Can I get the COVID-19 vaccine while I am menstruating (having my period)? Will it affect my cycle? Will it make my period heavier?

Question: 

Can I get the COVID-19 vaccine while I am menstruating (having my period)? Will it affect my cycle? Will it make my period heavier?

Answer: 
People do not need to schedule their COVID-19 vaccine around their menstrual cycle. There are no issues with getting the vaccine during your period.
 
The immune system is not sufficiently affected by either the COVID-19 vaccine or the menstrual cycle, so scheduling around them is not necessary. In fact, delaying vaccination around your cycle may only leave you unprotected from COVID-19 for a longer time without providing any known benefit.
 
Menstruation is a complex process, and can be influenced by many things, such as environmental changes, stress, sleep and some medications. The lining of the uterus is in fact considered to be an active part of the immune system. When your immune system is working hard because you’re vaccinated or sick, you may experience changes in how the endometrium reacts. In this way it is possible that the vaccine affects menstruation somehow.
 
But, one thing to keep in mind is that anytime you look at a large group of people, there will always be some people experiencing changes in their menstrual cycle. For example, if you looked at a million people who drank water today, there will be some people who experienced changes in their menstrual cycle. That doesn’t mean that drinking water causes changes in the menstrual cycle - it’s just what happens when you look at a large number of people. With hundreds of millions of vaccines being given worldwide, there will be some people who experience changes in their menstrual cycle too. The key is to figure out whether the vaccine causes it, and whether it is something to be concerned about. Researchers are confident that the vaccine is safe, and that there is not enough data to suggest that there should be concerns over potential changes to the menstrual cycle. In addition, medical experts continue to assert that the COVID-19 vaccine does not impact fertility. The COVID-19 vaccine is not shed after vaccination, so being around recently vaccinated individuals would not be expected to affect someone’s cycle either.
 
The good news is that any changes you experience in your menstrual cycle after getting the vaccine are temporary, so it shouldn’t be a reason not to get a shot. However, women with concerns should speak with their doctor since cycles can be delayed for other reasons as well. 
Date last reviewed: 
Thursday, Apr 29, 2021