Does masturbation lower testosterone or harm health? What the evidence says

There is no good evidence that masturbation lowers testosterone or damages health, and the claim that it does is a persistent myth. In a controlled study of ten healthy men, masturbation-induced orgasm did not change plasma testosterone at all [s1]; and in two large cohorts, men who ejaculated most often had modestly lower — not higher — rates of prostate cancer [s2][s3].

The question is one of the most searched in men's health, and it is fed by decades of folklore about lost vitality. The measurable biology tells a duller and more reassuring story.

What orgasm does to testosterone

The most direct test of the "masturbation drains testosterone" idea measured it. Researchers drew blood continuously from ten men during arousal and masturbation-induced orgasm, on two occasions — before and after a three-week period of abstinence [s1]. Orgasm raised blood pressure, heart rate, adrenaline and prolactin, but plasma testosterone was unaltered by orgasm on both occasions [s1].

One finding in that study is often quoted out of context: testosterone was somewhat higher after the three-week abstinence than before it [s1]. That is a short-lived fluctuation in a ten-man experiment, not evidence that regular ejaculation lowers a man's testosterone over time — and the same study found the act of orgasm itself moved the hormone not at all [s1]. No study has shown that masturbation causes clinically low testosterone, hair loss, blindness, weaker erections or infertility.

The one robust health signal points the other way

If anything, the best-quality evidence on ejaculation frequency runs opposite to the folklore. Two prospective studies followed tens of thousands of men in the Health Professionals Follow-up Study, and both linked higher ejaculation frequency — a measure that explicitly includes masturbation as well as intercourse — to lower prostate cancer risk.

The first followed 29,342 men over 222,426 person-years and recorded 1,449 prostate cancers [s2]. Averaged across a lifetime, men reporting 21 or more ejaculations a month had a relative risk of 0.67 (95% CI 0.51-0.89) compared with men reporting 4 to 7, and for ejaculation frequency in the previous year the risk fell to 0.49 (95% CI 0.27-0.88); the authors concluded ejaculation frequency "is not related to increased risk of prostate cancer" [s2]. A decade of extra follow-up, covering 31,925 men over 480,831 person-years and 3,839 cancers, found the same direction: for 21 or more versus 4 to 7 ejaculations a month, the hazard ratio was 0.81 (95% CI 0.72-0.92) for frequency measured at ages 20-29 and 0.78 (95% CI 0.69-0.89) at ages 40-49 [s3].

Those numbers deserve careful handling. Both studies are observational, so they cannot prove that ejaculating more prevents cancer rather than simply tracking with something else. The measure they used, "ejaculation frequency," combines intercourse, masturbation and nocturnal emission, so none of it isolates masturbation specifically [s2]. And the protective association was driven by low-risk disease and did not extend clearly to aggressive cancers [s3]. One obvious worry — that men who ejaculate more simply get tested more, and so are diagnosed more — was addressed directly: PSA testing rates were similar across frequency groups, and the association held when analysis was restricted to screened men [s3]. The point for a reader is narrower and firmer: across two large studies, frequent ejaculation was not associated with any increase in prostate cancer, and the myth of harm has no support here [s2][s3].

A near-universal behaviour

Part of what makes the myth sticky is embarrassment about how common the behaviour is. The National Survey of Sexual Health and Behavior, a probability sample of 5,865 Americans aged 14 to 94, found masturbation was common throughout the lifespan, and more common than partnered sexual activity during adolescence and in people aged 70 and over [s4]. It is, in other words, a normal part of most people's sexual lives at every age [s4].

The honest bottom line: masturbation does not lower testosterone in any way the evidence can detect, and the health association that does exist — with prostate cancer — points modestly in the reassuring direction. Men worried about genuinely low testosterone should look elsewhere, at the causes and the evidence on testosterone therapy, at low libido and its many drivers, and at the testosterone-optimisation trend that sells solutions to a problem most men do not have. On prostate cancer, the ejaculation data sit alongside the separate, reassuring evidence on vasectomy and prostate risk and on testosterone therapy and the prostate.