Ejaculation and Prostate Cancer: What Science Really Says

Conversations around prostate cancer often focus on screenings, diet, and family history—but one lesser-known factor has quietly emerged from clinical studies: ejaculation frequency. Researchers are uncovering a potential link between how often a man ejaculates and his risk for developing prostate cancer, particularly low-grade forms. While the science is far from settled, the findings are intriguing enough to warrant real discussion.

The idea that something as natural—and frankly, enjoyable—as ejaculation could play a role in cancer prevention has understandably captured attention. However, it's essential to unpack the nuance behind the research. This isn’t about pushing a narrative of “more is better,” but rather understanding what the data actually says and what it could mean for long-term prostate health.

Why prostate health deserves attention

Prostate cancer remains one of the most common cancers in men worldwide. According to the American Cancer Society, approximately 1 in 8 men will be diagnosed with prostate cancer during their lifetime. While many cases are slow-growing, others can be aggressive and life-threatening.

With such high incidence, the conversation around prevention matters. And yet, most prevention strategies focus on diet (like reducing red meat or dairy), physical activity, or screening protocols. Few people are talking about ejaculation—and even fewer understand how it may factor into risk reduction.

What the Harvard study actually found

In 2016, researchers from Harvard’s Health Professionals Follow-Up Study published data that made waves in the urology and oncology community. Over 32,000 men were followed for 18 years, reporting their ejaculation frequency at multiple points across their lives—in their 20s, 40s, and early 50s.

What they found was striking: Men who ejaculated 21 or more times per month had a 20% lower risk of developing prostate cancer compared to those ejaculating only 4 to 7 times per month. The protective effect was seen across different decades of life, but was particularly notable in men in their 40s.

That kind of longitudinal data over nearly two decades isn’t easy to come by, and it sparked a renewed interest in the potential biological benefits of regular ejaculation.

Is ejaculation protective? The proposed mechanisms

Researchers have yet to definitively pin down why frequent ejaculation might lower prostate cancer risk, but several theories have emerged. The most prominent is the “prostate drainage” hypothesis. Ejaculation helps clear the prostate gland of secretions, including potential carcinogens or inflammatory substances.

Another possible explanation is hormonal regulation. Regular sexual activity may influence levels of testosterone, DHT (dihydrotestosterone), and other androgens in ways that reduce the likelihood of unchecked prostate cell proliferation. Ejaculation may also affect immune response, reducing chronic inflammation that could contribute to DNA damage over time.

There’s even discussion around mental health—regular sexual activity can reduce stress, improve sleep, and support overall well-being. Those indirect benefits can still play a role in lowering cancer risk.

Debunking myths and addressing study limitations

While the correlation is strong, we have to be careful not to make the leap into causation. Just because frequent ejaculation appears to reduce risk doesn’t mean it’s the direct cause. It’s entirely possible that men with high ejaculation frequency also maintain healthier diets, exercise more, have better access to healthcare, or experience lower stress levels.

It’s also worth noting that not all studies support the finding. Some smaller or regional trials have shown neutral or even contradictory results—though these tend to have smaller sample sizes and shorter follow-up periods. Most importantly, ejaculation frequency does not appear to protect against the most aggressive forms of prostate cancer, which are the deadliest.

What “frequent” actually means in research

In scientific terms, “frequent” ejaculation usually refers to 21 or more times per month—which averages out to about 5 times per week. That can include sex with a partner, masturbation, or nocturnal emissions. It’s not about method, but total frequency.

To be clear, the benefit doesn’t kick in at exactly 21—research shows a graded relationship where even moderately high frequency (say, 13–20 times per month) may offer protective benefits compared to lower frequencies. But the highest statistical reduction in risk came from those who consistently stayed above that 20-times threshold.

Should you increase your ejaculation frequency?

For most men, increasing ejaculation frequency is safe—provided it's not interfering with daily life, relationships, or emotional well-being. There are no known physical risks to frequent ejaculation. In fact, beyond the potential prostate benefits, it may support mood stability, stress reduction, improved sleep, and even testicular health.

Of course, ejaculation frequency should never replace annual checkups, PSA testing, or conversations with your doctor. But if you're looking for low-effort ways to support your health, and you’re otherwise healthy and sexually active, this is one lifestyle factor you may want to track.

Final thoughts on ejaculation and prostate cancer risk

Here’s the truth: we don’t yet have all the answers. But we do have strong data suggesting that frequent ejaculation is associated with lower prostate cancer risk, particularly for less aggressive forms. The mechanism isn’t fully understood, and it’s not a cure-all—but it’s a promising addition to the broader conversation about prevention.

It’s safe, natural, and potentially beneficial—so there’s no harm in “working on your number,” as some physicians have joked. Just make sure it’s one part of a broader, intentional approach to prostate health that includes regular screenings, a plant-forward diet, physical activity, and open dialogue with your healthcare provider.

Citations

https://www.health.harvard.edu/mens-health/ejaculation_frequency_and_prostate_cancer
https://pubmed.ncbi.nlm.nih.gov/27033442/
https://www.procure.ca/en/2020/09/20/does-ejaculation-protect-against-prostate-cancer/
https://www.urologyhealth.org/healthy-living/urologyhealth-extra/magazine-archives/fall-2020/ask-the-experts-does-having-more-ejaculations-lessen-the-chance-of-prostate-cancer
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5040619/