Covid 19 and menstrual health


Many people have recently been in touch to ask about a possible relationship between the COVID 19 pandemic lockdown and/ or vaccination on their menstrual cycle.

In short, yes, it is perfectly possible to experience changes in cycle length, blood loss, period pain, or mood during a stressful time such as the pandemic! But do not worry, these are temporary changes caused by the situation and will return to 'normal' in time (three cycles)... and if they do not, please seek medical advice because they could also be a sign of a menstrual health disorder (that would have ocurred regardless of the pandemic).

In regard to the vaccine- yes, it is also quite likely that you will notice some temporary disruption to your cycle length, bleeding pattern, or premenstrual changes.

This is not a mystery- or a conspiracy- the menstrual cycle is essentially a series of three inflammatory processes, all associated with the immune system- ovulation, spontaneous decidualisation, and menstruation. [See here for an overview-]. When your body is experiencing physical or psychological stress, this alters the levels of circulating 'stress' hormones and increases the proportion of immune cells associated with the menstrual cycle. This causes an increase in systemic inflammation, which can worsen cyclical changes of all kinds and interfere with your biological/ circadian body clock- affecting cycle length.

When you are given any type of vaccine, the needs of the adaptive immune system (used to identify and destroy infections and diseases) are prioritised over those of the innate immune system (used to keep biological systems operating in a healthy state on a daily basis- including the reproductive system). So depending on where you are in your cycle when you recieve the vaccine, you may experience heavier/ lighter bleeding or continuous spotting for a while, longer/ shorter cycle length, more/ fewer premenstrual changes- until your body clock is able to return to a regular cycle. FYI- this will be much harder for those in frontline care work (doctors, nurses, carers, or cleaners) and anyone else who is working in (crazy) shift patterns at the moment. Healthy anti-inflammatory practices in sleep, diet, exercise, and relaxation will all help this happen more quickly...

Don't believe me? Well, a high quality prospective study of the Danish menstruating population has just found 'No association between COVID-19 vaccination and menstrual disorders'... So, don't believe the (anti-vaxx) hype regarding this life-saving vaccine- it does not negatively or permanently affect your fertility, or cause any lasting effects to cycle length, blood loss, period pain or any other cyclical changes...

Too lazy to explain all this to others (I feel you!)- here's a video you can share, instead!

More about menstrual physiology-


Research News Tags: Covid and Research.


  1. Jenny Constantine

    This is fascinating Sally, thanks for posting this! I learnt loads from your post – shocking to think I’ve only fully understood what the physiology of menstruation actually is now, aged 40! You do amazing work 🙂

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.