Vasectomy myths: what the evidence actually says

Myth: it lowers testosterone or kills your sex drive

A vasectomy interrupts one thing: the tube that carries sperm. Testosterone is made in the testes and travels around your body in the bloodstream — a route the procedure never touches. Healthy Male, Australia's national men's health organisation, is blunt about it: your levels of testosterone and other hormones won't be affected.

The same goes for function. A 2025 study of middle-aged men in the German Andrology journal cohort found no association between vasectomy and sexual dysfunction, including erectile problems. And a 2015 Stanford analysis in The Journal of Sexual Medicine of more than 5,000 men found vasectomised men actually reported having sex more often — about 5.9 times a month versus 4.9 for non-vasectomised men.

That last finding isn't magic. Remove the background worry of pregnancy and, for many couples, sex gets easier and more frequent. Healthy Male notes sexual satisfaction may increase after vasectomy.

Myth: it causes prostate cancer

This one refuses to die because a few early observational studies found weak associations. The bigger and better the study, the more the link evaporates. A 2022 systematic review and meta-analysis in European Urology Open Science pooled 37 studies covering some 16.9 million patients: no significant association between vasectomy and high-grade, advanced or fatal prostate cancer.

A 2017 meta-analysis of 53 studies in JAMA Internal Medicine reached the same conclusion — no meaningful association once study bias was accounted for. The tiny residual association with prostate cancer diagnosis (not death) is generally put down to detection: men who have vasectomies see doctors more, so more cancers get found.

If a vasectomy caused prostate cancer, datasets of this size would show it. They don't.

Myth: it's basically castration

The "getting desexed" line your mates borrow from the vet is describing a different operation — desexing a pet removes the testes. A vasectomy removes nothing. Your testes stay where they are and keep doing both their jobs: making testosterone (unchanged, see above) and making sperm — which your body simply reabsorbs, the same way it recycles other unused cells.

The jokes will happen anyway. The reality is a 15–30 minute procedure under local anaesthetic, a small entry in the skin, and everything you had before still present and working. If the wording matters to whoever you're discussing it with, our guide on talking to your partner may help.

Myth: your semen changes noticeably

Sperm make up only a few percent of semen volume — most of the fluid comes from the seminal vesicles and prostate, both untouched by a vasectomy. After the procedure, ejaculation looks, feels and measures essentially the same; the only difference is microscopic. That's also why you can't tell whether the procedure worked by looking: it takes a lab and a semen test.

Myth: you walk out sterile

The opposite myth to "it doesn't work" — the belief that it works instantly. It doesn't. Sperm already downstream of the operation site stay viable for weeks, which is why clinics ask you to use other contraception until a semen test at about 12 weeks and 20 ejaculations confirms you're clear.

This matters because many men never complete that test — in some published clinic cohorts, most don't. The 1-in-2,000 reliability figure belongs to the men who do. If you take one practical thing from this page: book the test, and don't stop other contraception until your doctor confirms the result. Full detail in our semen test guide.

Myth: you can throw out the condoms for good

A vasectomy prevents pregnancy — extremely well, about 1 in 2,000 failures after a clear test. It does nothing against sexually transmitted infections. Healthdirect's advice is the standard one: if there's any STI risk in your situation, condoms are still the tool for that job, vasectomy or not.