Headlines claiming there is an “exact number” of times men must ejaculate each month to prevent prostate cancer oversimplify a much more nuanced body of medical research.

The claim traces back primarily to a large observational study published in European Urology, which followed tens of thousands of men over several decades. Researchers observed that men who reported more frequent ejaculation had a lower overall risk of developing prostate cancer compared with those who ejaculated less often.

Specifically, the study found that men who ejaculated around 21 times per month had a statistically lower risk than those who averaged fewer than seven. However, researchers emphasized that this was a correlation — not proof of causation — a distinction repeatedly highlighted by Harvard Medical School in its analysis of the data.

Medical experts stress that ejaculation frequency is only one small factor among many. Genetics, age, ethnicity, diet, physical activity, and access to regular screening play a far more significant role in prostate cancer risk, according to guidance from the American Cancer Society.