Male fertility – what affects sperm and what helps
What a semen analysis measures, the everyday things that reduce sperm quality, which medicines and conditions matter, and when to get checked.
Half the picture, half the time
Roughly half of couples having difficulty conceiving have a contributing male factor. It is still common for the woman to be investigated extensively while the man is not tested at all, which wastes months. A semen analysis is a simple, inexpensive test and it is a reasonable first step rather than a last resort.
- It looks at how many sperm there are, how well they move, and what shape they are.
- One abnormal result does not settle anything. Sperm production takes about three months, so results vary and the test is usually repeated.
- A normal result is reassuring but does not rule out every male factor.
What reduces sperm quality
- Smoking, heavy alcohol use and cannabis.
- Anabolic steroids and testosterone taken for muscle building — these suppress the body's own sperm production, sometimes for a long time after stopping, and sometimes permanently.
- Heat: prolonged hot baths, saunas, and a laptop on the lap. The testes sit outside the body for a reason.
- Being significantly overweight.
- Untreated infections, including sexually transmitted infections, which can scar the tubes that carry sperm.
- Some prescription medicines, and some occupational exposures to solvents, pesticides and heavy metals.
- A varicocele — enlarged veins in the scrotum — which is treatable.
Medicines that can affect fertility and are worth discussing before or during treatment:
Testosterone — Sustanon, Nebido, Depo-Testosterone
Male hypogonadism; delayed puberty
Finasteride — Proscar, Profina, Accord Finasteride
Benign prostatic hyperplasia (shrinks prostate); male pattern hair loss (1 mg)
What actually helps
- Stop smoking, and cut alcohol and cannabis. This is the highest-value change and the effect shows within a few months.
- Stop anabolic steroids, and tell the clinician honestly if you have used them. Recovery is possible but takes time and sometimes needs help.
- Get to a healthier weight and stay active.
- Avoid prolonged heat to the groin.
- Get any infection treated, and test for sexually transmitted infections.
- Give it about three months before re-testing — that is how long a new batch of sperm takes.
Common questions
- How long does it take to improve sperm quality?
- About three months, because that is roughly how long sperm take to develop. Changes such as stopping smoking or losing weight show up on a repeat test after that interval rather than immediately.
- Does testosterone help with fertility?
- No — it does the opposite. Testosterone taken from outside the body suppresses the signal that drives sperm production, and the effect can last well after stopping. Discuss fertility before starting it.
- What does a semen analysis test for?
- How many sperm there are, how well they move and what shape they are. It is simple and inexpensive, and it is usually repeated because results vary between samples.
Sources
- Primary Healthcare Standard Treatment Guidelines and Essential Medicines ListNational Department of Health, South Africa
- Adult Primary Care guide: symptom-based integrated approach to the adult in primary careNational Department of Health, South Africa
- Clinical and public health guidanceWorld Health Organization
- Medicines Online Directory and approved patient information leafletsSouth African Health Products Regulatory Authority
Last reviewed 11 August 2026.