Is zinc important for testosterone in men?

Zinc deficiency is associated with reduced testosterone in men, and zinc repletion in deficient men produces measurable testosterone increases, but zinc supplementation in men with normal zinc status does not raise testosterone, making zinc relevant as a deficiency correction rather than a testosterone booster for the already-replete (Prasad et al., Nutrition, 199600232-2)).

Zinc is a cofactor in testosterone synthesis (5-alpha reductase and 17β-hydroxysteroid dehydrogenase), and in men with dietary zinc deficiency (more common in vegetarians, heavy exercisers with high sweat loss, and men with significant alcohol use), serum testosterone can be meaningfully suppressed. Testing serum zinc is imprecise (zinc is primarily intracellular), but a dietary audit looking for zinc-rich food frequency (meat, shellfish, eggs, pumpkin seeds) plus symptoms of deficiency (poor wound healing, taste alterations, immune issues) is useful clinical context.

Honesty Scale: Solid (1) for zinc repletion in deficient men increasing testosterone. Unsupported (5) for zinc supplementation raising testosterone in zinc-replete men.

What to do: Assess your dietary zinc intake before supplementing. If your diet is low in animal protein (or you are vegetarian), 15–25 mg elemental zinc daily from a well-absorbed form (zinc picolinate, gluconate) is a reasonable correction. Do not exceed 40 mg/day long-term, zinc toxicity impairs copper absorption and causes its own set of problems.

For the full picture, read The Supplementation Deep Dive