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Active substance(s): LEVONORGESTREL
20 micrograms/24 hours
intrauterine delivery system (levonorgestrel)
Date of Fitting:
First check-up visit:
About this booklet
Please read this booklet carefully before you
decide to have Mirena fitted.
It provides you with some useful information
about Mirena. The information in this booklet
applies only to Mirena. If you have any
questions or are not sure about anything,
please ask your doctor or nurse.
In this booklet:
1. What Mirena is and what it is used
2. Before you have Mirena fitted
3. How and when Mirena is used
4. Possible side effects
5. Further information
1. What Mirena is and what it is used
Mirena is an intrauterine system (IUS) placed
inside the womb (uterus) where it slowly
releases the hormone levonorgestrel. It can be
used in the following three ways:
1. As an effective long-term and reversible
method of contraception.
2. For reducing menstrual blood flow, if
you suffer from heavy periods (heavy
It can be used for contraception and heavy
menstrual bleeding until it is removed or up
to a maximum of 5 years.
3. If you are going through the menopause
Mirena can be used in conjunction with
an oestrogen as part of a hormone
replacement therapy (HRT) regimen to
protect the lining of your womb.
Not so much is known about how well
Mirena protects the lining of the womb
beyond 4 years of use in women who are
taking oestrogen to treat menopausal
symptoms. Therefore, if you are using it in
this way, your doctor or nurse will remove
your Mirena after 4 years. Your doctor will
be able to advise you further.
Children and adolescents
Mirena is not indicated for use before the first
menstrual bleeding (menarche).
How does Mirena work?
As a contraceptive:
The hormone in Mirena prevents pregnancy by:
R controlling the monthly development of
the womb lining so that it is not thick
enough for you to become pregnant
R making the mucus in the opening to the
womb (the cervical canal) thicker, so that
the sperm cannot get through to fertilise
R preventing the release of eggs (ovulation)
in some women.
There are also some effects on the lining of
the womb caused by the presence of the
T-shaped frame of the Mirena device.
In the treatment of heavy menstrual
The hormone in Mirena reduces menstrual
bleeding by controlling the monthly
development of the womb lining, making it
thinner, so that there is less bleeding every
As part of an HRT regimen:
The menopause is a gradual process which
usually takes place between the ages of
about 45 and 55. Although the menopause is
natural, it often causes distressing
symptoms such as hot flushes and night
sweats. These symptoms are due to the
gradual loss of the female sex hormones
(oestrogen and progestogen) produced by the
Oestrogens can be used to relieve the
menopausal symptoms. However, taking
oestrogens alone increases the risk of
abnormal growth or cancer of the lining of
the womb. Taking a progestogen, such as the
hormone in Mirena (levonorgestrel), as part of
an HRT regimen lowers this risk by protecting
the lining of the womb.
2. Before you have Mirena fitted
Your doctor or nurse will carry out some
tests before you have Mirena fitted to make
sure that it is suitable for you to use. This
will include a pelvic examination so that
pregnancy and sexually transmitted diseases
can be excluded and may also include other
examinations such as a breast examination, if
your doctor or nurse feels this is appropriate.
Genital infections will need to be successfully
treated before you can have Mirena fitted.
If Mirena is to be fitted for HRT use your
doctor will firstly carry out an assessment of
your symptoms to ensure that treatment is
only initiated for symptoms that adversely
affect your quality of life. Such an assessment
should be repeated by your doctor at least
annually. You should also consult the Patient
Information Leaflet of the oestrogen product
that is to be used in conjunction with Mirena
before starting your HRT regimen as there are
some important risk factors associated with
HRT that you should consider, such as the
risk of endometrial cancer, breast cancer and
blood clots. You may feel pain or have some
bleeding during insertion.
If you have epilepsy, tell the doctor or nurse
fitting the Mirena because, although rare, a
fit can occur during insertion. Some women
might feel faint after the procedure. This is
normal and your doctor or nurse will tell you
to rest for a while.
Do not use Mirena and please tell your doctor
or nurse if you:
R are pregnant or suspect that you may be
R have or have had any type of cancer or
suspected cancer including blood cancer
(leukaemia) unless in remission, uterine,
cervical and breast cancer
R currently have or have had recurrent pelvic
R have or have had inflammation of the
neck of the womb (cervix)
R have an unusual or unpleasant vaginal
discharge, or vaginal itching as this may
indicate an infection
R have or have had inflammation of the
lining of your womb following delivery of
R have or have had an infection of the womb
after delivery or after abortion during the
past 3 months
R have any condition which makes you
susceptible to infections. A doctor will
have told you if you have this
R have or have had an abnormal smear test
(changes in the cervix)
R have undiagnosed vaginal bleeding
R have an abnormal womb or abnormal
growths in the womb (fibroids) which
distort the uterine cavity
R have or have had liver problems
R have or have had trophoblastic disease. A
doctor will have told you if you have this
R are sensitive to the hormone levonorgestrel
or to any of the ingredients in Mirena (see
section 5 ‘What Mirena contains’).
Mirena must not be used as part of an HRT
regimen if you have had a stroke, heart attack
or any heart problems.
Mirena may not be suitable for all women.
Consult your doctor or nurse if you:
R have or develop migraine with visual
disturbances, unusually bad headaches
or if you have headaches more often than
R have yellowing of the skin or whites of the
R have high blood pressure
R have had a cancer affecting your blood
(including leukaemia) which is now in
R are on long-term steroid therapy
R have ever had a previous ectopic
pregnancy (pregnancy outside the womb)
R have a history of fluid filled sacks in the
ovary (ovarian cysts)
R are having Mirena fitted for contraception
or heavy menstrual bleeding and have had
a stroke or heart attack, or if you have any
R disease of your arteries (arterial disease)
R have a history of blood clots (thrombosis)
R are diabetic, as Mirena may affect glucose
You may still be able to use Mirena if you
have or have had some of these conditions.
Your doctor or nurse will advise you.
You must also tell your doctor or nurse if any
of these conditions occur for the first time
while you have Mirena in place.
You must see a doctor or nurse as soon as
possible if you develop painful swelling in
your leg, sudden chest pain or difficulty
breathing as these may be a sign of a blood
clot. It is important that any blood clots are
You must also see a doctor without delay
if you develop persistent lower abdominal
pain, fever, pain during sexual intercourse
or abnormal bleeding. If you get severe
pain or fever shortly after Mirena has been
inserted, you may have a severe infection
which must be treated immediately.
It is advisable to give up smoking when using
hormone containing products such as Mirena.
Can I change my mind?
Your doctor or nurse can remove Mirena at
any time. Unless you wish to get pregnant
the removal should be carried out during
the first 7 days of your period. Otherwise it is
important to use another form of
contraception (e.g. condoms) in the 7 days
leading up to the removal as intercourse
during this week could lead to pregnancy
after Mirena is removed.
If you do wish Mirena to be removed so
that you can get pregnant your usual level
of fertility is expected to return after it is
removed. Studies have suggested that in
women who discontinue Mirena (in order
to become pregnant) the pregnancy rate at
one year is similar to those who do not use
Taking other medicines
The effect of hormonal contraceptives such
as Mirena may be reduced by medicines that
increase the amounts of enzymes made by
the liver. Please tell your doctor or nurse if
you are taking any:
R medicines used to treat epilepsy
R antifungal medicines (e.g. griseofulvin,
fluconazole, itraconazole, ketoconazole,
R certain antibiotics (rifampicin &
macrolides (e.g. clarithromycin,
R medicines used to treat HIV and Hepatitis
C Virus infections (so-called protease
inhibitors and non-nucleoside reverse
R certain sedatives (called barbiturates)
R medicines used to treat chest pain
(angina) and/or high blood pressure
R products containing St John’s Wort (a
Please tell your doctor or nurse if you are
taking or have recently taken any other
medicines, including medicines obtained
Pregnancy and breastfeeding
Mirena should not be used during
pregnancy or if you think you are
It is very rare for women to become pregnant
with Mirena in place.
Missing a period may not mean that you
are pregnant as some women may not have
periods at all while using Mirena. However, in
order to exclude the possibility of pregnancy,
you should consider a pregnancy test if you
have not had a period for 6 weeks. If this
test is negative there is no need to carry out
another test, unless you have other signs of
pregnancy, e.g. sickness, tiredness or breast
If you do become pregnant with Mirena in
place, please contact your doctor as soon as
possible so that ectopic pregnancy can be
excluded and Mirena removed to reduce the
risk of spontaneous abortion.
Very small amounts of the hormone in
Mirena are found in breast milk but the levels
are lower than with any other hormonal
contraceptive method. Please ask your doctor
or nurse for advice before breastfeeding.
3. How and when Mirena is used
Only a doctor or specially trained nurse can fit
Mirena. They will explain the fitting procedure
and any risks associated with its usage. You
will then be examined by your doctor or
nurse before Mirena is fitted. If you have any
concerns over its usage you should discuss it
When Mirena is fitted for contraception or
heavy menstrual bleeding:
Mirena should be inserted either during
your period or within seven days from the
beginning of your period. If you already
have Mirena and it is time to replace it with
a new one, you do not need to wait until
your period. If you have just had a baby,
you should wait at least 6 weeks before
having Mirena fitted (see section 4 “Possible
side effects – Severe pain and continued
bleeding”). Mirena can sometimes be fitted
immediately after you have had an abortion,
provided that you have no genital infections.
When Mirena is fitted for HRT use:
If you no longer have periods then Mirena
can be inserted at any time. If you still have
periods, Mirena should be inserted during the
last days of bleeding.
Remind your healthcare provider that you
have Mirena inserted, especially if they were
not the person who inserted it.
How quickly does Mirena work?
You are protected from pregnancy as soon as
Mirena is fitted. The possibility of becoming
pregnant is approximately 2 in 1,000 in the
first year. The failure rate may increase in
case of the Mirena coming out by itself (see
page 12) or perforation (see page 14 ‘Side
Heavy menstrual bleeding:
Mirena usually results in lighter periods after
3 to 6 months of treatment.
The hormone in Mirena will begin to protect
the lining of your womb as soon as it is fitted.
How often should I have Mirena checked?
You should have it checked 6 weeks after it is
fitted. Your doctor may determine how often
and what kind of check-ups are required in
your particular case.
How can I tell whether Mirena is in place?
Gently put a finger into your vagina and feel
for the two thin threads attached to the lower
end of Mirena. Your doctor or nurse will show
you how to do this.
Do not pull the threads because you may
accidentally pull it out. If you cannot feel
the threads, contact your doctor or nurse as
soon as possible and in the meantime avoid
intercourse or use a barrier contraceptive
(such as condoms). The threads may have
simply drawn up into the womb or cervical
canal. If the threads still cannot be found by
your doctor or nurse, they may have broken
off, or Mirena may have come out by itself, or
in rare cases it may have perforated the wall
of your womb (uterine perforation, see section
4). It may be necessary for you to have an
ultrasound scan or x-ray to locate Mirena.
Contact your doctor or nurse if you can feel
the lower end of Mirena itself or you or your
partner feel pain or discomfort during sexual
What happens if Mirena comes out by
If it comes out either completely or partially
you may not be protected against pregnancy.
It is rare but possible for this to happen
without you noticing during your menstrual
period. An unusual increase in the amount of
bleeding during your period might be a sign
that this has happened. Tell your doctor or
nurse if there are any unexpected changes in
your bleeding pattern.
How will Mirena affect my periods?
Mirena will affect your menstrual cycle.
For all uses of Mirena:
You may have lighter periods or painful periods
or some spotting (light bleeding in between
periods) and irregular bleeding during the first
few months after Mirena is fitted.
You may have prolonged or heavy bleeding or
an increase in the frequency of bleeding,
usually in the first 2 to 3 months, before a
reduction in blood loss is achieved.
Overall you are likely to have fewer days
bleeding in each month and you might
eventually have no periods at all. This is due
to the effect of the hormone (levonorgestrel)
on the lining of the womb.
If you have had Mirena fitted for heavy
You should have lighter periods after 3 to 6
months. If you do not have lighter periods
after 3 to 6 months, alternative treatments
should be considered.
If you have had Mirena fitted for HRT use:
If you have had Mirena fitted for quite a
long time and then start to have bleeding
problems, it is important that you contact
your doctor so that tests can be carried out
to exclude changes to your womb.
There is a calendar on the last page of this
patient information booklet. Your doctor or
nurse may ask you to fill this in to check your
pattern of bleeding. If you are asked to do
so, mark the date of insertion with an “×” in
the appropriate date square. Mark days of
spotting with “ ” and bleeding with “ ”.
4. Possible side effects
Taking any medicine carries some risk of side
effects. With Mirena these are most common
during the first months after it is fitted and
decrease as time goes on.
If you experience any of the following
serious side effects please contact your
doctor or nurse immediately:
R Severe pain or fever developing shortly
after insertion may mean that you have
a severe infection which must be treated
immediately. In rare cases very severe
infection (sepsis) can occur.
R Severe pain and continued bleeding as
this might be a sign of damage or tear
in the wall of the womb (perforation).
Perforation is rare, but occurs most often
during the fitting of the Mirena, although
the perforation may not be detected until
sometime later. If this happens the Mirena
will be removed; very rarely this may
require surgery. The risk of perforation is
low, but is increased in breastfeeding
women and in women who have had a
baby up to 36 weeks before insertion.
Possible signs and symptoms of
perforation may include:
P severe pain (like menstrual cramps) or
more pain than expected
P heavy bleeding (after insertion)
P pain or bleeding which continues for
more than a few weeks
P sudden changes in your periods
P pain during sex
P you can no longer feel the Mirena
threads (see section 3 ”How and when
Mirena is used - How can I tell whether
Mirena is in place?”).
R Lower abdominal pain especially if
you also have a fever or have missed a
period or have unexpected bleeding, as
this might be a sign of ectopic pregnancy.
The absolute risk of ectopic pregnancy
in Mirena users is low. However, when a
woman becomes pregnant with Mirena
in place, the relative likelihood of ectopic
pregnancy is increased.
R Lower abdominal pain or experience
painful or difficult sex as this might
be a sign of ovarian cysts or pelvic
inflammatory disease. This is important as
pelvic infections can reduce your chances
of having a baby and can increase the risk
of ectopic pregnancy.
Very Common (more than 1 in 10 women)
R vaginal bleeding including spotting
R absent, light or infrequent menstrual
Common (less than 1 in 10 women)
R ovarian cysts
R painful periods
R weight gain
R depression, nervousness
R abdominal, pelvic or back pain
R increased growth of hair on the face and
R reduced sex drive
R increased vaginal discharge
R inflammation of the vulva and vagina
R tender, painful breasts
R Mirena coming out by itself
Uncommon (less than 1 in 100 women)
R genital infections that may cause: vaginal
itching; pain on passing urine; or lower
abdominal pain from inflammation of the
womb, ovaries or Fallopian tubes
R infection or inflammation of the lining
of the womb, which may cause a foul
smelling vaginal discharge (endometritis)
R inflammation of the neck of the womb
R swelling of your abdomen, legs or ankles
R hair loss
R itchy skin including eczema
R skin discolouration/increased skin pigment
especially on the face (chloasma)
Rare (less than 1 in 1000 women)
R uterine perforation (see ‘serious side
R allergic reaction (symptoms may include
rash, itching or rapid swelling of the face,
mouth, tongue and/or throat)
R increased blood pressure
Your partner may feel the removal threads
Every woman is at risk of breast cancer, but it
is rare in women under the age of 40. Breast
cancer has been reported in Mirena users,
although the risk and frequency are unknown.
In pre-menopausal women, the frequency of
developing breast cancer whilst using Mirena
is possibly similar to that associated with
using Combined Oral Contraceptives, but the
evidence for this is less conclusive.
In post-menopausal women, using hormone
replacement therapy (HRT) slightly increases
the risk of breast cancer. Although the risk
of developing breast cancer is higher with
combined oestrogen/progestogen HRT, than
with oestrogen-only HRT, the risk of breast
cancer developing when Mirena is prescribed
to provide the progestogen component of HRT
is not yet known. The patient information
leaflet of the oestrogen component of the
treatment should also be consulted for
It is important to regularly check your breasts
and you should contact your doctor if you feel
any lump in your breasts. You should also tell
your doctor if a close relative has or ever had
If any of the side effects gets serious, or if
you notice any side effects not listed in this
booklet, please tell your doctor or nurse.
Reporting of side effects
If you get any side effects talk to your doctor,
pharmacist or nurse. This includes any
possible side effects not listed in this leaflet.
You can also report side effects directly (see
details below). By reporting side effects you
can help provide more information on the
safety of this medicine.
Yellow Card Scheme
5. Further Information
What Mirena contains
Mirena contains 52 milligrams of
levonorgestrel. The hormone is contained
within a substance called polydimethylsiloxane. This is surrounded by a membrane
(skin) also made of polydimethylsiloxane.
The Mirena T-shaped frame also contains
barium sulphate so that it can be seen on
What Mirena looks like and contents of
Mirena consists of a small white T-shaped
frame made from a plastic called
polyethylene. There are two fine brown
threads, made of iron oxide and
polyethylene, attached to the bottom of the
frame. These allow easy removal and allow
you or your doctor or nurse to check that
Mirena is in place.
Each sterile pack contains one Mirena and
should not be opened until required.
Product Licence Holder:
400 South Oak Way
PL Number: 00010/0547
Mirena is manufactured by:
Pansiontie 47, 20210 Turku
This booklet was revised November 2017.
Date of insertion = × Spotting =
Source: Medicines and Healthcare Products Regulatory Agency
Disclaimer: Every effort has been made to ensure that the information provided here is accurate, up-to-date and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. This information has been compiled for use by healthcare practitioners and consumers in the United States. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate that the drug or combination is safe, effective or appropriate for any given patient. If you have questions about the substances you are taking, check with your doctor, nurse or pharmacist.