by The Lowdown · May 24, 2021

by Dr Melanie Davis-Hall · May 24, 2021

Etonogestrel is a third-generation synthetic progestin (a man-made version of progesterone, a hormone found naturally in our bodies).

Etonogestrel is used in the hormonal implant neplanon, which is inserted under the skin, and combined with oestrogen in the vaginal ring, which is a relatively new form of contraception.

Researchers have been exploring the use of etonogestrel as a form of male contraception1, and a hormonal coil containing etonogestrel was trialled in 2015, but was unsuccessful2.

How does it work?

Etonogestrel works in three ways: it prevents ovulation, changes your cervical fluid to stop sperm from entering your uterus, and changes the lining of your uterus so that a fertilised egg can’t implant3.

What is it in?


Vaginal ring

Is it androgenic?

No. (Check out our ‘Androgens’ blog for more info on what this means).

What are the side effects?

The side effects of etonogestrel are reported separately for the hormonal implant and the vaginal ring. To find out more about these visit the contraception pages on The Lowdown website.

Common side effects affecting people using the hormonal implant nexplanon include:1, 5

  • Changes to your periods, including irregular bleeding
  • Headaches
  • Breast tenderness
  • Mood changes
  • Acne
  • Nausea
  • Ovarian cysts
  • Skin reactions
  • Weight changes


Low on pills? Order your contraception through The Lowdown

  1. Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press <> [Accessed on 13 August 2020]

  2. Adis Insight. Drug profile: Etonogestrel-releasing intrauterine system – Merck & Co. 7 October 2015. Available from <> [Accessed on 13 August 2020]

  3. Merck. What is Nexplanon?. Available from <>  [Accessed on 13 August 2020]

  4. Merck. Possible risks and side effects of NuvaRing. Available from <>  [Accessed on 13 August 2020]

  5. Family Planning Association. Contraceptive implant. Nov 2020. Available at