Testosterone and Immune Function: Why Men Get Sicker (and What To Do About It)
Across many infections and vaccines, male and female immune systems behave differently. Men have on average poorer antibody responses to some vaccines and worse outcomes from some infections, while women are far more likely to develop autoimmune diseases. Sex hormones are one proposed explanation, and testosterone appears to have immunosuppressive effects. But genes, behavior and other factors matter too, and most of the evidence is observational.
Key takeaways
- In a study of influenza vaccine responses in 53 females and 34 males, women had higher antibody responses than men, and men with elevated testosterone had the lowest antibody responses.[1]
- Autoimmune diseases affect about 8% of the population, and about 78% of those affected are women.[2]
- A meta-analysis of more than 3 million COVID-19 cases found that men had higher odds of ICU admission (OR 2.84) and death (OR 1.39) than women.[3]
- Testosterone is lower in seriously ill hospitalized men, and more so with severe illness.[4] If you are often ill, or have symptoms of low testosterone, talk to a doctor. This is general education, not medical advice.
The Testosterone-Immunity Trade-Off
Reviews describe sex differences in immune responses that appear after puberty and before reproductive senescence, which suggests that both genes and hormones are involved.[5] A 2015 review of research on androgens found evidence from different studies pointing to an immunosuppressive role of testosterone on several components of the immune system, while noting that the underlying molecular mechanisms remain unknown.[6]
One way to think about this is a trade-off: a less reactive immune system may mean a weaker response to some infections and vaccines, but also lower risk of the immune system attacking the body's own tissues. That framing is a hypothesis, not a proven rule, and researchers emphasize that sex differences in autoimmune disease also reflect genetics, reproductive factors and other influences.[7]
What Research Says About “Man Flu”
Whether men truly suffer more from colds and flu is hard to prove, because symptom severity is subjective and behavior varies. The better evidence comes from vaccine studies and hospital outcomes.
In a systems analysis of the response to the seasonal influenza vaccine, women had higher antibody responses and more inflammatory cytokines than men regardless of age. Among men, a cluster of testosterone-related genes correlated with poor virus-neutralizing activity, and men with elevated serum testosterone had the lowest antibody responses.[1] This was a study of 87 people, so it shows an association, not that testosterone causes weaker vaccine protection.
A similar sex gap appears in COVID-19 outcomes. In a meta-analysis of 3,111,714 global cases, there was no difference in the proportion of males and females with confirmed infection, but male patients had almost three times the odds of requiring ICU admission (OR 2.84, 95% CI 2.06 to 3.92) and higher odds of death (OR 1.39, 95% CI 1.31 to 1.47).[3] The data do not separate the roles of hormones, other illnesses and behavior.
The Autoimmune Side
The flip side is that autoimmune diseases are more common in women. One review reports that autoimmune diseases affect about 8% of the population, 78% of whom are women, and that the reason is unclear.[2] A separate review concluded that for most autoimmune diseases females are more frequently affected, and discussed possible contributors including sex hormones, genetic predisposition, reproductive factors and epigenetics.[7]
It is tempting to say testosterone “protects” men from autoimmune disease, but the research does not prove that. Some autoimmune diseases are in fact more prevalent in males, so the picture varies by condition.[2] For men concerned about hormonal balance, the practical message is simply that hormones are one part of a complex system.
Lifestyle Habits That Support Both
We found no evidence that raising testosterone improves immune resilience in men whose levels are already normal. What is well supported is that general health habits matter for both systems.
✓ Supportive Habits
- •Adequate, regular sleep
- •Regular moderate exercise
- •A varied diet with enough protein, vitamins and minerals
- •Staying up to date on recommended vaccines
- •Managing stress and avoiding smoking
✗ Habits That Work Against You
- •Chronic sleep deprivation
- •Chronic stress
- •Excess body fat and a sedentary lifestyle
- •Heavy alcohol use
- •Using testosterone or anabolic steroids without medical supervision
These overlap with the habits that support healthy testosterone: adequate sleep, regular exercise, stress management and balanced nutrition. Taking testosterone or anabolic steroids without medical supervision carries risks, so see a doctor for any hormone questions.
Illness and Testosterone
In a study of 59 men and 42 postmenopausal women admitted to critical care units, men's admission testosterone was lower than in healthy controls, and levels were lower still in men with severe illness (APACHE II score above 15) than in men with mild or moderate illness.[4] That is research on seriously ill hospital patients. It does not tell us how much a cold or flu changes testosterone, though it shows that the body can turn down reproductive hormones during major illness. We found no evidence that you need to do anything special to protect testosterone while sick.
General Wellness Habits While You Are Sick
Rest and sleep
Give your body extra time to sleep and recover rather than pushing through.
Skip hard training
If you have a fever, body aches or chest symptoms, rest. Return to exercise gradually once you feel well.
Eat and drink normally
Stay hydrated and keep eating nutritious foods. Do not start supplements or drastically change your diet without advice from a doctor or pharmacist.
See a doctor if it does not resolve
Seek care for a high fever, trouble breathing, symptoms that last or return, or fatigue and low libido that persist after you recover.
The Bottom Line
Testosterone appears to have immunosuppressive effects, and men show differences from women in vaccine responses and some infection outcomes. But the evidence is largely observational, other factors are involved, and it does not support using testosterone as an immune strategy. For general guidance on testosterone levels by age and daily habits, see our other guides, and talk to a doctor about symptoms.
Related Reading
- How to Increase Testosterone Naturally: the lifestyle levers that support healthy testosterone.
- The Complete T-Maxing Guide: the full habit stack for long-term hormonal health.
References
- Furman D, Hejblum BP, Simon N, et al.. Systems analysis of sex differences reveals an immunosuppressive role for testosterone in the response to influenza vaccination. Proc Natl Acad Sci U S A. 2014. doi.org/10.1073/pnas.1321060111
- Fairweather D, Frisancho-Kiss S, Rose NR. Sex differences in autoimmune disease from a pathological perspective. Am J Pathol. 2008. doi.org/10.2353/ajpath.2008.071008
- Peckham H, de Gruijter NM, Raine C, et al.. Male sex identified by global COVID-19 meta-analysis as a risk factor for death and ITU admission. Nat Commun. 2020. doi.org/10.1038/s41467-020-19741-6
- Spratt DI, Cox P, Orav J, Moloney J, Bigos T. Reproductive axis suppression in acute illness is related to disease severity. J Clin Endocrinol Metab. 1993. doi.org/10.1210/jcem.76.6.8501163
- Klein SL, Flanagan KL. Sex differences in immune responses. Nat Rev Immunol. 2016. doi.org/10.1038/nri.2016.90
- Trigunaite A, Dimo J, Jorgensen TN. Suppressive effects of androgens on the immune system. Cell Immunol. 2015. doi.org/10.1016/j.cellimm.2015.02.004
- Ngo ST, Steyn FJ, McCombe PA. Gender differences in autoimmune disease. Front Neuroendocrinol. 2014. doi.org/10.1016/j.yfrne.2014.04.004
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