How does it work?The progestogen only pill containing norethisterone works by thickening the cervical fluid which can prevent sperm from entering your uterus, and by thinning the lining of your uterus preventing a fertilised egg from implanting. When used in the combined pill alongside oestrogen they also prevent ovulation.
What is it used in?Combined Pill
Is it androgenic?Yes.2 (Check out our ‘Androgens’ blog for more info on what this means).
What are the side effects?Norethisterone’s side effects vary depending on how it is taken. When it’s taken alongside other hormones, such as in the combined pill, it’s impossible to say which side effects are due to norethisterone alone. The following side effects have been recorded with oral use of norethisterone3:
- Menstrual cycle irregularities
- Mood changes
- Breast tenderness
- Weight change
- Kim JJ, Kurita T, Bulun SE. Progesterone action in endometrial cancer, endometriosis, uterine fibroids, and breast cancer. Endocrinology Review. 2013. 34(1):130-162. Available from: doi:10.1210/er.2012-1043
- Graham CA. The pill and women’s sexuality. BMJ. 2019. 364 Available from: doi: https://doi.org/10.1136/bmj.l335
- Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press <https://bnf.nice.org.uk/drug/norethisterone.html> [13 August 2020]