Sex and Your Immune System, What’s the Impact?

You’ve probably read about the pros and cons of having sex—especially the pros, including intimacy and pleasure—but how much do you know about sex and your immune system? Is sexual activity a boon or a bust when it comes to how your immune system functions?

As you may have guessed, it’s both a boon and bust, but you have control over the latter, so the plus side appears to be winning. Let’s take a closer look. First, however, some basics.

Health benefits of sexual activity

Male and female immune system responses to sexual activity and the impact of sex hormones on the body are not the same. That said, here are some of the health benefits of sexual activity for both sexes:

  • Lowers blood pressure
  • May improve quality and health of sperm
  • Improves bladder control in women
  • Reduces or blocks pain, including headache and migraine pain in both sexes and menstrual pain in women
  • Lowers the risk of heart attack
  • Enhances physical fitness and performance
  • Boosts sex drive
  • May reduce the risk of developing prostate cancer
  • Improves sleep
  • Helps reduce stress
  • Promotes better memory
  • Improves connection with your partner because of release of the hormone oxytocin

Of course, to prevent the boon from sexual activity you need to practice safe sex at all times. You also should take care of other lifestyle factors, such as following a nutritious diet, getting enough sleep, and exercising regularly that will support and promote a better sexual experience. Now let’s focus on the impact of sexual activity on immune system function.

Sex and your immune system

Research suggests that individuals who engage in frequent sex (one to two times a week) have higher levels of immunoglobulin A, an antibody that is important in preventing illness and is the main defense against human papillomavirus (HPV). However, those who had sex three or more times a week had the same levels of IgA as those who had sex less than once a week.

This suggests that stress may negate the positive effects of sexual activity, so moderation seems to be the key.

This finding then begs the question, Can too much sexual activity make you less likely to fight off infection? At least one study found that males who had more sexual partners had a reduced ability to fight off bacterial infections. However, the study was done using fruit flies, so whether this translates into humans is not certain.

If you and your partner are interested in getting pregnant, then research shows that the more sexual activity a couple engages in, the better chance of conception. This appears to be true even when couples have sex when the woman is not ovulating. According to research conducted at the University of Indiana, “sexual activity may cause the body to promote types of immunity that support conception.”

Did you know sexual activity can have a beneficial effect on the population of microbes that are living in your gut (i.e., your gut microbiome)? For example, in a University of Colorado study of men who have sex with men, the investigators found that their gut microbiome was different from that of men who have sex with women.

According to one of the study’s authors, Brent Palmer, PhD, associate professor of medicine in the Division of Allergy and Clinical Immunology at the Colorado University School of Medicine, “There is a unique microbiome associated with men who have sex with men that drives immune activation in the gut that may also drive higher levels of HIV infection. But we still don’t know exactly why this is.”

Bottom line

Not much is known about the impact of sexual activity on the immune system. Thus far, research suggests that sexual activity offers, a stronger immune system in some cases, and it’s an area that warrants further research.


Charnetski CJ, Brennan FX. Sexual frequency and salivary immunoglobulin A (IgA). Psychological Reports 2004 Jun 1

Li SX et al. Gut microbiota from high-risk men who have sex with men rive immune activation in gnotobiotic mice and in vitro HIV infection. PLoS Pathogens 2019 Apr 4; 15(4): e1007611

Lorenz TK et al. Sexual activity modulates shifts in TH1/Th2 cytokine profile across the menstrual cycle: an observational study. Fertility and Sterility 2015 Dec; 104(6): 1513-21

McKean KA, Nunney L. Increased sexual activity reduces male immune function in Drosophila melanogaster. Proceedings of the National Academy of Sciences USA 2001 Jul 3; 98(14): 7904-09

Pennell LM et al. Sex affects immunity. Journal of Autoimmunity 2012 May; 38(2-3

University of Colorado Anschutz Medical Campus. “Sexual behavior may influence gut microbiome: Researchers say men who have sex with men have unique microbiomes, may impact immune system.” ScienceDaily 10 April 2019.