Nomegestrol Acetate

by The Lowdown · May 24, 2021

by Dr Melanie Davis-Hall · May 24, 2021

Nomegestrol acetate is used in the combined pill alongside ethinyl estradiol, a synthetic oestrogen.

Nomegestrol acetate is a synthetic progestin that was first licensed for use in 2011, making it a fairly recent addition to the contraceptive world. It’s also used in some hormonal therapies for menopausal women.

It is used in the combined pill alongside ethinyl estradiol, a synthetic oestrogen.

How does it 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.

What is it in?

Combined pill

  • Zoely

Is it androgenic?

No – in fact, it is mildly anti-androgenic1. (Check out our ‘Androgens’ blog for more info on what this means).

What are the side effects?

The following side effects have been reported for nomegestrol acetate3:

  • Unusual bleeding
  • Absence of a withdrawal bleed
  • Acne
  • Weight change

Please note as it’s such a new pill there is a lack of research evidence for Zoely, so The National Institute for Health and Care Excellence (NICE) advises that the side effects that are common in combined contraceptive pills in general should also be considered potential side effects of Zoely. To learn more about other combine contraceptive pills visit the contraception pages on The Lowdown website. 

  1. Ruan X and others. The pharmacology of nomegestrol acetate, Maturitas. 2012. Volume 71. 4: 345-353. Available from:
  2. NICE. Combined oral contraception: nomegestrol/estradiol (Zoely), Evidence summary [ESNM28] Published date: 17 December 2013 Available from: <> [Accessed 13 August 2020]