Zinc
MineralAlso known as: Zn · Zinc picolinate · Zinc glycinate · Zinc gluconate
An essential trace mineral involved in immune function, testosterone production, wound healing, and hundreds of enzymatic reactions. Deficiency is common, especially in athletes.
The bottom line
Zinc has genuine support for shortening respiratory infections and for male fertility markers, which puts it ahead of many trendier supplements — though, as everywhere here, most tracked claims (265 of 284) remain unproven. The big practical caveat is dose: above ~40 mg/day long-term it depletes copper, so more is not better and it's easy to overshoot by stacking products. Best used short-term or at modest doses rather than as an open-ended daily megadose.
Our plain-language reading of the expert claims and research on this page. Not medical advice.
How expert claims hold up
298 of 309 claims assessed23 of 298 assessed claims supported or partially supported by published research
Expert Consensus
Dose divergence: Experts recommend different amounts (50milligrams, 15–30milligrams, 75–92milligrams, 40milligrams, 15 to 30milligrams, 15 to 25milligrams, 5 to 10milligrams). Check the Stack & Timing tab for study-backed dosing ranges.
Evidence Summary
The body of evidence on zinc supplementation is broad, covering immune function, reproductive health, wound healing, metabolic conditions, and more. Across multiple meta-analyses and systematic reviews in this dataset, zinc consistently emerges as a mineral with meaningful physiological roles, and supplementation shows measurable benefits in several specific contexts — particularly for male fertility parameters, immune support, dysmenorrhea (painful periods), and blood sugar regulation in prediabetes. However, the strength and consistency of findings varies considerably by health outcome, and the evidence base is stronger for some applications than others.
Read full evidence summary →Top studies
Dietary supplements for dysmenorrhoea.
Dietary supplements for dysmenorrhoea.
Micronutrient Supplementation and Fortification Interventions on Health and Development Outcomes among Children Under-Five in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis.
Micronutrient Supplementation and Fortification Interventions on Health and Development Outcomes among Children Under-Five in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis.
Expert Mentions
All 309 mentions
“Long-term high-dose zinc supplementation without copper monitoring can deplete copper and create new problems.”
Long-term high-dose zinc supplementation without copper monitoring can deplete copper and create new problems.
None of the 10 provided studies directly address the relationship between long-term high-dose zinc supplementation and copper depletion. The retrieved literature covers topics such as zinc for HPV cle…
“high-dose zinc supplementation — above 40 milligrams per day long-term — can actually deplete copper because zinc and copper compete for absorption.”
High-dose zinc supplementation above 40 milligrams per day long-term can deplete copper because zinc and copper compete for absorption.
None of the 10 listed studies directly address the zinc-copper competition mechanism or the specific threshold of 40 mg/day zinc causing copper depletion. The studies cover zinc in prediabetes (PMID 3…
Safety, interactions & who should avoid Zinc
caution_warranted
Zinc is generally considered safe at moderate supplementation doses, but high doses over time can interfere with copper absorption and potentially impair immune function — the very outcome supplementation is often intended to support. The reviewed studies do not provide detailed adverse event data, so caution is warranted at the higher end of commonly recommended dose ranges.
Doses above 40 mg per day long-term are associated with copper depletion due to competitive absorption, which can impair immune function and neurological health. Gastrointestinal side effects (nausea, stomach upset) are common when zinc is taken without food. The reviewed ALS literature cautions against unsupported high-dose zinc use in neurological contexts. Zinc supplementation in populations with adequate dietary intake may confer less benefit and could increase risk of imbalance.
Who should avoid it
Individuals with Wilson's disease (copper metabolism disorder) should use zinc only under medical supervision, as it can further reduce copper levels. Those with kidney disease should consult a healthcare provider before supplementing, as impaired excretion may increase toxicity risk. Pregnant and breastfeeding individuals should not exceed established upper tolerable intake levels without medical guidance. People already meeting zinc needs through diet may not benefit and could be at higher risk of adverse effects from supplementation.
Known interactions
- ·Zinc competes with copper for intestinal absorption; long-term supplementation above ~25–40 mg/day may cause copper deficiency
- ·Zinc may reduce the absorption of certain antibiotics (e.g., fluoroquinolones, tetracyclines) when taken simultaneously
- ·High-dose zinc may interfere with iron absorption, relevant when both are supplemented (as noted in the oral iron supplementation meta-analysis context)
- ·Zinc and calcium-rich foods or supplements may reduce zinc bioavailability when taken together
Pregnancy & breastfeeding
Our sources specifically flag pregnancy or breastfeeding considerations for Zinc — see the cautions above.
We don’t assign pregnancy-safety ratings. Many supplements lack adequate safety data in pregnancy and breastfeeding, and the absence of a warning here does not mean a supplement is safe to take. Don’t start, stop, or continue any supplement while pregnant or nursing without your OB-GYN or midwife.
Read: Supplements during pregnancy & breastfeeding →This is educational information only. Consult a healthcare provider before starting any supplement.
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Key findings
- ·Zinc supplementation shows evidence of benefit for sperm parameters and some reproductive outcomes in men, supported by a strong-quality meta-analysis on dietary supplements and male infertility.
- ·Multiple strong-quality meta-analyses support zinc's role in immune function, including reducing risk or severity of respiratory tract infections in adults.
- ·A strong-quality meta-analysis found zinc supplementation may help manage primary dysmenorrhea (menstrual pain), suggesting anti-inflammatory or hormonal mechanisms.
Evidence gaps
- ·Most studies do not rigorously control for baseline zinc status, making it unclear whether benefits apply to people who are already zinc-sufficient versus those who are deficient.
- ·Optimal dosing, timing, and form of zinc supplementation (e.g., picolinate vs. oxide vs. bisglycinate) are not well-established in the reviewed literature — one RCT found no benefit of folic acid and zinc for live birth rates despite improving some sperm parameters.
- ·Long-term safety and efficacy data for sustained zinc supplementation at commonly used doses (15–30 mg/day) in healthy adults is limited, and potential interactions with copper absorption are not well-addressed in this dataset.