Does zinc raise testosterone?

The EU-authorised claim says it contributes to maintaining normal blood testosterone levels. Maintaining is not raising: in a man with normal levels and enough intake, there is no evidence that adding zinc increases them. Where it does change something is when you start from a real deficiency.

How much zinc should you take a day?

The EU labelling reference value is 10 mg. Many supplements carry 15 or 25 mg per capsule, and together with a multivitamin it is easy to double or triple the reference without noticing. More is not better: at high sustained doses zinc interferes with copper absorption.

What is the best form of zinc?

Bisglycinate, picolinate, citrate and gluconate are absorbed better than oxide, and at these prices the difference per tub is a few euros. What matters is still elemental zinc per serving, which the label declares with its percentage of the reference value.

Does zinc prevent colds?

EU regulation allows saying it contributes to normal immune system function, which is a statement about maintaining function, not avoiding infections. The studies that look at cold duration use lozenges at high doses in the first hours of symptoms, which is a different use from the daily supplement.

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Zinc · Moderate evidence

What zinc is for and how much to take

The short answer. Zinc is involved in hundreds of enzymes, and EU regulation recognises its role in the immune system, protecting cells from oxidative damage and maintaining normal testosterone levels. That last phrase is the one that sells tubs, and it is worth reading in full: maintaining normal levels is not raising them. In someone with enough intake already, adding zinc changes nothing, and overdoing it has its own cost.

There are studies in favour, but few, with small samples or measuring markers instead of outcomes. No figure on this page is attributed to a specific product: the effect belongs to the ingredient and every number carries its source next to it.

01 What it does and how much

Each row is a measured effect, with the figure the study gives and the source number. Where the evidence gives no figure, the column says so instead of making up a percentage.

Effects of zinc with their source
Effect	How much	Detail
EU daily reference value	10 mg	The NRV shown on labels. Many tubs carry 25 mg per capsule, which is two and a half times that reference. [1]
Functions authorised in the EU	immunity, cells and normal testosterone	The authorised claim speaks of MAINTAINING normal blood testosterone levels. In someone with normal levels, maintaining them means exactly changing nothing. [2]
Effect without deficiency	none demonstrated	It is the general rule for micronutrients and it holds here: without a prior deficiency there is no performance gain. [3]
Sustained excess	interferes with copper	High doses sustained for months compete with copper absorption. It is the practical reason not to stack several tubs containing zinc. [1]

02 How to take it

Dose. Around the 10 mg reference value, counting what the diet already provides.
When. With food: on an empty stomach it disagrees with many people.
How long before you notice it. If it corrects a low intake, weeks.

Details that change the result

Meat, seafood, legumes, nuts and seeds provide zinc every day. Vegan diets are more at risk of falling short because of phytates in wholegrains.
Add up the total: a multivitamin, a ZMA and a zinc tub can reach three or four times the reference value without anyone noticing.
Bisglycinate, picolinate and citrate are absorbed better than oxide, and the price difference is small.
Zinc lozenges for colds are a different product at different doses; this page is about the daily supplement.

03 When it makes sense and when it does not

Worth it if

Vegan or vegetarian diet with few legumes and few nuts.
Demonstrated low intake or medical advice.
High losses from very heavy, prolonged sweating.

Not worth it if

To raise testosterone when it is normal: the authorised claim says maintain, not increase.
At high doses indefinitely, because of copper.
On top of other tubs that already contain it, without doing the sum.

04 Sources

Every figure above comes from here. They are position stands from scientific societies, meta-analyses and peer-reviewed reviews: if a claim cannot hang from one of these lines, it is not on the page. References are cited in their original form.

Reglamento (UE) 1169/2011, Anexo XIII: valores de referencia de nutrientes. Zinc, 10 mg. https://eur-lex.europa.eu/legal-content/ES/TXT/?uri=CELEX%3A32011R1169
Reglamento (UE) 432/2012: declaraciones autorizadas. El zinc contribuye al funcionamiento normal del sistema inmunitario, a la proteccion de las celulas frente al dano oxidativo y al mantenimiento de niveles normales de testosterona en sangre. https://eur-lex.europa.eu/legal-content/ES/TXT/?uri=CELEX%3A32012R0432
Kerksick CM et al. ISSN exercise & sports nutrition review update. J Int Soc Sports Nutr. 2018;15:38. Sin deficit previo, los micronutrientes no mejoran el rendimiento. doi:10.1186/s12970-018-0242-y

This is not medical advice. It is what some studies say about an ingredient, not a protocol for you. With an illness, medication or pregnancy involved, the decision belongs to a healthcare professional who knows you.

Questions about zinc

Answered with the data on this page

Does zinc raise testosterone?: The EU-authorised claim says it contributes to maintaining normal blood testosterone levels. Maintaining is not raising: in a man with normal levels and enough intake, there is no evidence that adding zinc increases them. Where it does change something is when you start from a real deficiency.
How much zinc should you take a day?: The EU labelling reference value is 10 mg. Many supplements carry 15 or 25 mg per capsule, and together with a multivitamin it is easy to double or triple the reference without noticing. More is not better: at high sustained doses zinc interferes with copper absorption.
What is the best form of zinc?: Bisglycinate, picolinate, citrate and gluconate are absorbed better than oxide, and at these prices the difference per tub is a few euros. What matters is still elemental zinc per serving, which the label declares with its percentage of the reference value.
Does zinc prevent colds?: EU regulation allows saying it contributes to normal immune system function, which is a statement about maintaining function, not avoiding infections. The studies that look at cold duration use lozenges at high doses in the first hours of symptoms, which is a different use from the daily supplement.

And now, which to buy

Prices, kept apart from the evidence

This page explains what zinc does and deliberately names no brand. The comparison is the other half: 81 products from 12 stores from €0.022 per capsule, sorted by price and by how verifiable their certification is.

See the zinc comparison

Other guides

What each supplement does, with its sources