tuneTypical Dose
15–30 mg
Vitamin
Zinc
Zinc (Zn, element 30)
Evidence TierAWADA NOT PROHIBITED
watchEffect Window
Acute (cold treatment) to weeks (acne, hormonal normalization).
check_circleCompliance
WADA NOT PROHIBITED
Overview
Clinical Summary
Zinc is an essential mineral for immune function, wound healing, and many enzymes. It is used to correct deficiency and to support immune resilience, and skin and reproductive biomarkers in low status states.
Correcting deficiency improves immune function, taste, growth, and wound healing. Evidence supports reduced common cold duration when adequately dosed zinc lozenges are started early, though effects depend on formulation, elemental zinc dose, and avoiding poorly ionizing products. Zinc can also reduce primary dysmenorrhea pain in some protocols, while testosterone and sperm benefits remain most defensible in zinc-deficient men. Excess zinc can cause nausea and copper deficiency, limiting net benefit.
Cofactor for over 300 enzymes including superoxide dismutase and RNA polymerases; regulates immune function (T-cells), protein synthesis, and androgen metabolism; weakly inhibits 5-alpha-reductase.
Outcomes
What This Is Expected To Influence
Primary Outcomes
- Reduces common cold duration by ~33% (lozenges at onset)
- Corrects zinc-deficiency-related immune dysfunction
- Improves inflammatory acne severity
Secondary Outcomes
- Normalizes testosterone in zinc-deficient men
- NMDA receptor modulation
Safety
Contraindications and Interactions
Contraindications
- None absolute at standard doses
Side effects
- Stomach pain
- Nausea (especially on an empty stomach)
- Vomiting
- Diarrhea
- Headache
- Metallic taste
Interactions
- Cephalexin (Possible/Moderate) - Zinc supplements can bind with cephalexin and decrease its absorption and effectiveness when they are administered together.
- Tetracycline antibiotics (Probable/Moderate) - Zinc can chelate tetracyclines and reduce antibiotic absorption; separate doses by at least 2 hours.
- Fluoroquinolone antibiotics (Probable/Moderate) - Zinc can chelate fluoroquinolones and reduce antibiotic absorption; separate doses by at least 2 hours.
- Penicillamine (Probable/Moderate) - Zinc may reduce penicillamine absorption and effectiveness; separate doses by at least 2 hours.
- Calcium (Possible/Moderate) - Calcium supplements may reduce the absorption of zinc when they are administered together and potentially reduce zinc effectiveness.
- Caffeine (Possible/Moderate) - Taking a zinc supplement with black coffee may reduce the absorption of zinc.
- Manganese (Possible/Moderate) - Zinc supplementation may enhance the absorption of supplemental manganese.
- Bisphosphonates (Theoretical/Moderate) - Theoretically, zinc supplements can bind with bisphosphonates and reduce their absorption and effectiveness when they are administered together.
- Iron (Probable/Minor) - Coadministration of iron and zinc may reduce the absorption of both supplements.
- Copper (Probable/Moderate) - Chronic higher-dose zinc can reduce copper absorption via metallothionein and increase copper deficiency risk; co-supplement ~1-2 mg copper with 15-30 mg zinc for long-term use.
Avoid if
- None specific at standard doses (15–30 mg)
- Pregnancy or breastfeeding without clinician guidance
- Concurrent use of interacting medications without dose separation (for example cephalexin, tetracyclines, fluoroquinolones, penicillamine, or bisphosphonates)
Evidence
Study-level References
zinc-SRC-001Meta-analysis
Sourceopen_in_newHemila H. Zinc lozenges and the common cold: a meta-analysis comparing zinc acetate and zinc gluconate, and the role of zinc dosage. JRSM Open. 2017;8(5):2054270417694291. doi:10.1177/2054270417694291. PMID:28515951.
Population: Participants with naturally acquired common colds from seven placebo-controlled randomized trials
Dose protocol: Zinc lozenges (zinc acetate or zinc gluconate) at doses ranging from 80-207 mg/day
Key findings: Zinc lozenges shortened the duration of colds by 33%.
Paper content
This meta-analysis of seven randomized placebo-controlled trials (575 participants) compared the efficacy of zinc acetate and zinc gluconate lozenges for common cold treatment. Zinc lozenges overall shortened cold duration by 33%, with no statistically significant difference between zinc acetate (40%) and zinc gluconate (28%) or between low-dose (80-92 mg/day) and high-dose (192-207 mg/day) regimens. The findings suggest properly composed zinc gluconate lozenges may be as effective as zinc acetate lozenges for cold treatment.
zinc-SRC-002Systematic review and meta-analysis of randomized controlled trials
Sourceopen_in_newHsu TJ, Hsieh RH, Huang CH, et al. Efficacy of Zinc Supplementation in the Management of Primary Dysmenorrhea: A Systematic Review and Meta-Analysis. Nutrients. 2024;16(23):4116. doi:10.3390/nu16234116. PMID:39683510.
Population: Women with primary dysmenorrhea enrolled in six randomized controlled trials.
Dose protocol: Oral elemental zinc from 7 mg/day and higher across six randomized dysmenorrhea trials
Key findings: Significantly reduced menstrual pain severity with no clear excess in adverse events versus placebo.
Notes: Stronger effects were seen with longer intervention duration rather than simply higher dose.
Paper content
This 2024 meta-analysis adds a legitimate newer use case for zinc beyond cold lozenges and deficiency correction. Across six randomized trials in primary dysmenorrhea, zinc supplementation significantly reduced pain severity, with stronger effects in interventions lasting at least 8 weeks and no clear safety penalty versus placebo. The meta-regression favored duration over higher dose, which helps keep dosing language conservative.