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, which is inserted under the skin, and 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?


What are the side effects?

The side effects of Etonogestrel are reported separately for the hormonal implant and the vaginal ring. 

Common side effects affecting people using the hormonal implant1 are:

Common side effects affecting people using the Vaginal Ring (reported by the manufacturer*) are:

*The NuvaRing has historically not been available on prescription in some local health authorities, and the NICE British National Formulary (a collection of guidance for the prescription of medicines) does not collect information on side effects of the vaginal ring. 


  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]

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