Weak evidence · Vitamins & minerals
Zinc
Immune function, only relevant when deficient
Weak evidence
Mostly small studies, animal trials or conflicting results. Not worth your money as a foundation.
The evidence that extra zinc does anything for healthy athletes is weak. For colds, the 2024 Cochrane review found the evidence insufficient for a recommendation. Only lozenges with more than 75 mg of zinc per day shortened a cold by an average of 33% in an analysis of seven trials, but that dose is far above the upper limit for long-term use.
- Dosage
- No more than 25 mg per day in total (EFSA upper limit)
- Timing
- —
- Approx. price
- €3–8 per month
Watch out
The EFSA upper limit for adults is 25 mg per day; the US FDA uses 40 mg. Too much zinc is associated with a copper deficiency.
Frequently asked questions about supplements
How much Zinc per day?
No more than 25 mg per day in total (EFSA upper limit)
Does Zinc really work?
Weak evidence. Mostly small studies, animal trials or conflicting results. Not worth your money as a foundation.
What does Zinc cost?
€3–8 per month
Basics first, then the tub
Supplements are called supplements because they add to something. Sleep, a protein intake that hits your protein calculator , a programme where you lift progressively heavier and enough food together do a hundred times more than the best-researched item on this list. Once those are in place, creatine, caffeine and vitamin D in winter are the three you can spend money on with a clear conscience — for less than ten euros a month combined.
Sources
- Nault D et al. (2024). Zinc for prevention and treatment of the common cold. Cochrane Database Syst Rev CD014914. (Cochrane review)
- Hemilä H, Chalker E (2024). Shortcomings in the Cochrane review on zinc for the common cold (2024). Front Med 11:1470004. (re-analysis)
- EFSA (2024). Summary of tolerable upper intake levels (UL summary report). (regulatory report)
More supplements in this category
Last updated: October 2026
This page summarises scientific research and is not medical advice. If you take medication, are pregnant or have a liver, kidney or thyroid condition, discuss supplements with your doctor or pharmacist — even the innocent-looking ones.
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