Of the hormonal coils, the Mirena coil is licensed to be used in those with heavy periods. In this article, we will lay out the problem of heavy bleeding, how Mirena can help to deal with this and a few other questions that patients often have.
Many women find that during their period, they suffer from symptoms such as discomfort, cramping, and an irregular or very heavy flow. Some signs and symptoms that you may notice are soaking one or more sanitary pads or tampons, or if a pad or tampon needs to be changed every hour to prevent any bleeding onto clothes. If you find yourself using double sanitary protection to control the menstrual flow, or you must wake up through the night to check or change the sanitary protection, then you may suffer from a heavy period.
The medical terminology for heavy periods is menorrhagia which means heavy periods that occur each month. You may also have a heavy period if your normal period lasts more than 7 days. Chronic (long) or heavy periods might cause health complications such as iron-deficiency anaemia because menorrhagia (prolonged bleeding) reduces the number of red blood cells that are circulating within your body. You may feel a lack of energy, be experiencing symptoms such as pale skin, fatigue, tiredness, and dizziness. Although diet plays a role in iron deficiency anaemia, heavy menstrual periods compound the problem. Along with heavy menstrual bleeding, you may experience painful menstrual cramps (dysmenorrhea) that can be severe in some cases and therefore they require medical attention.
You may notice that your menstrual cycle is restricting you from your daily life activities, like taking time off work or going out with friends – these can also be signs of a heavy period.
There are many options for managing heavy periods including medication, hormonal contraceptives, intrauterine system (IUS) and surgery. Choosing what kind of treatment is the best option for you depends on whether you are planning to become pregnant. You can try medication to reduce the amount of bleeding and painkillers to help ease the menstrual cramps. The hormonal contraceptives (when used for treatment of heavy periods), and intrauterine system (IUS) such as Mirena coil, reduce the heavy bleeding by thinning the lining of the womb (endometrium). If the woman has decided she no longer wants to get pregnant, surgical options are available too.
One surgical option is endometrial resection or ablation, where the lining of the womb is removed using surgical techniques. Another, major, surgical option known as a hysterectomy, is when the womb is removed entirely.
The hormonal contraceptives will have a temporary effect on your menstrual cycle, while the surgery, which consists of removing the womb (hysterectomy), and removing the lining of the womb (endometrial) will have a permanent effect. If heavy periods are not causing anaemia, a woman can choose not to have any treatment at all.
Based on the comparison of the treatment options, the intrauterine systems (IUSs) are most effective at reducing the bleeding and the symptoms of the heavy period. They affect the menstrual cycle whilst they remain inside of your uterus and they are not limiting the option to the woman of getting pregnant after the removal of the Mirena coil. Surgical options like hysterectomy and endometrial ablation are also effective, but they may have some major side effects and they reduce the ability of having a child permanently.
In a clinical trial of Mirena coil in women with heavy periods the majority experienced an 80% reduction in bleeding after 3 months, and >90% reduction in bleeding after 6 months. Mirena coil is an effective nonsurgical treatment for managing both: prolonged periods and painful periods. In one study, 41 women were taken off the surgery list for removing the uterus or having resection of the endometrium because of the successful therapy provided by the Mirena.
In another study, which evaluated efficacy and performance up to 1 year of using the Mirena was shown to be an effective treatment for prolonged periods in three out of four women. It was concluded that Mirena can be used as an alternative therapy for women that can not have surgery as an option, because of medical reasons.
Scientists compared the three therapy treatments for heavy periods: Mirena, surgical removal of the uterus, and endometrial ablation in a decision analysis model. They evaluated complications, mortality, and treatment outcomes over a 5-year period in these three methods and concluded that Mirena coil is the best treatment based on quality-adjusted life years score (QALYs).
Levonorgestrel intrauterine system (Mirena): An emerging tool for conservative treatment of abnormal uterine bleeding
They investigated the efficacy of levonorgestrel intrauterine system (hormonal coil; Mirena) in conservative management of abnormal menstrual bleeding. Seventy women between 30 and 55 years with symptoms of heavy periods were included in the research study that was conducted over a period of 3 years. The study concluded that Mirena coil is effective in the treatment for menorrhagia (heavy menstrual bleeding).
The levonorgestrel intrauterine system in the management of menorrhagia
This research study was obtained in a general hospital in South Wales. The objective was to measure the effect of the hormonal coil in the management of heavy periods. The hormonal coil was used to treat fifty women who had failed medical therapy and were waiting for surgical treatment like hysterectomy (removal of uterus) or transcervical endometrial resection (endometrial resection). They concluded that the hormonal coil is an effective treatment for heavy and painful periods.
Therapeutic use of levonorgestrel-releasing intrauterine system in women with menorrhagia: a pilot study
In this descriptive, prospective and non-comparative the researchers were also assessing the efficacy and performance of an hormonal coil releasing 20 μg/day of hormonal coil (Mirena) in the treatment of women with prolonged menstrual periods. At the end of the study, it was concluded that the hormonal coil was an effective treatment for three out of four women with menorrhagia (heavy menstrual bleeding).
Comparison of the levonorgestrel-releasing intrauterine system, hysterectomy, and endometrial ablation for heavy menstrual bleeding in a decision analysis model
The goal of this study was to estimate clinical outcomes after the placement of a hormonal coil, resection of endometrial tissue with laser, or surgical removal of uterus in patients with heavy periods with dominant symptoms of heavy bleeding. Their decision analysis model, concluded that using hormonal coil or having a surgical procedure for removal of womb is a better solution for treating heavy menstrual bleeding, that the resection of endometrial tissue with laser.
Levonorgestrel-releasing intrauterine system and endometrial ablation in heavy menstrual bleeding: a systematic review and meta-analysis
In this study, they compared the effects of the hormonal coil and the surgical procedure resection of endometrial tissue. By taking in account: menstrual blood loss, failure rate, quality of life, and adverse events, this study compared the efficacy and safety of the hormonal coil and the surgical procedure resection of endometrium for the treatment of heavy menstrual bleeding. They concluded that these two treatments had similar positive effects on heavy menstrual bleeding up to two years of treatment.
How common are the heavy periods among women?
Heavy periods are common in women, and usually, they may be a normal incidence. Studies show that heavy periods affect 9 to 14 out of every 100 women. Prolonged menstrual bleeding occurs when a period lasts more than five to seven days. According to NICE guidelines about 1 in 20 women aged between 30 and 49 years consult their GP each year because of heavy periods or menstrual problems, and menstrual disorders comprise 12% of all referrals to gynaecology services.
How are heavy periods diagnosed?
We will ask you about your medical history and menstrual cycles. Tests can be conducted to establish the diagnosis and to identify the underlying cause. For example, you may be offered a blood test to see if you suffer from iron-deficiency anaemia, a smear test, an endometrial biopsy, an ultrasound, or a hysteroscopy.
What causes heavy periods?
In most cases the underlying cause for heavy periods can be hard to identify. When there is an unknown cause, this condition is called idiopathic menorrhagia. This is the most common scenario. Other causes that are less common are conditions affecting your womb, ovaries or hormones, such as polycystic ovary syndrome, fibroids, endometriosis and pelvic inflammatory disease.
How do I know if the Mirena/Hormonal coil is right for my heavy periods?
Mirena coil can be used as a treatment for women experiencing heavy periods who also want contraception for up to five years.
To determine if an intrauterine system (IUS) such as Mirena Coil is the right contraception for you, a clinician will ask about your medical history. The IUS may not be suitable if you have breast cancer or have had it in the past 5 years, cervical cancer or womb (uterus) carcinoma, liver disease, unexplained bleeding between periods or after sexual activity, arterial disease or a history of serious heart disease or stroke, an untreated sexually transmitted infection (STI) or pelvic infection, or if you have had problems with your womb or cervix.
You can use Mirena coil after giving a birth (vaginal or caesarean). You'll have to use another contraception method until the IUS is inserted. In some circumstances, an IUS can be fitted within 48 hours of giving birth. When you are breastfeeding, an IUS is safe and will not affect your milk supply.
If you are 45 or older, and you wish to have the IUS installed, you can keep it until you hit menopause or no longer need contraception.
Mechanism of action of Mirena coil in the treatment of heavy periods
Mirena it's similar to an intrauterine device (IUD), except that the intrauterine system releases the hormone progestogen into the womb instead of copper.
A Mirena coil is a hormone-releasing T-shaped IUS that is made of soft and flexible plastic. It contains the hormone levonorgestrel, which is a form of progesterone stored in a reservoir. At the end of the coil, there is a thin thread that travels out through the cervix which allows for monthly self checks and easy removal. Mirena measurements are 32 mm (Length) x 32 mm (Width).
Mirena works in the way that it releases the hormone steadily, giving you a continuous dose of the hormone over a 5-year period. Mirena works by slowly releasing the hormone levonorgestrel into the womb to treat excessive monthly bleeding. The hormone is affecting the growth of the lining of the womb by thinning it, which results in a reduction in the volume and duration of menstrual bleeding. This is the mechanism of action in the treatment of heavy and prolonged bleeding (menorrhagia).
The Mirena coil is placed in the uterus and can be fitted by our clinicians in Clarewell clinics. The placement represents a non-surgical procedure and Mirena can be placed during an in-office visit or 28 days after giving a birth. Our experienced clinicians will educate you and demonstrate how to complete a monthly self-check to ensure that Mirena remains in its correct position. Following the insertion, you may experience a few side effects. However, these will calm down after 3-6 months. If, after this time, you are still experiencing these side effects, or have any concerns, you can book in for a consultation with us.
What is the strength of the Mirena coil?
Mirena coil contains 52 mg of levonorgestrel (LNG) Initially, this hormone is released at a rate of approximately 20 mcg/day. This rate decreases to approximately 10 mcg/day after 5 years and 8 mcg/day after 7 years. For the treatment of heavy periods and heavy menstrual bleeding, it is advised that Mirena should be replaced with a new one by the end of the fifth year if continued contraception is needed. If the bleeding becomes problematic before the end of the licenced period, it is strongly advised to get it replaced sooner to manage the symptoms.
After how long does the Mirena coil start working?
Mirena coil can take approximately a few months to reach its full effect, but 6 months after insertion most women will have only light bleeding and sometimes no bleeding at all. The amount of spotting and bleeding days may increase when you first have it inserted, but then usually decreases in the months that follow.
Bleeding may also be irregular. The total blood loss per cycle slowly decreases with continued use. Mirena reduced menstrual bleeding by 80% after three months of use according to a research study of women who experienced heavy bleeding. The bleeding had been reduced by 90% after six months.
Will there be any changes in the effectiveness and for how long it can be used?
The Mirena coil is licensed for continuous use for 5 years. During the period of 5 years, there are no changes in the effectiveness of Mirena coil. After that, if you wish to continue with the Mirena coil, it needs to be replaced with a new one.
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Page reviewed by Mrs Julie Milsom
Last reviewed date: 12 January 2023
Next review due: 12 January 2026
Whilst this content is written and reviewed by sexual health specialists, it is for general guidance only. It is not intended to replace the advice of your clinician.
References & Further Reading
- NICE: Heavy menstrual bleeding: assessment and management
- NHS: Intrauterine system (IUS)
- NHS:Mirena coil (IUS)
- NHS: The Mirena Intra-Urine System
- InformedHealth.org: What are the treatment options for heavy periods?
- Journal of mid-life health: An emerging tool for conservative treatment of abnormal uterine bleeding
- British journal of obstetrics and gynaecology: The levonorgestrel intrauterine system in the management of menorrhagia
- Centre for Reviews and Dissemination: Levonorgestrel-releasing intrauterine system and endometrial ablation in heavy menstrual bleeding: a systematic review and meta-analysis
- Contraception: Therapeutic use of levonorgestrel-releasing intrauterine system in women with menorrhagia
- International journal of gynaecology and obstetrics: Comparison of the levonorgestrel-releasing intrauterine system, hysterectomy, and endometrial ablation for heavy menstrual bleeding in a decision analysis model