Reports of menstrual disorders and unexpected vaginal bleeding

The MHRA has reviewed reports of menstrual disorders and unexpected vaginal bleeding suspected as adverse reactions to vaccination with the three COVID-19 vaccines currently being used in the UK: Pfizer/BioNTech, COVID-19 Vaccine AstraZeneca and COVID-19 Vaccine Moderna.

These reports have also been reviewed by independent experts of the Commission on Human Medicines’ COVID-19 Vaccines Benefit Risk Expert Working Group and members of its Medicines for Women’s Health Expert Advisory Group.

As with any suspected side effects from the COVID-19 vaccines, including those in relation to menstrual disorders, please continue to report via the Yellow Card scheme.

The MHRA’s rigorous evaluation of reports of suspected side effects of period problems does not support a link between changes to people’s periods and related symptoms and COVID-19 vaccines.

There is no evidence to suggest that COVID-19 vaccines will affect fertility and your ability to have children.

Our advice remains that the benefits of vaccination outweigh the risks for most people. It is vitally important that people come forward for their first and second vaccine doses when invited.

Whilst uncomfortable or distressing, period problems are extremely common. Stressful life events can disrupt with your periods. Changes to the menstrual cycle have also been reported following infection with COVID-19 and in women affected by long-COVID.

If you have changes to your periods that are unusual for you, persist over time, or you have any new vaginal bleeding after the menopause, following COVID-19 vaccination, please contact your doctor.

Last updated: 12 August 2021