Masturbation does appear to temporarily boost certain parts of the immune system. Sexual arousal and orgasm increase the number of white blood cells circulating in the bloodstream, particularly natural killer cells, which are one of the body’s front-line defenses against viruses and tumors. But the evidence is limited, mostly conducted on men, and the effects seem to be short-lived rather than a lasting upgrade to immune function.
What Happens to Immune Cells After Orgasm
The most direct evidence comes from a study that drew blood continuously during sexual arousal and after orgasm, then analyzed the immune cells present. Sexual arousal and orgasm increased the total number of white blood cells in the bloodstream, with natural killer cells showing the most notable spike. Other types of white blood cells stayed about the same, and none decreased. So at minimum, masturbation doesn’t suppress your immune system, and it does temporarily mobilize some of the cells your body uses to fight infection.
Researchers measured immune markers at 5 and 45 minutes after orgasm, but the available data doesn’t clearly show how long the elevation lasts before returning to baseline. This is a key limitation: a temporary spike in natural killer cells isn’t the same thing as being more resistant to illness over time. Your body mobilizes these same cells during exercise, stress, and other forms of physical arousal too.
The IgA Connection
A separate line of research looked at immunoglobulin A (IgA), an antibody found in saliva, mucus, and other secretions that serves as one of the body’s first barriers against respiratory and gut infections. People who had sex at a moderate frequency (once or twice a week) showed significantly higher salivary IgA levels than people who had sex rarely, very frequently, or not at all. Interestingly, the very frequent group didn’t show the same benefit, which suggests that more isn’t necessarily better when it comes to immune markers and sexual activity.
This particular study looked at partnered sex rather than masturbation specifically, so it’s not clear whether solo orgasm produces the same IgA response. Some of the immune benefit from partnered sex could come from factors unrelated to orgasm itself, like physical closeness, emotional bonding, or even exposure to a partner’s microbes.
Most Research Has Been Done on Men
Nearly all the direct research on masturbation and immune response has been conducted exclusively on people with penises. There’s very little data on how masturbation affects immune markers in people with vaginas. The hormonal cascade after orgasm (including the release of oxytocin and prolactin, and the drop in cortisol) occurs regardless of sex, so there’s reason to think some of the effects would be similar. But that’s an assumption, not a confirmed finding.
Indirect Benefits Through Sleep and Stress
Some of the immune benefit from masturbation likely comes through indirect pathways rather than a direct immune cell boost. The most well-supported of these is sleep. In an Australian study of more than 750 men and women, over 50% reported improved sleep quality after masturbating to orgasm. In a separate American study, about a third of women who masturbated said they did so specifically to help them fall asleep.
The physiological chain makes sense: orgasm triggers muscle relaxation, raises oxytocin (which has both calming and anti-inflammatory effects), raises prolactin, and lowers cortisol. Cortisol is the body’s primary stress hormone, and chronically elevated levels of it suppress immune function and increase inflammation. Anything that reliably lowers cortisol and improves sleep quality is, by extension, supporting your immune system. Sleep is one of the most powerful regulators of immune health, so this indirect path may matter more than the temporary spike in natural killer cells.
What This Actually Means for Your Health
If you’re wondering whether masturbation can replace other immune-supporting habits, the answer is no. The direct immune effects are real but modest and temporary. You’d get a comparable or larger boost from a 30-minute walk, a full night of sleep, or managing chronic stress. Where masturbation fits in is as one small piece of a larger picture: it reduces cortisol, promotes relaxation, improves sleep for many people, and temporarily increases immune cell activity. None of those effects are dramatic on their own, but none of them are harmful either.
The bottom line is that masturbation isn’t a medical intervention for your immune system, but it’s not hurting it. The temporary bump in natural killer cells and the downstream effects on sleep and stress hormones are genuine, if small. For people who already masturbate, there’s a mild immune argument in its favor. For people who don’t, the existing evidence isn’t strong enough to recommend it as an immune strategy over proven fundamentals like sleep, exercise, and nutrition.