Zinc
Also: zinc citrate · zinc gluconate · zinc picolinate · zinc oxide · ZMA
Take if deficient — well-established role in testosterone and sperm production; megadosing won't push T above normal in already-replete men.
Testosterone & hormonal load
Zinc is an essential cofactor for testosterone biosynthesis in Leydig cells and for aromatase regulation. Controlled human studies demonstrate that dietary zinc restriction leads to a 75% reduction in serum testosterone within 20 weeks in young men, and zinc supplementation in deficient men normalizes testosterone levels. However, supraphysiological zinc intake in replete men does not further elevate testosterone. Zinc also plays a key role in sperm morphology and motility.
Found in.
Two jurisdictions, two different verdicts.
Permitted in food supplements with established upper intake levels (25 mg/day for adults, EFSA). Zinc oxide permitted in cosmetics including sunscreen.
Generally Recognized as Safe (GRAS) as a dietary supplement. Zinc oxide is Category I (safe and effective) for sunscreen use. Tolerable upper intake level: 40 mg/day (NIH).
The receipts.
- [01]Prasad et al. 1996 — Zinc deficiency and testosterone (PubMed)pubmed.ncbi.nlm.nih.gov/8875519/
- [02]Fallah et al. 2018 — Zinc is an essential element for male fertility (PubMed)pubmed.ncbi.nlm.nih.gov/30009140/
- [03]NIH Office of Dietary Supplements — Zinc Fact Sheetods.od.nih.gov/factsheets/Zinc-HealthProfessional/
Find Zinc before it finds you.
Point the camera at any barcode. Mangood reads the ingredient list and tells you, in one tap, whether Zinc is hiding in the bottle in your hand.