What Does Zinc Do for Men? Testosterone, Fertility and Prostate

Zinc does for men what it does for everyone, and two sentences on the Great Britain register apply to men in particular: "Zinc contributes to the maintenance of normal testosterone levels in the blood" and "Zinc contributes to normal fertility and reproduction".¹ The NHS puts the amount at "9.5mg a day for men (aged 19 to 64 years)" and says: "Do not take more than 25mg of zinc supplements a day unless advised to by a doctor."² The testosterone trials are small: four young men whose testosterone fell when zinc was taken out of their diet, nine older men with low zinc whose levels rose on 30 mg a day with no placebo group, and no placebo-controlled trial showing a rise in men whose zinc was already normal.^{3, 4, 5} The one large fertility trial, in 2,370 couples, found no difference in live births or semen quality.⁶ This is the men's chapter of the Wellgard zinc guide, inside the vitamins and minerals guide.

What does zinc do for men?

The same as in any body. On the register, zinc contributes to the normal function of the immune system, the maintenance of normal skin, hair, nails and bones, normal cognitive function, normal fertility and reproduction and the maintenance of normal testosterone levels in the blood.¹ The NHS: zinc "helps with: making new cells and enzymes, processing carbohydrate, fat and protein in food, wound healing".² The men's part is the testes. In the classic description of deficiency, "hypogonadism in males" appears in severe and moderate deficiency, and the effect is "at the end organ level; the hypothalamic-pituitary axis is intact": the brain's signal is normal, the testes cannot answer it without zinc.⁷ The same review's causes of deficiency, alcoholism, malabsorption, kidney disease, penicillamine and some diuretics, map onto UK life as heavy drinkers, men with coeliac or Crohn's disease or after gut surgery, older men eating little, and vegans and vegetarians whose zinc comes bound to phytate.⁷ A man on a mixed diet typically reaches 9.5 mg; the signs of zinc deficiency have their own page.

Does zinc raise testosterone?

In men who were short of zinc, repletion restored it in small studies; in men whose zinc was normal, no placebo-controlled trial has shown a rise.

Four men, nine men, ten men, none with a placebo arm, and a 30 mg repletion dose above the NHS 25 mg supplement line: that is why the register sentence is a maintenance statement and nothing stronger may be said of a food supplement in Great Britain.¹ The NHS context: testosterone falls "at about 1% a year from around the age of 30 to 40", which "is unlikely to cause any problems in itself", while late-onset hypogonadism is "an uncommon and specific medical condition" a GP checks with a blood test.⁸ The same question for other ingredients: what does shilajit do for men and collagen for men.

Does zinc improve sperm or fertility?

The largest trial says no. In the Folic Acid and Zinc Supplementation Trial, the men of 2,370 couples planning fertility treatment took 5 mg of folic acid with 30 mg of zinc, or placebo, daily for six months. Live births were 34% on zinc and 35% on placebo (risk difference -0.9%, 95% CI -4.7% to 2.8%); no semen measure differed significantly; DNA fragmentation was slightly higher on zinc (29.7% against 27.2%), and nausea was more common (4% against 2%).⁶ Small trials pooled in a 2016 meta-analysis (20 studies, 2,600 infertile men) pointed the other way, with higher semen volume, motility and normal forms on zinc; the large trial did not confirm them.⁹ Zinc contributes to normal fertility and reproduction: that is the register's sentence, resting on the biology above rather than the trial record.¹ The NHS says see a GP if "you and your partner have been having regular sex without using contraception for over 1 year (or 6 months if your partner is 36 or over) and have not been able to get pregnant".¹⁰

Is zinc good for the prostate?

No wording exists. The register refused a "healthy prostate" claim for zinc, so no food supplement in Great Britain may make one, and no trial behind this page tested zinc for prostate size or symptoms, so "does zinc shrink the prostate?" has no answer.¹ The NHS says "See a GP if: you have difficulty peeing or need to pee more frequently", and to ask for an urgent appointment or call 111 for blood in your pee, pain when peeing or being unable to pee at all, because these symptoms "can sometimes be caused by other more serious conditions".¹¹

Does zinc help erectile function or libido?

No trial behind this page measured erections or sex drive after zinc, so "does zinc work like sildenafil?" has one answer: untested, and sildenafil is a medicine. The NHS says erectile dysfunction "is very common, particularly in men over 40", is "usually caused by stress, tiredness or drinking too much alcohol", and when it keeps happening may point to high blood pressure, high cholesterol, diabetes, depression, anxiety or hormone problems: "See a GP or go to a sexual health clinic if erection problems keep happening."¹²

Should men take 50 mg of zinc?

Not without a doctor. The NHS line is "Do not take more than 25mg of zinc supplements a day unless advised to by a doctor", with the reason: "Taking high doses of zinc reduces the amount of copper the body can absorb. This can lead to anaemia and weakening of the bones."² The UK Expert Group set the same 25 mg Safe Upper Level from the 50 mg dose at which copper and iron uptake changed in trials, so 50 mg a day is where the copper effect begins, twice the NHS line.¹³ The 30 mg doses above were trial doses under supervision.^{3, 6} A multivitamin and a separate zinc product can together pass 25 mg (how much zinc a day), so count the total from the elemental zinc figure on each label; zinc on an empty stomach commonly causes nausea, so take it with a meal. Can you take too much zinc and zinc and copper have the detail.

Is zinc good for men over 60?

Older men eating little are among those who run short, and the best-known trial was in older adults with low zinc: 50 adults aged 55 to 87 taking 45 mg a day for 12 months had a "significantly lower" incidence of infections than placebo; it has not been repeated at scale, and 45 mg is above the NHS supplement line.¹⁴ Zinc contributes to the normal function of the immune system; for a man over 60 the first question is whether his diet reaches 9.5 mg, answered below, and the colds evidence is on does zinc help with colds.¹

Which foods give a man 9.5 mg a day?

From the UK Composition of Foods Integrated Dataset, per 100 g as eaten: lean braised braising steak carries 9.5 mg, so one 100 g portion meets the day; cooked white crab meat 7.2 mg; roast lean lamb leg 5.2 mg; grilled chicken breast only 0.8 mg; raw oysters 59.2 mg.¹⁵ Worked to portions, 30 g of pumpkin seeds gives 2.0 mg, 30 g of cashews 1.8 mg, 120 g of boiled chickpeas 1.4 mg, two boiled eggs 1.3 mg, two slices of wholemeal bread 1.3 mg and 30 g of Cheddar 1.2 mg: a meat-free day of all six comes to 9.0 mg, and 40 g of porridge oats (0.9 mg) with 200 ml of semi-skimmed milk (0.8 mg) takes it past 10 mg.¹⁵ Foods high in zinc has the full list; the women's figures are on what does zinc do for a woman.

Frequently asked questions

What happens when a man takes zinc every day?

Within the NHS amounts, nothing he would notice. Above 25 mg a day for months, copper absorption falls, which the NHS says "can lead to anaemia and weakening of the bones".² Men on medicines should ask a pharmacist first.

Is zinc or magnesium better for testosterone?

Zinc carries the register sentence; magnesium does not. Neither has a placebo-controlled trial showing a rise in men whose levels were normal.^{1, 5} Can you take zinc and magnesium together covers the pairing.

Is zinc an aromatase inhibitor?

No human study behind this page shows that; the human record is the deficiency studies in the table.³

Which zinc is best for men?

No form has a trial in men that another lacks: the testosterone studies used gluconate and sulphate.^{3, 4} Read the elemental zinc figure on the label and take it apart from iron and calcium supplements; which type of zinc is best has the absorption study.

Sources

1. Great Britain nutrition and health claims register. gov.uk.
2. NHS. Vitamins and minerals: others, including zinc. nhs.uk.
3. Prasad AS, et al. Zinc status and serum testosterone levels of healthy adults. Nutrition, 1996. PubMed 8875519.
4. Kilic M, et al. The effect of exhaustion exercise on thyroid hormones and testosterone levels of elite athletes receiving oral zinc. Neuroendocrinology Letters, 2006. PubMed 16648789.
5. Te L, et al. Correlation between serum zinc and testosterone: a systematic review. Journal of Trace Elements in Medicine and Biology, 2023. PubMed 36577241.
6. Schisterman EF, et al. Effect of folic acid and zinc supplementation in men on semen quality and live birth among couples undergoing infertility treatment. JAMA, 2020. PubMed 31910279.
7. Prasad AS. Clinical manifestations of zinc deficiency. Annual Review of Nutrition, 1985. PubMed 3896271.
8. NHS. The "male menopause". nhs.uk.
9. Zhao J, et al. Zinc levels in seminal plasma and their correlation with male infertility: a systematic review and meta-analysis. Scientific Reports, 2016. PubMed 26932683.
10. NHS. Low sperm count. nhs.uk.
11. NHS. Enlarged prostate. nhs.uk.
12. NHS. Erectile dysfunction (impotence). nhs.uk.
13. Expert Group on Vitamins and Minerals. Safe Upper Levels for Vitamins and Minerals, 2003. UK Government Web Archive.
14. Prasad AS, et al. Zinc supplementation decreases incidence of infections in the elderly. American Journal of Clinical Nutrition, 2007. PubMed 17344507.
15. Composition of Foods Integrated Dataset (CoFID), 2021, table 1.4. gov.uk.

This article is general information, not medical advice.