Hormonal Coils (IUS) : A Complete Guide for Perimenopause and Menopause
Article written by Dr Emma Ginns, British Menopause Society Registered Specialist, GP, Co-founder of Lemala Health, November 2025. This information is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider for personal guidance.
Hormonal coils (also known as intrauterine systems or IUS) are commonly used in perimenopause and menopause. They can help manage heavy or irregular bleeding, provide contraception, and form part of hormone replacement therapy (HRT).
This guide explains how they work, when they are used as part of HRT, and the benefits and risks to consider.
What Is a Hormonal Coil (IUS)?
A hormonal coil is a small, flexible T-shaped device placed into the womb. It releases a steady dose of levonorgestrel, a well-established synthetic progestogen.
Once fitted, the coil sits inside the womb and releases hormone locally. It has two soft threads at the top of the vagina to allow for checking and removal.
Which hormonal coils are used in the UK?
Common hormonal coils include:
Mirena
Levosert
Benilexa
Jaydess
Kyleena
The higher-dose coils, Mirena, Levosert and Benilexa, are suitable for protecting the womb lining as part of HRT and for managing heavy periods.
Lower-dose coils, such as Jaydess and Kyleena, are not suitable for HRT or for treating heavy bleeding.
How does a hormonal coil work?
The coil releases progestogen directly into the womb.
This keeps the womb lining thin and stable, which:
Reduces bleeding
Prevents over-thickening of the lining
Protects against endometrial cancer when using oestrogen
Because the hormone works mainly locally, most women experience fewer whole-body side effects compared with oral progesterone.
Using a hormonal coil as part of HRT
If you are taking oestrogen and still have a womb, you need progesterone to protect the womb lining.
A higher-dose hormonal coil can provide this protection for five years.
This means it can:
Replace daily progesterone tablets
Reduce unscheduled bleeding on HRT
Provide a steady, consistent hormone effect
For many women, this makes the hormonal coil one of the simplest and best-tolerated ways to take the progesterone part of HRT.
Hormonal coil for heavy periods in perimenopause
Heavy or unpredictable bleeding is very common during perimenopause.
Some women experience:
Flooding
Large clots
Long or frequent periods
A hormonal coil can significantly reduce bleeding and, for many women, periods stop altogether.
It is also often helpful in conditions such as adenomyosis or endometriosis.
Hormonal coil for contraception in your 40s and 50s
Hormonal coils are one of the most effective long-acting contraceptive options.
This is important because HRT does not provide contraception.
Higher-dose coils can be used:
For up to eight years for contraception
Until age 55 if fitted at age 45 or older
The hormonal coil is the only HRT-compatible option that provides both contraception and womb lining protection.
What are the benefits of a hormonal coil?
Highly effective contraception
Reliable protection of the womb lining with HRT
Can reduce or stop heavy periods
Lower levels of hormone in the bloodstream
Long-lasting and low maintenance
Cost-effective over time
Helpful for managing perimenopausal bleeding
Suitable for women who cannot tolerate oral progesterone
What are the possible side effects?
Side effects are usually mild and often settle within three to six months.
They may include:
Breast tenderness
Acne
Headaches
PMS-type symptoms
Irregular bleeding or spotting
Occasional mood changes
What are the risks of a hormonal coil?
Insertion can be uncomfortable, particularly if you have not had a vaginal birth or if the cervix is narrow.
Rare risks include:
Perforation of the womb wall, around 2 in 1000 insertions
The coil moving or coming out
Infection in the first few weeks after fitting
Pregnancy is very rare, but if it occurs there is a slightly higher chance of it being ectopic. Any positive pregnancy test should be assessed urgently.
Who might a hormonal coil be suitable for?
A hormonal coil may be a good option if you are:
Experiencing heavy or irregular bleeding
Using or considering HRT
Looking for reliable contraception
Sensitive to oral progesterone
Wanting a low-maintenance option
A menopause specialist can help you decide if it is the right choice based on your symptoms and medical history.
Advantages and disadvantages of hormonal coils
Advantages
Effective contraception
Supports HRT safely
Reduces heavy bleeding
Long-lasting
Convenient
Disadvantages
Insertion can be uncomfortable
Irregular bleeding is common at first
Small risks of expulsion, perforation or infection
Not suitable for some uterine conditions
Some women experience hormonal side effects
Common questions about hormonal coils:
-
No. Levonorgestrel is a synthetic progestogen, designed to mimic the natural effects of progesterone.
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Higher-dose coils (Mirena, Levosert, Benilexa) can be used for:
Up to eight years for contraception
Up until age 55 if fitted at age 45 or later (current UK guidance)
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Higher-dose coils provide endometrial protection for five years.
After this, you can:
Replace the coil
Or leave it for contraception and use another form of progesterone for HRT
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Most removals are quick and straightforward.
A speculum is inserted, the threads are gently pulled, and the coil slides out easily.
If threads are not visible, removal may require additional steps or a scan.