in this period. This is the phase in which most women doubt their decision, and it is the phase that passes – but with Mirena it passes no faster than with the smaller coils.

From month three to six: the average number of days with spotting falls from nine to four a month over the first six months. The share of women with prolonged bleeding drops from twenty to three in a hundred within the first three months. Periods become lighter and shorter, and period pain improves noticeably for many.

After a year: in about 17 women in a hundred, bleeding stops entirely for at least three months; in about one in five it becomes very infrequent or stops for good. In the rest it is as a rule much lighter than before insertion. Over the following years the share of women without bleeding rises a little further and then stays stable.

No bleeding is not a sign that something is building up. Under the local hormone effect the lining simply does not grow; there is nothing to shed. Medically there is nothing worrying about it. If periods stop after having been regular, a pregnancy test – once – is sensible; after that no longer, as long as nothing else points to a pregnancy. After removal the cycle returns.

When the coil is a treatment as well

In Austria Mirena is licensed to treat heavy menstrual bleeding – hypermenorrhoea. That is more than a formality: a woman who comes because her periods are too heavy and wants contraception anyway settles two questions with a single procedure. And a woman who does not need contraception gets a treatment that needs no daily tablet and keeps the uterus.

What “too heavy” means is hard to describe in millilitres and easy in everyday terms: when a pad or tampon is soaked through in under two hours, when bleeding lasts more than seven days, when clots appear, when you plan the day around the bleeding or when your iron level is on the floor. The effect is not immediate – in the first weeks bleeding can be more irregular than before – but it is considerable: within three to six months the amount of bleeding falls by more than three quarters in most women, and after a year many have hardly any period at all. The guidelines therefore list the hormonal coil as first-line treatment for heavy bleeding, ahead of tablets and well ahead of surgery.

The cause has to be clarified first. The commonest are fibroids, polyps, a thyroid disorder or adenomyosis – all four can be recognised on ultrasound and in the blood, and all four change something about the decision. A fibroid that distorts the cavity of the uterus rules the coil out; a polyp is removed first; a thyroid is treated first. Equally, an iron deficiency, which years of heavy bleeding almost always leave behind, needs treating. That is exactly why the consultation with ultrasound and blood count comes before the insertion appointment.

Mirena is also used for endometriosis and adenomyosis, because the thin lining and the low local hormone level often relieve the pain considerably. There is no licence for this, but decades of experience and a clear guideline recommendation; that is stated as such in the consultation.

Mirena in the menopause

In the years before the menopause several things coincide to which Mirena is a single answer. Periods often become heavier and more irregular in this time, contraception is still needed, and a woman who later starts hormone therapy for hot flushes needs a progestogen anyway to protect the lining of the uterus. Mirena covers all three points with one procedure – and it is the only coil licensed for the third.

The progestogen component of hormone therapy. A woman who takes oestrogen and has a uterus needs a progestogen with it, otherwise the lining grows unchecked. Mirena does that locally, for five years, combined with oestrogen as a tablet, gel or patch. The advantage over a progestogen tablet: the hormone stays largely in the uterus, bleeding usually stops within the first year – around forty women in a hundred have none in the last three months of the first year – and there is no second tablet to remember. In the first months spotting is the rule here too; more often in women still in the middle of the menopause than after it.

Contraception is needed for longer than many assume. Irregular cycles do not mean that ovulation has stopped. The rule of thumb: until one year after the last period if it came after your 50th birthday – otherwise until two years after. Under Mirena, however, the bleeding is lost as a marker. What remain are the other signs of the menopause – hot flushes, sweats, disturbed sleep, changes in the vagina and bladder – which occur regardless of the coil, because the missing oestrogen causes them and Mirena releases only a progestogen, locally. In case of doubt the hormone status can be measured in the blood; when that helps and when it merely confuses is settled in the consultation. More in the overview of the menopause.

When it is removed. At the end of its lifespan – or when contraception is no longer needed. If it also serves as the progestogen component of hormone therapy, the timing follows from that and is decided together, not by the calendar alone. For women after the menopause whose uterus has already shrunk, Mirena is not a first-choice method; insertion is then more difficult, and the decision is made case by case.

Who Mirena particularly suits

Women with heavy or painful periods, even if no contraception is needed at all. That is the commonest reason.
Women with endometriosis or adenomyosis, when the pain rules everyday life.
Women in the years before and during the menopause, when contraception, a bleeding disorder and possible hormone therapy coincide.
Women who want as few insertion appointments as possible. Eight years is the longest lifespan any hormonal coil offers.
After a thrombosis, with migraine with aura, and for smokers over 35. Mirena contains no oestrogen and does not raise the risk of thrombosis.
While breastfeeding. Milk production is not affected; the baby takes in only a tiny fraction of the dose through the milk. At this practice it is inserted twelve weeks after the birth.

When another choice is better

If it is only about contraception and bleeding is not a problem: then Kyleena does the same with less hormone and a thinner tube. For young women who have not given birth, Mirena is expressly not a first choice.
If hormones are not an option – by conviction, or because of a history of breast cancer – the copper or gold coil remains. Whether the hormonal coil slightly raises the risk of breast cancer is debated in large observational studies and is not firmly established; after breast cancer it is not used.
If you plan a pregnancy in one or two years, the sums are worth doing: inserting a coil for eight years and removing it after eighteen months is possible, but expensive.

It is not inserted in pregnancy, with an acute genital infection, with unexplained bleeding, with malformations or large fibroids that distort the cavity of the uterus, with hormone-dependent tumours such as breast cancer, with cell changes or cancer of the cervix or uterus, or with acute liver disease. Unexplained bleeding is the most important point: because Mirena itself causes bleeding irregularities in the first months, it has to be established beforehand that the lining is healthy – otherwise the coil masks what should have been investigated.

The procedure: two appointments

The first appointment is for the consultation and the pre-examination: history, bleeding pattern, family planning, then an ultrasound to assess the size and position of the uterus, a wet mount and swabs – and, with heavy bleeding, a blood count. By the end it is settled whether Mirena fits or another coil, and that there is no infection that could be carried upwards at insertion.

At the second appointment the coil is inserted. The procedure takes a few minutes: the cervix is prepared, the coil is introduced in its tube and released, the threads are trimmed, the position is confirmed by ultrasound. The best time is within the first seven days of the cycle – then Mirena works immediately, the cervix is naturally a little softer, and a pregnancy is ruled out. At any other time, additional protection with condoms for seven days makes sense. After a birth this practice waits twelve weeks until the uterus has returned to its normal size; the risk of perforation is raised in the first months after a birth and while breastfeeding, and expulsion is more likely.

That the two do not happen on the same day is deliberate. The separation is the reason the second appointment is short: there is nothing left to discuss, nothing to wait for and nothing to rule out.

What insertion feels like

Uncomfortable – that has to be said honestly. Expect a short, sharp cramping pain at the moment the insertion tube passes the cervix, and afterwards a dragging pain like strong period pain that eases over a few hours. A painkiller an hour beforehand is sensible. Some women take the rest of the day off; many go back to work.

Mirena's tube measures 4.4 millimetres against 3.8 for Jaydess and Kyleena. That sounds like little and is not – above all for women who have not given birth. How strong it is depends considerably on how carefully it is prepared and how much time is allowed; that is precisely what the separate consultation is for. If insertion is difficult or the pain unusual, the position is checked by ultrasound straight away.

Checks and everyday life

A check takes place four to six weeks after insertion, then yearly. The ultrasound shows whether the coil is in the right place; it can shift or be expelled, most likely in the first months and most likely during a period. That happens to about two to five women in a hundred – more often with obesity and in women who previously bled very heavily. Because Mirena reduces bleeding so clearly, a period that suddenly becomes heavy again is a sign that needs checking: it can mean that the coil is no longer sitting properly.

The removal threads can be felt now and then, for example in the shower. If they can no longer be found or have become noticeably longer, use additional contraception and make an appointment. Do not pull on the threads.

In everyday life there are hardly any restrictions. Sport, sauna and swimming are possible without limitation, tampons too. With a menstrual cup, the vacuum should be released deliberately before it is taken out so that it does not pull on the threads. In the first week after insertion, baths, swimming pools and tampons are discouraged because the cervix is still slightly open. Mirena contains no metal; magnetic resonance imaging is possible with the coil in place.

Side effects and risks

The commonest unwanted effects are the changes in bleeding already described in the first months, plus headaches, lower abdominal and pelvic pain and vaginal inflammation in some women. Enlarged follicles – functional ovarian cysts – are seen in about twelve women in a hundred; they are usually harmless, disappear on their own and rarely need more than a check. Occasionally there is depressed mood, nervousness, reduced libido, nausea, acne, breast tenderness and weight gain. They are rarer than with products that distribute the same hormone through the bloodstream, but they occur, and they are not played down here.

Serious events are rare. Perforation of the uterine wall at insertion is in the order of one in a thousand and is usually without consequences if recognised in time; it is more frequent in the first 36 weeks after a birth, while breastfeeding and with a retroverted uterus. An ascending infection is slightly more likely in the first three weeks after insertion, and not thereafter – the cause is not the coil but an existing infection carried upwards. That is exactly what the consultation with the swabs protects against. Fever, increasing lower abdominal pain or foul-smelling discharge in this period need to be checked the same day.

An ectopic pregnancy is very rare under Mirena – about one in a thousand users – and thus rarer than in women who use no contraception at all. If a woman does become pregnant with the coil in place, however, the share of ectopic pregnancies among those few cases is raised. Lower abdominal pain together with a missed period, or with bleeding that suddenly returns after a long gap, therefore needs prompt assessment.

Costs in Vienna

The insertion appointment with Mirena costs 750 euros at this private (Wahlarzt) practice. That includes the check-up, the ultrasound, a pregnancy test, the wet mount, the medical preparation, the insertion and the coil itself. The preceding contraception consultation with swabs is charged at 250 euros.

Spread over eight years that is around 94 euros a year or just under eight euros a month – less than any pack of pills, with considerably higher reliability. You submit the invoice to your health insurer, which refunds 80 per cent of the corresponding public tariff – that applies to the Austrian public system; anyone insured privately or abroad submits the invoice to their own insurer. Contraceptives themselves are not covered by public insurance in Austria. All amounts are listed under Fees.

After eight years – or sooner

At the end of the licensed period Mirena has to be replaced or removed – protection is no longer assured after that. Exchange and re-insertion take place in one appointment: old one out, new one in. Removal takes seconds and hurts far less than insertion. A woman who has Mirena for heavy bleeding discusses the exchange after five years – or sooner, as soon as the bleeding becomes heavier again.

If instead you want a child: fertility returns immediately. Unlike after the three-monthly injection there is no delay; a pregnancy is possible in the very first cycle afterwards. Folic acid should be started four weeks before the planned conception, not afterwards – the ovulation calculator helps with the planning.

What happens next

Whether Mirena, Kyleena or Jaydess is the right one is decided by your history, your bleeding pattern and your family planning – not by a table. The next step is therefore the contraception consultation. Arranging an appointment, or compare beforehand: IUD comparison, Kyleena, Jaydess and the hormonal coil in overview.

The leaflet below is a translation of the version that has stood on this website for years. A newer official version exists: Gebrauchsinformation Mirena, June 2026, in the wording of the Austrian medicines register (German). The newer version is the authoritative one.

Patient information leaflet, Mirena 52 mg

This is a translation. Below is the manufacturer's patient information leaflet for Mirena 52 mg intrauterine delivery system (levonorgestrel), Bayer, rendered into English for convenience. The authoritative text is the German original, which is reproduced word for word on the German page Hormonspirale and enclosed with the product. This translation replaces neither that leaflet nor the conversation at the practice.

1. What Mirena is and what it is used for

Mirena is an intrauterine delivery system (IUS, a “hormonal coil” inserted into the uterus) and is used for or in

contraception (the prevention of pregnancy)
hypermenorrhoea (very heavy periods)
endometrial protection (protection against excessive growth of the lining of the uterus) during hormone replacement therapy with an oestrogen.

Mirena consists of a plastic body in the shape of a T. On the vertical part there is a cylinder containing the progestogen levonorgestrel, a substance similar to the body's own corpus luteum hormone. The effectiveness of Mirena rests mainly on a local hormonal effect in the uterus, the hormone being released evenly in low doses (about 20 μg in 24 hours at the start, 10 μg/24 hours after 5 years) into the uterus and thereby suppressing the build-up of the lining. The contraceptive effect also rests on a thickening of the mucus in the cervix, through which sperm cannot enter the uterus. At the same time Mirena relieves the symptoms occurring during the period. Children and adolescents: Mirena must not be used before the first period (menarche).

The contraceptive effectiveness of Mirena has been examined in 5 larger clinical studies. With correct use of Mirena in accordance with the instructions for insertion, 2 in 1000 women become pregnant in the 1st year of use, and 7 in 1000 women after 5 years of use. This includes pregnancies due to unnoticed expulsion and perforation.

With excessively heavy periods (hypermenorrhoea) the amount and duration of bleeding are reduced through the direct influence on the lining of the uterus. If Mirena is used as part of hormone replacement therapy with an oestrogen for menopausal symptoms, regardless of how the oestrogen is administered, it prevents excessive growth of the lining of the uterus.

2. What you need to know before you use Mirena

General remarks
Before you can use Mirena, your doctor will ask you some questions about your personal medical history and that of your immediate family. Like other hormonal contraceptives, Mirena does not protect against HIV infection (AIDS) or other sexually transmitted diseases.

Warnings and precautions
Please talk to your doctor or pharmacist before Mirena is used. If you are using Mirena as part of hormone replacement therapy with an oestrogen, the safety information in the leaflet of the oestrogen preparation must be observed.

Mirena must not be used:

if you are pregnant or pregnancy is suspected in you,
if you have, or are suspected of having, a tumour whose growth is influenced by sex hormones (for example breast cancer),
if you have current or recurrent inflammation of the internal reproductive organs,
if you have an infection of the lower genital tract (of the vagina or of the cervix) (cervicitis),
if you have inflammation of the lining of the uterus after a birth,
if you have had an infection of the uterus after a miscarriage (within the last 3 months),
if you have an increased susceptibility to infection,
if you have cell changes of the cervix (cervical dysplasia),
if you have malignant tumours of the cervix or of the uterus,
if you have unexplained bleeding from the uterus,
if you have congenital or acquired malformations of the cervix or of the uterus, including fibroids, which distort the cavity of the uterus,
if you have acute liver disease or a liver tumour,
if you are allergic to levonorgestrel or to any of the other ingredients of this medicine listed in section 6.

Particular care is required when using Mirena

If you suffer from one of the conditions named below, Mirena should only be used after seeing a specialist, and should where appropriate be removed if one of these conditions occurs for the first time while Mirena is in place:

migraine; migraine with visual disturbance or other symptoms suggesting a temporary disturbance of the blood supply to the brain (for example difficulty in speaking or hearing, dizziness);
exceptionally severe headache;
jaundice;
a marked rise in blood pressure;
severe vascular disease such as stroke or heart attack;
acute venous thrombosis (blood clots in the veins). Mirena must be used with caution with congenital heart disease or heart valve disease carrying a risk of infective endocarditis (inflammation of the lining of the heart).

When it is inserted or removed, antibiotics should be taken as a precaution. In women with diabetes who use Mirena, blood sugar levels should be monitored. A change in diabetes treatment is not normally necessary for the duration of Mirena use, however.

For young women who have not yet given birth, or for women in the menopause with a shrunken uterus, Mirena is not a method of first choice.

Mirena is not suitable as a post-coital contraceptive (an “emergency contraceptive” immediately after intercourse).

Medical examinations/consultation

Before Mirena is inserted, your doctor will carry out a gynaecological examination (including the breasts and a smear). The position and size of the uterus are determined and pregnancy or sexually transmitted diseases are excluded; genital infections must be treated with demonstrable success. Your doctor will hand you the package leaflet for your information.

4 to 12 weeks after insertion you should attend a check-up so that the position of Mirena can be verified.

Further checks should take place at yearly intervals, and at shorter intervals if clinically necessary. Insertion or removal of Mirena can lead to pain and bleeding as well as to circulatory disturbances with loss of consciousness due to a sudden fall in blood pressure and pulse, or, where epilepsy is known, to seizures. Irregular bleeding can mask some symptoms of serious changes of the lining of the uterus (endometrial polyps and carcinoma), which is why appropriate diagnostic measures should be taken. Since irregular bleeding and spotting are usual in the first months after insertion, pathological changes of the lining of the uterus (the endometrium) are to be excluded before Mirena is inserted. This also applies where Mirena continues to be used for endometrial protection during oestrogen replacement therapy following previous use as a contraceptive. If irregularities of bleeding occur during prolonged use, appropriate diagnostic measures must be taken.

Oligomenorrhoea/amenorrhoea (infrequent/absent periods):

About 20% of women of childbearing age gradually develop oligomenorrhoea and/or amenorrhoea. If no bleeding begins within 6 weeks of the start of the last period, the possibility of pregnancy must be considered. A repeat pregnancy test is not necessary in women with no period unless other signs suggest pregnancy. When Mirena is used in combination with continuous oestrogen replacement therapy, bleeding mostly ceases gradually within the first year.

Infections of the internal reproductive organs

The insertion tube protects Mirena from contamination with organisms during insertion; it was developed in order to keep the risk of inflammation as low as possible. In users of copper intrauterine devices the frequency of infections of the internal reproductive organs is highest during the first month after insertion and decreases thereafter. Known risk factors for infections of the internal reproductive organs are sexually transmitted diseases. The risk of infection with sexually transmitted diseases can be reduced by using condoms. Infections of the internal reproductive organs can have serious consequences which affect fertility and increase the risk of pregnancies outside the uterus. As with other gynaecological or surgical procedures, a serious infection or sepsis (a very serious general infection which can be fatal) can occur after an intrauterine device has been inserted. With endometritis (inflammation of the lining of the uterus) or inflammation in the pelvic area, or if an acute infection is serious or does not respond to treatment within a few days, Mirena must be removed by your doctor without delay. See your doctor immediately if you have the following symptoms: persistent pain in the lower abdomen, fever, pain during sexual intercourse or irregular bleeding. Severe pain or fever occurring shortly after insertion can mean that you have a serious infection which must be treated immediately.

Expulsion

A partial or complete expulsion is mostly accompanied by bleeding or pain, but it can also occur unnoticed and lead to a loss of contraceptive protection. A partial expulsion can impair the effectiveness of Mirena. If the IUS is expelled, you are no longer protected against pregnancy. Since Mirena reduces the amount of menstrual bleeding, heavier bleeding can indicate an expulsion. Your doctor will explain to you how you can feel the removal threads of Mirena yourself. You should regularly satisfy yourself that the threads of the device are present, ideally directly after your period. If you cannot feel the threads or have indications of an expulsion, you should refrain from sexual intercourse or use another contraceptive and consult your doctor. A displaced Mirena should be removed and can be replaced by a new one at any time. See your doctor promptly.

Perforation

Perforation of or penetration into the wall of the uterus mostly occurs during the insertion of Mirena, although it may only be discovered later. A Mirena that has been displaced outside the cavity of the uterus cannot effectively prevent pregnancy and must be removed as soon as possible. Surgery may be necessary in order to remove the Mirena. The risk of perforation when Mirena is inserted is increased in breastfeeding women and in women up to 36 weeks after a birth, and may be increased in women with a retroflexed (backward-angled) uterus.

If you suspect that a perforation has occurred in you, see a doctor without delay and remind them that you have a Mirena in place, particularly if it is not the doctor who carried out the insertion.

Possible signs and symptoms of a perforation:

severe pain (similar to period cramps)
heavy bleeding (after insertion)
pain or bleeding lasting more than a few weeks
sudden changes in your period
pain during sexual intercourse
you can no longer feel the removal threads (see section 2, “Warnings and precautions” – threads that cannot be found)

Breast cancer

Women who take a combined oral contraceptive (“the pill”) have a slightly increased risk of breast cancer, chiefly with contraceptives containing oestrogen and progestogen. The increased risk gradually returns to the baseline risk for the woman's age within 10 years of stopping “the pill”. Since Mirena is likewise a hormonal contraceptive, it can be assumed that such a breast cancer risk also exists with the use of Mirena, possibly as great as with the use of combined oral contraceptives.

Ectopic pregnancy (pregnancy outside the uterus)

Women with a previous pregnancy outside the uterus, operations on the fallopian tubes or infections of the internal reproductive organs have an increased risk of pregnancies outside the uterus. If you have lower abdominal pain while using Mirena, particularly in connection with the absence of your period or with sudden bleeding after a longer bleeding-free interval (amenorrhoea), the possibility of a pregnancy outside the uterus must be considered. Very rarely a pregnancy outside the uterus can occur while Mirena is being used (in approximately 1 in 1000 women). The risk is higher in women who use no contraceptive method (3 to 5 in 1000 women per year). The absolute risk of a pregnancy outside the uterus is low with Mirena. If a Mirena user does become pregnant, however, the relative probability of a pregnancy outside the uterus is increased. See your doctor immediately if you suddenly suffer pain in the lower abdomen.

Threads that cannot be found

If at check-ups with the doctor the removal threads are not visible at the cervix, pregnancy must first be excluded. The removal threads may have moved into the uterus or the cervical canal and may become visible again during the next period. Once pregnancy has been excluded, the removal threads can usually be brought into the correct position by your doctor with the aid of a suitable instrument. If this is not successful, Mirena may have been expelled or may have perforated the wall of the uterus. Its correct position can be verified by ultrasound; otherwise Mirena can be located by X-ray examination.

Enlarged follicles (functional ovarian cysts)

The contraceptive effect of Mirena does not as a rule rest on inhibition of ovulation. Since Mirena acts mainly locally, women of childbearing age usually have cycles with ovulation and rupture of the follicle. Sometimes the regression of the follicle is delayed. These enlarged follicles cannot be distinguished by the doctor from ovarian cysts (fluid-filled growths of the ovary). Enlarged follicles were found in approximately 12% of Mirena users. Mostly these follicles cause no symptoms; rarely, pain in the pelvis or pain during sexual intercourse occurs. In most cases the enlarged follicles disappear spontaneously within 2 or 3 months. Should this not be the case, they are to be monitored by ultrasound or other diagnostic/therapeutic measures are to be initiated. In individual cases surgery may be necessary.

Psychiatric disorders:

Some women using hormonal contraceptives such as Mirena report depression or depressed mood. Depression can be serious and may occasionally lead to suicidal thoughts. If you experience mood changes and depressive symptoms, seek medical advice from your doctor as soon as possible.

Other medicines and Mirena
Tell your doctor or pharmacist if you are taking or using, have recently taken or used, or intend to take or use any other medicines. The breakdown of progestogens can be accelerated by the simultaneous administration of certain (enzyme-inducing) substances such as anticonvulsants (medicines against seizures; for example phenobarbital, phenytoin, carbamazepine) and anti-infectives (medicines against infections; for example rifampicin, rifabutin, nevirapine, efavirenz). The influence of these medicines on the contraceptive effect of Mirena is not known, but is assessed as not significant because of its predominantly local action.

Pregnancy, breastfeeding and fertility

Pregnancy

Mirena must not be used during an existing or suspected pregnancy. If you believe you are pregnant, see your doctor immediately. It is recommended that Mirena be removed, since the risk of a spontaneous miscarriage or premature labour is increased with a Mirena in place. Removal of Mirena or examination of the uterus can lead to a spontaneous miscarriage. If Mirena cannot easily be removed, termination of the pregnancy should be considered. If you wish to continue the pregnancy and Mirena cannot be removed, your doctor will inform you about any risks and the possible consequences of a premature birth. The course of such a pregnancy must be monitored carefully. A pregnancy outside the uterus must be excluded. Report to your doctor any symptoms that suggest complications with the pregnancy, such as cramping pain in the lower abdomen with fever. Because Mirena is used in the uterus, an effect on the unborn child (for example masculinisation) cannot be excluded. Experience of the outcome of pregnancies with Mirena is limited because of its high contraceptive effectiveness. In the cases in which a pregnancy has been carried to term with a Mirena in place, there is to date no indication of malformations or complications caused by Mirena.

Breastfeeding

Levonorgestrel has been found in breast milk (approximately 0.1% of the dose is taken up by the infant); however, it is unlikely that the dose released by Mirena after insertion into the cavity of the uterus carries a risk for the child. It appears to have no harmful effects on the growth or development of the child when Mirena is used six weeks after the birth. Progestogen-only methods appear to have no influence on the quantity or quality of breast milk.

In rare cases bleeding from the uterus has been reported in women who used Mirena while breastfeeding.

Fertility

The use of Mirena has no effect on future fertility. After Mirena is removed, women attain the same fertility as before. Driving and using machines

No effects on the ability to drive or to use machines have been observed.

Mirena contains barium sulphate
Mirena contains barium sulphate and is visible on X-ray examinations.

3. How to use Mirena

Mirena is inserted into the cavity of the uterus by the doctor. The maximum duration in place is 5 years. For contraception Mirena is as effective as the most effective copper coils available today. In clinical studies about 2 pregnancies occurred in the first year of using Mirena among 1000 women. In women undergoing hormone replacement therapy, Mirena can be used in combination with oral (hormone tablets) or transdermal oestrogen preparations (hormone patches on the skin). The insertion and removal of Mirena may only be carried out by a specialist experienced in and/or specially trained in handling Mirena.

Contraception or treatment of hypermenorrhoea (very heavy periods):
In women of childbearing age Mirena should be inserted within 7 days of the start of the period. Mirena can be replaced by a new intrauterine device at any point in the cycle. After a miscarriage in the first third of pregnancy, Mirena can be inserted immediately afterwards. After a birth, insertion should only be carried out once the uterus has fully returned to its normal size, but not earlier than 6 weeks after the birth (see section 2, “What you need to know before you use Mirena – perforation”). If the return to normal size is substantially delayed, waiting until up to 12 weeks after the birth should be considered, since the risk of perforation of the uterus is increased after a birth. If insertion is difficult and/or unusual pain or bleeding occurs during or after insertion, an ultrasound check should be carried out without delay in order to exclude a perforation.

Endometrial protection (protection against excessive growth of the lining of the uterus) during oestrogen replacement therapy:

If Mirena is used to protect the lining of the uterus during oestrogen replacement therapy, insertion can take place at any time in women who no longer have bleeding, or during the last days of the bleeding or of the withdrawal bleed.

Removal/replacement:

Mirena is removed by pulling gently on the removal threads with forceps. If the removal threads are not visible and the system is in the cavity of the uterus, Mirena can be removed with the aid of a particular grasping forceps. This may make dilatation (widening) of the cervical canal necessary. Mirena should be removed after 5 years. If you wish to stay with the same method, a new intrauterine device can be inserted immediately after the previous one has been removed. If pregnancy is not desired, Mirena should in women of childbearing age be removed during the period, provided there is a menstrual cycle. If Mirena is removed in the middle of the cycle and you have had unprotected sexual intercourse within the last week, there is a risk of pregnancy unless a new Mirena is inserted immediately after removal. After Mirena has been removed, the intrauterine device should be checked to make sure it is intact. Where there have been difficulties during removal, it has been reported in individual cases that the hormone cylinder slides over the horizontal arms and that these become covered inside the cylinder. Once the completeness of the IUS has been established, no further action is necessary. The end knobs of the horizontal arms usually prevent the cylinder from becoming completely detached from the T-shaped body.

Notes on handling

Mirena is supplied in sterile packaging which may only be opened immediately before insertion. Once removed from the pack, the product must be handled under sterile conditions. If the sterile packaging is damaged, Mirena is to be discarded.

Contact your doctor immediately if you experience the following (see also sections 2 and 4):

if you can no longer feel the threads in your vagina.
if your partner feels the removal threads during sexual intercourse.
if you or your partner can feel the lower end of the Mirena. Avoid sexual intercourse until your doctor has checked that the IUS is correctly in place.
if you think you are pregnant.
if you have persistent abdominal pain, fever or unusual discharge from the vagina; this may be a sign of an infection. Infections have to be treated immediately.
if you have pain or discomfort during sexual intercourse; this may be a sign of an infection or an ovarian cyst, for example, or an indication that the Mirena is not in the correct position.
if sudden changes occur in your periods (for example if you have little or no bleeding and begin to have persistent bleeding or pain, or begin to bleed heavily); this may indicate, for example, that the Mirena is not in the correct position or has been expelled.
severe pain (like period cramps) or heavy bleeding after the insertion of the Mirena.
if you have other symptoms, such as migraine; recurrent intense headache, sudden visual disturbance, jaundice and a marked rise in blood pressure.

The use of sanitary towels is recommended. If you use tampons, you should change them carefully and not pull on the threads of Mirena.

Additional notes on particular groups of patients

Older patients

The use of Mirena in women over 65 has not been studied.

Patients with impaired liver function

Mirena must not be used in women with acute liver disease or liver cancer (see section 2, “Mirena must not be used”).

Patients with impaired kidney function

The use of Mirena in women with impaired kidney function has not been studied.

If you have any further questions about the use of Mirena, ask your doctor or pharmacist.

4. Possible side effects

Like all medicines, this medicine can cause side effects, although not everybody gets them.

What follows is a list of possible side effects ordered by frequency:

Side effects occur more often during the first months after Mirena is inserted and subside with longer use. In addition to the undesirable effects listed in section 2, “What you need to know before you use Mirena”, the following side effects have been reported in women using Mirena.

In women of childbearing age the average number of days per month on which spotting occurs falls gradually from nine to four days in the first six months of use. The proportion of women with prolonged bleeding (more than eight days) falls from 20% to 3% in the first three months of use. In clinical studies, 17% of women showed amenorrhoea lasting at least three months in the first year of use.

In combination with oestrogen replacement therapy, most Mirena users during or after the menopause had spotting and irregular bleeding during the first months of treatment. After that, bleeding and spotting decreased and about 40% of users have no further bleeding during the last 3 months of the first year of use. Disturbances of bleeding were commoner in women during the menopause compared with women after the menopause.

The frequency of enlarged follicles depends on the diagnostic method used; in clinical studies enlarged follicles were found in 12% of Mirena users. Most follicles are asymptomatic (cause no symptoms) and disappear within 3 months.

Very common side effects: affects more than 1 user in 10

Headache, abdominal pain, pain in the pelvis, changes in the bleeding pattern: heavier bleeding (hypermenorrhoea), infrequent periods (oligomenorrhoea), reduced bleeding (hypomenorrhoea), absence of periods (amenorrhoea), spotting, inflammation of the vagina and the external genitals (vulvovaginitis), discharge from the vagina.

Common side effects: affects 1 to 10 users in 100

Depressed mood, depression, nervousness, reduced sex drive (libido), migraine, nausea, acne, excessive hair growth with a male pattern of distribution (hirsutism), back pain, ovarian cysts, painful periods (dysmenorrhoea), breast pain, breast tenderness, expulsion of Mirena, weight gain.

Uncommon side effects: affects 1 to 10 users in 1,000

Wind, hair loss (alopecia), itching (pruritus), eczema, discolouration of the skin (chloasma), increased pigmentation of the skin (hyperpigmentation), inflammation in the pelvic area, inflammation of the lining of the cervix (cervicitis) and of the uterus (endometritis), Papanicolaou smear normal, class II, perforation of the uterus, retention of fluid in the tissues (oedema).

Rare side effects: affects 1 to 10 users in 10,000

Rash, hives (urticaria).

Infections

Cases of sepsis (a very serious general infection which can be fatal) have been reported after the insertion of the intrauterine device (see section 2, “What you need to know before you use Mirena”).

Pregnancy, the postnatal period and perinatal conditions

Should you become pregnant with a Mirena in place, the probability of a tubal or abdominal pregnancy developing is increased (see section 2 under “Pregnancy outside the uterus”). The removal threads may be noticeable to your partner during sexual intercourse.

Disorders of the reproductive organs and the breast

Cases of breast cancer have been reported (the frequency is not known).

The following side effects have been observed during the insertion and removal of Mirena:

Pain, bleeding, circulatory disturbances with dizziness or brief loss of consciousness (syncope). In women with epilepsy, seizures may occur.

Reporting of side effects

If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly (see the details below). By reporting side effects you can help provide more information on the safety of this medicine.

Federal Office for Safety in Health Care (Bundesamt für Sicherheit im Gesundheitswesen)
Traisengasse 5
1200 Vienna
Fax: + 43 (0) 50 555 36207
Website: http://www.basg.gv.at/

5. How to store Mirena

Keep this medicine out of the sight and reach of children. Do not open the blister. The pack should only be opened by your doctor or the healthcare staff. Do not use this medicine after the expiry date stated on the outer carton and on the blister pack after “Use by”. The expiry date refers to the last day of the month stated. Do not dispose of medicines in waste water or household waste. Ask your pharmacist how to dispose of the medicine when you no longer use it. You will thereby be helping to protect the environment.

6. Contents of the pack and other information

What Mirena contains:

The active substance is levonorgestrel. 1 intrauterine device contains 52 mg of levonorgestrel.

The other ingredients are: polydimethylsiloxane elastomer, polyethylene, barium sulphate, black iron oxide (E172).

What Mirena looks like and contents of the pack:

Mirena is an intrauterine delivery system and is available in a pack of 1.

Marketing authorisation holder and manufacturer:
Marketing authorisation holder:

Bayer Austria Ges.m.b.H.
1160 Vienna

Manufacturer:
Bayer Oy, 20101 Turku, Finland
Authorisation no.: 1-21529

This leaflet was last revised in December 2018.

Frequently asked questions

How long can Mirena stay in?

For contraception, up to eight years. A woman who has it for heavy bleeding or as the progestogen component of hormone therapy replaces it after five years – with heavy bleeding also sooner, as soon as the bleeding returns.

What is the difference between Mirena and Kyleena?

Mirena contains more than twice the hormone, stays in for up to eight years instead of five, reduces bleeding more strongly and is additionally licensed to treat heavy periods and for hormone therapy. Kyleena is smaller and lower in hormone with almost the same reliability. A woman who comes because of her bleeding usually gets Mirena; one who wants contraception, usually Kyleena.

Does Mirena help with heavy periods?

Yes, that is one of its three licences. Within three to six months the amount of bleeding falls by more than three quarters in most women; after a year many have hardly any period at all. The cause is clarified first – fibroids, polyps, thyroid, adenomyosis – because it can change the decision.

Can Mirena be used in hormone replacement therapy?

Yes, as the progestogen component for five years, combined with oestrogen as a tablet, gel or patch. It is the only coil with this licence. Under this combination bleeding usually stops within the first year.

How quickly does Mirena work?

If it is inserted within the first seven days of the cycle, immediately. At a later point, additional protection with condoms for seven days is sensible. The effect on bleeding takes longer – three to six months.

Do you put on weight with Mirena?

Weight gain is listed in the patient leaflet as an occasional side effect. In the licensing studies, weight development did not differ materially from that without hormonal contraception. In case of doubt it helps to compare your weight before insertion and six months later, rather than relying on impressions.

Can Mirena affect my mood?

The patient leaflet lists depressed mood as an occasional side effect, and that possibility is not played down here. At the same time, changes in mood rarely have a single cause – life circumstances, sleep and the thyroid all play a part. If you notice a change after insertion, raise it. Where psychotherapeutic assessment would help, we refer you on rather than dismiss the question.

Will I notice the menopause starting with Mirena in place?

Not from your periods – they are lost as a marker. But from the other signs: hot flushes, sweats, disturbed sleep, changes in the vagina and bladder. They arise from the missing oestrogen, and the coil changes nothing about that. In case of doubt a hormone test in the blood helps.

Can Mirena move without my noticing?

Yes, hence the check after four to six weeks and yearly thereafter. A warning sign is a period that suddenly becomes heavy again after having become light under Mirena. You can also feel for the threads now and then; if they can no longer be found, use additional contraception and make an appointment.

Does Mirena protect against sexually transmitted infections?

No. For that the condom is the only method – with changing partners, in addition.

Sources

Gebrauchsinformation Mirena 20 Mikrogramm/24 Stunden Intrauterinpessar (levonorgestrel), Bayer Austria. Austrian medicines register (BASG), authorisation no. 1-21529, June 2026.
Jensen JT et al.: Contraceptive efficacy and safety of the 52-mg levonorgestrel intrauterine system for up to 8 years: findings from the Mirena Extension Trial. American Journal of Obstetrics and Gynecology 2022;227(6):873.e1–873.e12.
National Institute for Health and Care Excellence: Heavy menstrual bleeding: assessment and management. NICE Guideline NG88, London 2018, updated 2021.
Andersson JK, Rybo G: Levonorgestrel-releasing intrauterine device in the treatment of menorrhagia. British Journal of Obstetrics and Gynaecology 1990;97(8):690–694.
Faculty of Sexual & Reproductive Healthcare: Intrauterine Contraception. FSRH Clinical Guideline, London 2023.
Heinemann K et al.: Risk of uterine perforation with levonorgestrel-releasing and copper intrauterine devices in the European Active Surveillance Study on Intrauterine Devices. Contraception 2015;91(4):274–279.
German Society of Gynaecology and Obstetrics et al.: Peri- and postmenopause – diagnosis and interventions. S3 guideline, AWMF register no. 015-062, 2020.
World Health Organization: Medical eligibility criteria for contraceptive use. 5th edition, Geneva 2015.

This text is general information and cannot replace a consultation: it does not know your history and cannot examine you. If something about your situation differs from what is described here, that difference is what matters.

Arrange an appointment →

Read on

The hormonal coil

The most reliable reversible contraception – and at the same time a treatment for heavy bleeding. Everything a…

IUD & coils

The only reversible method as reliable in practice as on paper – and an honest answer to the question about fi…

Jaydess

The smallest coil with the least hormone – often the first one. Why three years is sometimes exactly the right…

Kyleena

The most frequently chosen hormonal coil: as small as Jaydess, effective for five years. Who it suits – and wh…