Four fears always come back with male sterilisation: my testosterone will drop, my libido will vanish, it will give me prostate cancer, and I will be left in pain. Every clinic page waves them away in one sentence, with no source.
That is not an answer. That is reassurance.
Below is what the best available research shows for each feared downside, with an honest note on how strong that evidence is. For one of the four the answer is less comfortable than clinics suggest, and for one of them no research exists that can help you at all.
What are the long-term downsides of male sterilisation?
The hard downsides are that it is permanent, that it does not protect against STIs, and that a small group of men are left with persistent pain. The feared hormonal downsides are not found by the research. Thuisarts.nl, the patient site of the Dutch College of General Practitioners (NHG), names permanence and the surgical risks above all.
The first is the heaviest, and it is also the only one without a number.
The table below lists the five big worries. Pay attention to the last column, because it is missing everywhere else.
| The feared downside | What the best research shows | How strong is the evidence |
|---|---|---|
| Lower testosterone | No significant difference after adjustment, in 437 men aged 40 plus (PMID 29658249) | Observational, reasonably consistent |
| Less interest in sex | Desire and satisfaction rose slightly on the IIEF questionnaire (PMID 16255791) | Small study, 64 men, weak but consistent with the anatomy |
| Erection problems | Not one case caused by the procedure in that same group (PMID 16255791) | Same small study, short follow-up |
| Prostate cancer | Weak association with cancer overall, no association with aggressive or fatal forms (PMID 28715534) | Large meta-analysis, but with a likely explanation that is not causal |
| Persistent pain | 0.14 percent in an audit of 105,393 procedures, 5 percent in a meta-analysis | Contested, a factor of 35 between sources |
The row that needs explaining is the fourth.
Does sterilisation lower your testosterone?
According to the research, no. Your vas deferens transports sperm, not hormones. Testosterone is made in the Leydig cells of your testicle and goes straight into your bloodstream, along a route the procedure never touches. The measurements confirm what the anatomy predicts.
One study compared 232 sterilised men with 205 who were not, all aged 40 or over.
Before adjustment the sterilised group even looked slightly higher on testosterone, SHBG and LH. After adjusting for confounders, no statistically significant difference remained (PMID 29658249).
That is exactly the kind of result you expect when nothing is going on.
What that means practically: if you feel flat and low years after your sterilisation, the procedure is not the suspect. Which signals do fit low testosterone is covered in low testosterone in men.
Will you lose interest in sex?
The research points the other way, though it is small. Among 64 men followed with the IIEF questionnaire, scores for desire and satisfaction rose slightly after the procedure, from 64.06 to 65.64. No case of surgery-related erectile dysfunction was seen (PMID 16255791).
Sixty-four men is not a large study, and you should weigh that.
The most commonly given explanation is not hormonal but practical: the fear of an unplanned pregnancy falls away. That can make sex more relaxed. It is a plausible explanation, not a proven mechanism.
So I would not turn it into a promise. But it is the opposite of what the forums fear.
How libido and hormones relate is explained in libido and testosterone and in low sex drive in men.
Does a vasectomy cause prostate cancer?
For the forms that actually matter: no. This is the answer that needs the most nuance, because something was found. A 2017 meta-analysis in JAMA Internal Medicine found a weak association with prostate cancer overall, but no association with aggressive or fatal prostate cancer.
The numbers help more than words here.
For prostate cancer overall, the analysis of cohort studies at low risk of bias landed on a rate ratio of 1.05 (95 percent confidence interval 1.02 to 1.09). For high-grade prostate cancer it was 1.03 (0.89 to 1.21) and for fatal prostate cancer 1.02 (0.92 to 1.14), neither significant (PMID 28715534).
The authors concluded this is not a reason to avoid a vasectomy.
That pattern, a minute association with detected cancer and none at all with the dangerous forms, is precisely what detection bias looks like. Men who see a urologist get blood work and a PSA measurement more often, so something already present is found more often.
Important: that is my reading of the pattern, and it is the common explanation, but it is an interpretation and not proof. What we can say is that the fatal variant showed no association, and that is the outcome that counts.
How likely are you to be left with persistent pain?
Unlikely, but how unlikely depends on the source. A prospective audit of 105,393 procedures recorded persistent pain complaints in 0.14 percent, roughly 1 in 714 men (PMID 38989696). A 2020 meta-analysis landed on 5 percent (PMID 32164161).
That is a factor of 35, and both figures were collected honestly.
That same meta-analysis produces the one number you can use beforehand: with the scalpel method 24 percent of men reported pain, with the no-scalpel technique 7 percent.
Why those sources sit so far apart is worked through in pain after a vasectomy.
Which downside has no research behind it?
Regret. There is no blood value, no scan and no questionnaire that tells you in advance how you will view this decision in ten years. It is the only downside on this list without a number, and at the same time the only one that repairs badly.
Thuisarts is brief about it: a repair operation is difficult and often fails, and men usually stay less fertile afterwards.
The figures behind that sentence are firm. With a reversal within three years, sperm returned in 97 percent and 76 percent of couples conceived. At fifteen years or longer it was 71 percent and 30 percent (PMID 1997700).
That second column falls faster than the first. That is the whole difference between patent and a child.
Say you are 34, you have two children and your relationship is solid. If you are sterilised now and your situation changes at 46, you land in the nine to fourteen year row. That row carries a pregnancy chance of around 44 percent.
The full breakdown is in reversing a vasectomy.
What can you do with this?
Two things. Ask the clinic which technique they use, because that is the only downside on this list you have any influence over. And treat the procedure as permanent, even knowing that repair operations exist.
What you cannot do is solve the regret question with a test. That test does not exist.
If you feel flat or low after your sterilisation, the research does not point at the procedure. Some men then map their hormones with the Hormones Man panel or the testosterone panel, to see whether something else is going on. Always discuss an abnormal result with your GP.
More background on male hormones is in hormonal health in men, and the full story on the procedure itself in vasectomy: how it works.
Got a consultation coming up? Take this list with you and ask the doctor what they make of each point. A good clinic will welcome that conversation.
Sources
- Bhindi B, et al. The Association Between Vasectomy and Prostate Cancer: A Systematic Review and Meta-analysis. JAMA Internal Medicine. 2017. PMID 28715534.
- Shi YJ, et al. Vasectomy has no obvious longterm influence on the levels of serum androgens in aging males. Zhonghua Nan Ke Xue. 2017. PMID 29658249.
- Bertero E, et al. Assessment of sexual function in patients undergoing vasectomy using the international index of erectile function. International Brazilian Journal of Urology. 2005. PMID 16255791.
- Peacock J, et al. Complications of vasectomy: results from a prospective audit of 105 393 procedures. BJU International. 2024. PMID 38989696.
- Auyeung AB, et al. Incidence of Post-Vasectomy Pain: Systematic Review and Meta-Analysis. International Journal of Environmental Research and Public Health. 2020. PMID 32164161.
- Belker AM, et al. Results of 1,469 microsurgical vasectomy reversals by the Vasovasostomy Study Group. Journal of Urology. 1991. PMID 1997700.
- Thuisarts (NHG). Sterilisatie bij man. thuisarts.nl
Every blood test result at Caliber includes a professional assessment from a BIG-registered doctor. For treatment decisions, always discuss your results with your GP.
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