Mirena
What is Mirena and how does it work?
Mirena is a small, T-shaped intrauterine device (IUD) that is placed inside the uterus to slowly release a low dose of levonorgestrel, a hormone similar to progesterone, directly into the uterus.
Because the hormone acts mainly within the uterus, only a small amount is absorbed into the bloodstream compared with other hormonal contraceptive methods, such as the oral contraceptive pill.
Mirena is commonly used for contraception, to treat heavy or painful menstrual bleeding, or for both.
How does Mirena work?
Mirena works in several ways to prevent pregnancy and reduce menstrual bleeding.
It:
- thickens the mucus at the cervix, making it more difficult for sperm to enter the uterus
- thins the lining of the uterus, resulting in lighter menstrual bleeding and, for many women, no periods at all
Is Mirena right for me?
Mirena is suitable for many women, including teenagers, women who have not had children and women approaching menopause.
It may be recommended if you are looking for:
- highly effective long-term contraception
- treatment for heavy menstrual bleeding
- treatment for painful periods
- endometrial protection as part of hormone therapy.
Mirena may not be appropriate if you have:
- a current pelvic infection
- unexplained vaginal bleeding
- certain abnormalities of the uterus
- particular types of breast cancer
- severe liver disease
- an allergy to any of its components.
Your clinician will discuss your medical history to determine whether Mirena is an appropriate option for you.
If you’re under 18
You can have a confidential discussion with your clinician about contraception and whether Mirena is suitable for you.
Depending on your age and circumstances, your clinician may recommend involving a parent, guardian or another trusted support person. This is intended to ensure you have appropriate support and information, rather than requiring permission in every situation.
Getting ready for your appointment
A small amount of preparation can help make your appointment more comfortable.
Before your procedure:
- your clinician will usually confirm that you are not pregnant
- timing the insertion around your menstrual period may be recommended, although this is not always necessary
- let your clinician know if you have recently had sexually transmitted infection (STI) screening or if you would like this arranged beforehand
- taking simple pain relief, such as paracetamol or ibuprofen, approximately one hour before the appointment may help reduce cramping
- consider eating beforehand and arranging for someone to drive you home if you have previously felt faint during medical procedures
- bring a sanitary pad, as light bleeding or spotting afterwards is common.
What happens during the insertion
The Mirena may be inserted during a consultation or, depending on your circumstance, under an anaesthetic or sedation. The appointment usually takes around 15 to 20 minutes, although the insertion itself is only a few minutes.
During the procedure:
- you will lie on an examination couch in a similar position to a cervical screening test
- a speculum is gently inserted to allow the cervix to be seen clearly
- the uterus is measured and, if required, the cervix is cleaned and local anaesthetic may be offered
- Mirena is inserted through a thin tube into the uterus
- the insertion tube is removed, leaving the device in place
- two fine threads remain at the top of the vagina to allow your clinician to check the position of the device and remove it when required.
Most women experience cramping similar to menstrual pain during insertion. This is usually short-lived, although the intensity varies from person to person.
Pain relief options
Several pain relief options are available and should be discussed with your clinician before the procedure.
These may include:
- paracetamol or ibuprofen before the appointment
- local anaesthetic to the cervix
- additional local anaesthetic techniques where appropriate
- sedation in selected situations, such as previous difficult insertions or significant procedural anxiety.
Your clinician will discuss the most appropriate option for your circumstances.
Right after the procedure
Most women return home shortly after the procedure and are able to resume their normal activities later the same day, although many choose to rest for the remainder of the day.
It is normal to experience:
- cramping similar to menstrual pain
- light bleeding or spotting
- occasional light-headedness immediately after insertion.
For approximately one week, you should avoid:
- tampons
- menstrual cups
- swimming pools
- baths
- penetrative sexual intercourse.
These precautions help reduce the risk of infection while the cervix heals.
What's normal in the weeks and months after
Your body needs time to adjust to Mirena. Bleeding patterns are the biggest change most people notice, and they typically settle over three to six months.
This is usually normal | Get in touch with us |
|---|---|
Irregular spotting or light bleeding for the first 3–6 months | Heavy bleeding that soaks a pad every hour or two |
Periods becoming lighter, shorter, or stopping altogether over time | Fever, chills, or feeling generally unwell |
Mild cramping on and off in the first few months | Severe or worsening pelvic pain |
Some breast tenderness, mood changes, or headaches early on, usually settling | Pain or bleeding during sex that’s new or worsening |
Feeling the threads with clean fingers, but not the device itself | You can’t feel the threads, or you can feel the hard plastic device |
Any signs you might be pregnant | |
Unusual vaginal discharge with an odour |
When to seek help urgently
Contact your clinic promptly, or present to an emergency department, if you experience:
- Severe abdominal or pelvic pain, especially with fever
- Heavy bleeding that’s unusual for you
- Signs of pregnancy while Mirena is in place — this needs prompt review to rule out a rare but serious ectopic pregnancy
- Sudden inability to feel the threads, or feeling the device has shifted or come out
Follow-up
Your clinician will usually arrange a follow-up appointment approximately six weeks after insertion to confirm that the Mirena remains correctly positioned.
After this, Mirena requires very little ongoing maintenance. Some women choose to check the threads themselves occasionally, while others prefer their clinician to do this during routine examinations.
How long does it last, and what about removal?
Mirena is approved in Australia for up to eight years, depending on the reason it is being used.
It can be removed at any time if you wish to become pregnant or choose another form of contraception.
Removal is usually quicker and more comfortable than insertion.
Following removal, fertility generally returns quickly, and most women resume their normal menstrual cycle within a short period.
Common questions
Will Mirena affect my future fertility?
No. Mirena doesn’t affect your long-term fertility. Once it’s removed, your natural cycle and the ability to conceive typically return within a short time.
Can I use Mirena if I haven't had children?
Yes. Mirena is suitable and commonly used by patients who haven’t been pregnant before.
Will my partner feel it during sex?
Occasionally a partner may feel the threads, particularly soon after insertion. If this is bothersome, your clinician can trim them further.
What if I want to fall pregnant sooner than expected?
Mirena can be removed whenever you choose. There is no need to wait until the end of its lifespan or for a particular stage of your menstrual cycle.
Does insertion hurt more if I haven't given birth vaginally?
Some women who have not had a vaginal birth find insertion more uncomfortable. If you are concerned, discuss pain relief options with your clinician before your appointment.
What to remember
Mirena is one of the most effective long-term contraceptive options available and is also an effective treatment for heavy or painful menstrual bleeding.
Although insertion can cause temporary discomfort, the procedure is brief and most women recover quickly. Your clinician will discuss whether Mirena is the right option for your individual circumstances and help you choose the most appropriate pain relief and follow-up plan.
Further Information
This information provides general guidance and does not replace individual medical advice. If you have questions about whether Mirena is suitable for you, discuss them with your GP or gynaecologist.
This article is intended for educational purposes only and should not replace personalised medical advice, diagnosis or treatment. Every article is written by a qualified specialist clinician and independently reviewed by a second specialist clinician to help ensure clinical accuracy and reflect current evidence-based practice.
