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How the menstrual cycle impacts your immune system

By Bonnie Azoulay, Contributing writer

Some of the tell-tale signs of menstruation include cramping and bloating — but there’s much more to it than that. Yes, the menstrual cycle affects your body, but it also affects your immune system too.

Your cycle and your immune system

Women may experience a cold, cough, throat ache, or other flu-like symptoms before their period. Sex hormone fluctuations, in part, are to blame for why you may be feeling crummy. 

According to a 2018 study published in The Autoimmune Journal, these drastic changes to progesterone and estrogen before menstruation can affect your immunity before and during your period. Plus, as you experience more inflammation (AKA cramping and bloating), your immune cells might be lower. As a result, it will be harder for your lower immune system to fight off a virus or bacteria that’s already brewing. Additionally, because your menstrual cycle affects your circadian rhythm (the natural process that regulates sleep patterns, hunger cues, hormone release, and period), this can also throw off your immune system. When your circadian rhythm is disrupted, your health may suffer as a result. 

For more about how the four phases of your period cycle affect your immune system and how to manage your health, read below. 

Changes in the immune system

Menstruation Phase

With a rise in estrogen and a drop in progesterone, your immune system will decrease and inflammation will increase. 

Follicular Phase

As your body prepares for an egg release, levels of estrogen will increase to thicken the uterus lining for a possible pregnancy. Your immune system will be stronger, thanks to the increase in estrogen. In general, women have higher immunity than men because of how estrogen impacts their bodies. However, estrogen can also pose the opposite effect on the immune system and cause women with high levels of estrogen to become more prone to autoimmune disorders.

Ovulation Phase

Estrogen levels and your immune system decrease to accommodate the possibility of sperm entering your body for a possible pregnancy, according to research from the Journal of Leukocyte Biology. But at the same time, it allows bacteria and viruses to attack the body. 

Luteal Phase

Progesterone rises and peaks to prepare for your period when a pregnancy doesn’t occur. As a result, your immune system may decrease. According to a 2017 study in Mucosal Immunology, progesterone can lower the ability to fight infections. 

How to boost your immune system

According to Harvard Health Publishing, you can strengthen your immunity by eating a diet high in fruits and vegetables, not smoking, washing your hands, getting adequate sleep, and trying to minimize stress. “Healthy immune system warriors need good, regular nourishment,” they state. So, if you don’t like eating fruits and vegetables,taking a daily multivitamin and mineral supplement can strengthen your immune system too. 

Reviewed by the Ovia Health Clinical Team

Read more


  • Sabine, Oertelt-Prigione. “Immunology and the menstrual cycle.” The Autoimmune Journal. (6-7): A486-92. Web. May 2012. 
  • Khan, Deena. “The Immune System Is a Natural Target for Estrogen Action: Opposing Effects of Estrogen in Two Prototypical Autoimmune Diseases.” Frontiers in Immunology. 10.3389/fimmu.2015.00635. Web. January 2016. 
  • Williams, Sarah. “Why Women Are More Prone to Infections When Ovulating.” Live Science. May 30, 2013. https://www.livescience.com/36067-women-prone-infections-ovulating.html
  • Hall, O., Klein. “Progesterone-based compounds affect immune responses and susceptibility to infections at diverse mucosal sites.” Mucosal Immunology. 10, 1097–1107. Web. April 2017. 
  • “How to boost your immune system.” Harvard Health Publishing. February 15, 2021. https://www.health.harvard.edu/staying-healthy/how-to-boost-your-immune-system

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