Men’s sexual health, defined

Supplements & nutrients Ashwagandha Ashwagandha (Withania somnifera) is an Ayurvedic herb sold for stress and men's health. A 2026 meta-analysis of 23 trials found it raised testosterone in men and lowered cortisol, and studies in men with low sperm counts reported better semen measures. Sperm & fertility Azoospermia Azoospermia means there are no sperm at all in the ejaculate, even after the sample has been spun down and examined under a microscope. It is either obstructive (sperm are made but blocked) or non-obstructive (the testes make few or none).

Supplements & nutrients Coenzyme Q10 Coenzyme Q10 (CoQ10) is an antioxidant the body uses to make energy in cells, including sperm. In trials of infertile men, CoQ10 supplements raised CoQ10 levels in semen and improved sperm motility, and a systematic review found better semen parameters across studies.

Erections & performance Delayed ejaculation Delayed ejaculation (DE) is persistent difficulty reaching climax and ejaculating, or being unable to at all, despite wanting to. It's less common than premature ejaculation, usually has several contributing causes, and can be managed. Hormones DHT (dihydrotestosterone) DHT (dihydrotestosterone) is a potent androgen made from testosterone by the enzyme 5-alpha-reductase. It shapes the male genitals before birth and later acts on the prostate, skin and hair follicles.

Semen & ejaculation Ejaculate Ejaculate is the fluid released from the penis at orgasm: sperm suspended in seminal plasma made mostly by the seminal vesicles and prostate. As a verb, to ejaculate means to release it. Semen & ejaculation Ejaculatory abstinence Ejaculatory abstinence is the number of days since your last ejaculation. Longer gaps raise semen volume and sperm count, shorter gaps tend to give better sperm movement, and the WHO asks for 2 to 7 days before a semen test. Sperm & fertility Epididymis The epididymis is a tightly coiled tube lying along the back of each testis. Sperm pass through it after leaving the testis, and it is where they mature, gaining the ability to swim forwards and fertilise an egg, before being stored for ejaculation. Erections & performance Erectile dysfunction Erectile dysfunction (ED) is a persistent difficulty getting or keeping an erection firm enough for satisfying sex. It is common, becomes more likely with age, and can be an early warning sign of blood vessel or heart problems.

Supplements & nutrients Fenugreek Fenugreek (Trigonella foenum-graecum) is a culinary seed sold in extract form for testosterone and libido. A 2026 meta-analysis found a small increase in total testosterone, and trials of a standardised seed extract reported improved libido and sexual function in healthy men. Hormones Follicle-stimulating hormone (FSH) Follicle-stimulating hormone (FSH) is a pituitary hormone that drives sperm production in the testes. In men, a raised FSH level often signals that the sperm-making machinery is under strain and the brain is pushing harder to compensate. Hormones Free testosterone Free testosterone is the portion of testosterone in the blood that is not attached to any protein, so it can pass straight into tissues. It is only a few percent of the total, but it can tell a different story from total testosterone.

Hormones Hypogonadism Hypogonadism is when the testes do not make enough testosterone, sperm or both. In men it is diagnosed only when symptoms line up with repeatedly low morning testosterone results, never from a single blood test. Semen & ejaculation Hypospermia (low semen volume) Hypospermia means a semen volume below the normal reference range, currently under 1.4 mL on the World Health Organization's figures. It is different from a low sperm count, and a single low result often reflects collection or a short gap since ejaculating.

Erections & performance Kegel exercises for men Kegel exercises are repeated squeezes of the pelvic floor muscles to make them stronger and better controlled. In men, trials show they can improve erectile function and bladder control, and they may help with premature ejaculation.

Supplements & nutrients L-arginine L-arginine is an amino acid the body uses to make nitric oxide, which relaxes blood vessels during an erection. In a meta-analysis of 10 trials in men with mild to moderate erectile dysfunction, arginine improved erectile function compared with placebo or no treatment. Supplements & nutrients L-citrulline L-citrulline is an amino acid the body converts into L-arginine, raising nitric oxide production. In a study of 24 men with mild erectile dysfunction, one month of L-citrulline improved erection hardness, and it raises blood arginine more effectively than arginine itself. Erections & performance Libido Libido is your sex drive: how often and how strongly you want sex. It varies naturally between men and over a lifetime, and is shaped by hormones such as testosterone, mood, health, medicines and how your relationship is going. Hormones Luteinising hormone (LH) Luteinising hormone (LH) is a pituitary hormone that tells the testes to make testosterone. Measured alongside testosterone, it shows whether a low level starts in the testes themselves or in the brain. Supplements & nutrients Lycopene Lycopene is the red antioxidant pigment in tomatoes and watermelon. A 2025 meta-analysis found lycopene supplements improved sperm concentration, and trials have reported better sperm motility and shape in healthy young men and higher sperm counts in infertile men.

Supplements & nutrients Maca Maca (Lepidium meyenii) is an Andean root vegetable sold as a powder or extract for libido and fertility. In a 12-week trial of healthy men it improved sexual desire without changing testosterone, and men with mild erectile dysfunction reported better erectile scores. Sperm & fertility Male infertility Male infertility is when a problem with the man's reproductive system is the reason, or part of the reason, a couple cannot conceive. Infertility itself is defined as no clinical pregnancy after 12 months of regular, unprotected sex. Erections & performance Morning wood (nocturnal penile tumescence) Morning wood is an erection you wake up with. It's the tail end of sleep-related erections, called nocturnal penile tumescence, which happen during REM sleep in healthy men and are a rough sign that the erection system works.

Hormones Oestradiol in men Oestradiol is the main form of oestrogen, and men need it too. Most of a man's oestradiol is made by converting testosterone, and it helps regulate body fat and sexual function alongside testosterone. Sperm & fertility Oligozoospermia Oligozoospermia means fewer sperm in the ejaculate than the reference range. Using WHO reference values, that is a concentration below 16 million per millilitre or a total below 39 million sperm per ejaculate.

Erections & performance PDE5 inhibitors PDE5 inhibitors are prescription medicines, including sildenafil, tadalafil, vardenafil and avanafil, that treat erectile dysfunction by strengthening the penis's natural response to sexual stimulation. They need a prescriber and must never be combined with nitrate medicines. Erections & performance Pelvic floor The pelvic floor is a sling of muscles across the base of the pelvis. In men it supports the abdominal organs, helps control urine and bowels, and is active during sex, and training it can improve erections and bladder control. Erections & performance Performance anxiety Sexual performance anxiety is worry about how you'll perform in bed: whether you'll get hard, last long enough or satisfy a partner. It's common, and it can create the very erection and ejaculation problems it fears. Semen & ejaculation Pre-ejaculate Pre-ejaculate is the clear, slippery fluid that appears at the tip of the penis during arousal, before ejaculation. It comes mainly from the Cowper's glands and often contains no sperm, but studies have found moving sperm in some men's samples. Erections & performance Premature ejaculation Premature ejaculation (PE) means regularly ejaculating sooner than you want: within about a minute of penetration since your first sexual experiences, or after a bothersome drop to around three minutes or less, with little control and real distress. Hormones Prolactin Prolactin is a pituitary hormone best known for milk production, but men make it too. It surges after orgasm, and persistently high levels, called hyperprolactinaemia, can flatten sex drive and cause erection problems. Semen & ejaculation Prostate The prostate is a walnut-sized gland below the bladder that wraps around the urethra. It adds about a quarter of the fluid in semen, rich in zinc, citrate and PSA, the enzyme that thins semen after ejaculation.

Erections & performance Refractory period The refractory period is the recovery time after ejaculation during which a man can't get another erection or ejaculate again. It varies widely between men and occasions, and surprisingly little research has actually measured it. Semen & ejaculation Retrograde ejaculation Retrograde ejaculation is when semen travels backwards into the bladder at orgasm instead of out through the penis, because the bladder neck does not close. It causes little or no ejaculate and cloudy urine afterwards, and can affect fertility.

Supplements & nutrients Selenium Selenium is a trace mineral that contributes to normal spermatogenesis, the production of sperm. In a trial of subfertile men with low selenium status, supplements improved sperm motility. Food sources include Brazil nuts, fish and eggs, and high intakes carry safety risks. Sperm & fertility Semen analysis A semen analysis is a laboratory test of a semen sample that measures volume, sperm concentration, total count, motility and morphology. It is the first-line test of male fertility, and an abnormal result is usually repeated before any conclusions are drawn. Semen & ejaculation Semen volume Semen volume is the amount of fluid released in a single ejaculation. Most of it comes from the seminal vesicles and prostate rather than the testicles, and the World Health Organization's current lower reference limit is 1.4 mL. Supplements & nutrients Semen volume supplements Semen volume supplements are products that combine nutrients such as zinc, L-arginine and lycopene with herbs such as maca and ashwagandha. Research on these ingredients covers sperm quality, erections and hormones, and some studies have also measured semen volume. Semen & ejaculation Seminal plasma Seminal plasma is the fluid, non-cellular part of semen: secretions from the testes, epididymis, seminal vesicles, prostate and bulbourethral glands that carry, fuel and protect sperm. It makes up the great majority of every ejaculate. Semen & ejaculation Seminal vesicles The seminal vesicles are two small glands behind the bladder that produce most of the fluid in semen, about 65% of it, including fructose to fuel sperm and proteins that make semen briefly thicken after ejaculation. Hormones SHBG (sex hormone-binding globulin) SHBG (sex hormone-binding globulin) is a protein made by the liver that grips testosterone and oestradiol tightly in the blood. The more SHBG you have, the less of your testosterone is free to act on your tissues. Sperm & fertility Sperm concentration Sperm concentration is the number of sperm in each millilitre of semen, reported in millions per mL. The World Health Organization's 2021 lower reference limit is 16 million sperm per mL. Sperm & fertility Sperm count Sperm count is the total number of sperm in a single ejaculate, calculated by multiplying sperm concentration by semen volume. The World Health Organization's lower reference limit is 39 million sperm per ejaculate. Sperm & fertility Sperm DNA fragmentation Sperm DNA fragmentation is damage, in the form of breaks, to the genetic material carried inside sperm. It is reported as the percentage of sperm with damaged DNA, often called the DNA fragmentation index (DFI), and a standard semen analysis cannot detect it. Sperm & fertility Sperm morphology Sperm morphology is the percentage of sperm with a normal size and shape, judged under a microscope using strict criteria. The World Health Organization's 2021 lower reference limit is 4% normal forms, so most sperm in fertile men look imperfect. Sperm & fertility Sperm motility Sperm motility is the percentage of sperm in a sample that are moving, and how well they move. World Health Organization 2021 lower reference limits are 42% for total motility and 30% for progressive motility. Sperm & fertility Spermatogenesis Spermatogenesis is the process by which the testes turn stem cells into mature sperm. In humans it takes roughly 64 days from start to finish and is driven by the hormones FSH and testosterone.

Hormones Testosterone Testosterone is the main male sex hormone, made mostly in the testes on instructions from the brain. It drives sex drive, erections, sperm production, muscle and bone, and it is measured with a morning blood test. Hormones Testosterone replacement therapy (TRT) Testosterone replacement therapy (TRT) is prescribed testosterone, usually as a gel or injection, for men with confirmed hypogonadism. It can improve sex drive and erections, but it suppresses sperm production and needs regular monitoring. Supplements & nutrients Tongkat ali Tongkat ali (Eurycoma longifolia) is a Southeast Asian root sold for testosterone and libido. A 2022 meta-analysis of five randomised trials found it raised total testosterone, in both healthy men and men with low testosterone. Supplements & nutrients Tribulus terrestris Tribulus terrestris is a spiny plant with a long history as an aphrodisiac. In trials of men with mild to moderate erectile dysfunction, tribulus extract improved erectile function and sexual desire scores compared with placebo.

Sperm & fertility Varicocele A varicocele is a cluster of enlarged veins in the scrotum, similar to a varicose vein in the leg. It usually sits on the left side and is linked with poorer semen quality in some men, though many never have problems. Supplements & nutrients Vitamin D Vitamin D is a fat-soluble vitamin made in sunlit skin and found in a few foods. A meta-analysis of 17 trials found vitamin D supplements raised total testosterone in men, and very high doses can be harmful.

Supplements & nutrients Zinc Zinc is an essential mineral found in high concentrations in semen. It contributes to normal fertility and reproduction and to the maintenance of normal testosterone levels in the blood, and studies in infertile men have linked zinc supplements with better semen measures.