Zinc: Your Cold-Fighting Ally?
An essential mineral that may shorten colds when used correctly, but won't prevent illness or work miracles for most healthy people.
Mar 24, 2025
What is Zinc?
Zinc is an essential mineral your body needs for immune function, enzyme activity, wound healing, and DNA synthesis. You'll find it in meat, shellfish, legumes, and fortified grains. It's also a common ingredient in cold lozenges, multivitamins, and immune supplements. But does it actually work when you're fighting off the sniffles? The Science Behind Zinc
Efficacy in Clinical Trials: 6/10
Zinc's most popular use is as a cold remedy, and the evidence is mixed but promising:
Cold Duration: A 2013 Cochrane review found that zinc acetate or gluconate lozenges taken within 24 hours of symptoms can shorten colds by about 1-2 days. Not earth-shattering, but definitely noticeable.
Prevention: Daily zinc supplementation doesn't appear to prevent colds in healthy people, despite what supplement companies might claim.
Deficiency Treatment: Zinc supplementation clearly works for people with deficiencies, which are more common in older adults, vegetarians, and those with digestive disorders.
Expert Consensus: 7/10
Health professionals give zinc a cautious thumbs-up:
The NIH and CDC acknowledge zinc can reduce cold duration, though it's not formally recommended like vaccines or antivirals.
Most experts don't support high-dose daily zinc for healthy people due to side effects and potential copper deficiency with long-term use.
Zinc is standard treatment for deficiency, childhood diarrhea in developing countries, and certain skin conditions.
Benefit to Average Consumer: 6/10
For the typical supplement shopper:
If you're deficient, zinc supplements can genuinely improve immune function and wound healing.
If your levels are normal, benefits are modest – you might shorten a cold slightly with the right form at the right time.
Too much zinc (especially over 40 mg/day long-term) can cause nausea, upset stomach, metallic taste, and copper deficiency.
Important safety note: Avoid zinc nasal sprays, which have been linked to permanent loss of smell.
The Verdict
Legitimate, but not miraculous. Zinc has science-backed benefits for reducing cold duration when used early and correctly. It's essential for immune health and clearly helpful in cases of deficiency. But it's not a cold cure or daily shield – and proper dosing matters.
Overall Score: 6/10
References:
Hemilä H, Chalker E. (2013). Zinc for the common cold – a Cochrane review update. https://pubmed.ncbi.nlm.nih.gov/22592666/
NIH Office of Dietary Supplements – Zinc Fact Sheet for Health Professionals.
Singh M, Das RR. (2011). Zinc for the common cold. Cochrane Database Syst Rev.+
Prasad AS. (2008). Zinc in human health: effect of zinc on immune cells. Mol Med. https://pubmed.ncbi.nlm.nih.gov/18385818/