Zinc is an essential mineral involved in hundreds of enzymatic processes in the body, including testosterone synthesis. The relationship between zinc and testosterone is real and well-established, but it's more nuanced than the marketing for zinc supplements suggests.
Zinc's role in testosterone: zinc is required for the function of 5-alpha reductase and aromatase - enzymes involved in testosterone metabolism. Zinc deficiency is strongly associated with reduced testosterone levels in multiple studies. Correcting zinc deficiency reliably restores testosterone to normal ranges. This is the legitimate scientific basis for zinc-testosterone claims.
The nuance: zinc supplementation only raises testosterone when you're deficient. If your zinc levels are already adequate, supplementing additional zinc doesn't further increase testosterone. Most healthy Australians with varied diets aren't zinc deficient, which means the dramatic testosterone-boosting claims of zinc supplements are irrelevant for them. Athletes are at higher risk of zinc deficiency due to increased loss through sweat and high metabolic demand, which may make supplementation more relevant in this population. Dietary zinc sources: red meat, shellfish (particularly oysters, which are extremely zinc-rich), poultry, nuts, and legumes. If you eat red meat regularly and have a varied diet, zinc deficiency is unlikely. If you're vegetarian, vegan, or sweat heavily, consider 15-30mg of zinc picolinate or citrate daily.