Testosterone and Male Fertility: What Helps and What Backfires

The short answer

• Testosterone is what drives sperm production in the testes, so healthy levels matter when you're trying to conceive.
• Taking testosterone from outside the body, whether that's TRT, gels, injections or steroids, can switch your own sperm production off.
• Sleep, body weight, alcohol and zinc all influence how much testosterone your body makes on its own.

When a couple starts trying to conceive, most of the attention tends to land on her, from tracking her cycle to getting her bloods done and starting a prenatal. Yet a male factor contributes in around half of the couples who struggle to conceive, and testosterone sits right at the centre of male reproductive health. It's also one of the most misunderstood parts of male fertility, because more testosterone sounds like it should mean better sperm, when the way some men go about raising it can do the opposite.

What does testosterone have to do with sperm?

Most of a man's testosterone is made in the testes, where one of its main jobs is driving sperm production, and the levels inside the testes are far higher than anything that shows up on a blood test. Low testosterone often shows up as a low libido, low energy or a flat mood, and for couples trying to conceive it can also mean fewer sperm.

Sperm take roughly two and a half months to develop, so the habits you have today are shaping the sperm you'll be making in around three months' time.

Why taking testosterone can backfire

This is the point we most want men to understand before they start trying. When testosterone comes from outside the body, whether it's prescribed TRT, a gel, injections or steroids from the gym, the brain senses there's plenty in the blood and turns down the signals that tell the testes to make their own. Testosterone inside the testes falls, sperm production falls with it, and in some men it stops completely.

That's why the American Urological Association's infertility guideline advises doctors not to prescribe testosterone to men who want children now or in the future. If you're already taking it and you're trying to conceive, speak with your doctor before you stop or change anything, because there are other treatments that can raise testosterone without shutting down sperm production.

What helps your own testosterone

Sleep

In a University of Chicago study, healthy young men who slept less than five hours a night for one week had 10 to 15% lower testosterone, an effect the researchers compared to ageing 10 to 15 years. Aiming for seven to nine hours on most nights, rather than catching up on weekends, gives your body the best chance of keeping your levels where they should be.

Body weight

Carrying extra weight, particularly around the middle, is linked with lower testosterone, and a 2013 analysis of 24 studies found testosterone rose when men lost weight, with bigger rises in the men who lost more.

Alcohol

An occasional drink isn't the concern, but regular heavy drinking is harmful to sperm quality, so the three months before you start trying is a good time to cut back.

Zinc

Zinc is one of the most important minerals for male reproductive health. In a well-known study, healthy young men who reduced their zinc intake for 20 weeks saw their testosterone fall by about three quarters, while older men who were low in zinc saw their levels rise after six months of supplementation. Oysters, red meat, seafood and pumpkin seeds are good food sources, though most men don't eat oysters often enough to rely on them.

What about testosterone boosters?

Testosterone boosters are heavily marketed, but most don't hold up to scrutiny. A 2020 study of 50 popular "T booster" supplements found 90% claimed to raise testosterone, yet only around a quarter of their ingredients had research to support that, and 10% had evidence of lowering it. Australia's Healthy Male also points to a study that found more than 1 in 20 supplements on the Australian market contained undeclared steroids, which is the last thing you want to be taking when you're trying to conceive.

Where Prenatal Support [Him] fits in

Prenatal Support [Him] covers the nutrient side of male preconception care, with 30mg of zinc as zinc glycinate alongside selenium, lycopene and vitamins C and E to support sperm health, and it's designed to support healthy testosterone and the full sperm cycle with nothing hidden on the label. The rest comes down to sleep, weight and alcohol, and starting around three months before you plan to conceive gives the sperm you're making the full benefit.

This is general information only. Please speak with your GP or healthcare practitioner before starting or stopping any medication or supplement.