What is Nomegestrol Acetate?
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What's the lowdown?
Nomegestrol acetate is a synthetic progesterone used in oral contraception or hormonal replacement therapy
Nomegestrol acetate in combination with ethinyl estradiol is sold under the brand name ZoelyÂ
Prolonged use of nomegestrol acetate has been linked to an increased risk of developing intracranial meningiomas
Nomegestrol acetate has mild androgenic effects on the body
Nomegestrol acetate is a synthetic progestin that was first licensed for use in 2011. It’s also used in some hormonal therapies for menopausal women.
It is used in the combined pill alongside ethinyl estradiol, a synthetic oestrogen, and taken orally. It has a half-life of around 50 hours.
How does Nomegestrol Acetate work?
Nomegestrol acetate prevents ovulation by suppressing lutenising hormone1. When combined with the oestrogen ethinyl estradiol it can also thicken the cervical fluid to stop sperm from entering your uterus, and can thin the lining of your womb so that a fertilised egg can’t implant.  If taken correctly, it is 99% effective in preventing pregnancy.
What is it in?
Combined pill
- Zoely
Is Nomegestrol Acetate androgenic?
No – in fact, it is mildly anti-androgenic1. (Check out our ‘Androgens’ blog for more info on what this means).
Nomegestrol Acetate side effects
The following side effects have been reported for nomegestrol acetate2:
- Unusual menstrual bleeding
- Absence of a withdrawal bleed
- Acne
- Weight change
- Mood changes
- Headaches/Migraines
- Loss of libido
- Nausea
- Breast tenderness
- Pelvic pain
Data taken from self reported Lowdown Zoely user reviews in September 2024 shows that 31% experienced period-like cramps, 19% felt nauseous, 44% had lighter periods, and 31% noticed a positive change in mood. 63% reported no effect on sex drive, 75% mentioned no impact on weight and 56% said it had no impact on their skin.
Meningioma risk
There has been some research showing that nomegestrol acetate increases the risk of developing intracranial meningiomas. This is a benign (non-cancerous) brain or spinal cord tumour that can grow slowly oftentimes not causing symptoms. It is recommended that women who used nomegestrol acetate should be advised of these risks and regularly screened for meningiomas3.
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Our medical review process
This article has been medically reviewed for factual and up to date information by a Lowdown doctor.
