Zinc

Zinc deficiency can lower testosterone: Classic human work shows that restricting zinc intake in healthy young men markedly reduced serum testosterone over ~20 weeks; in marginally zinc-deficient older men, repletion increased testosterone over 3–6 months. Europe PMC

Biology that makes this plausible: Zinc is required for normal Leydig cell function (the testicular cells that make testosterone) and interacts with pathways driven by luteinizing hormone (LH) that stimulate steroidogenesis. Animal/cellular research (e.g., zinc transporters) supports a permissive role for zinc in testosterone synthesis. MDPI

Important nuance: Major guidelines for diagnosing/treating low testosterone do not list zinc as a primary therapy; rather, they emphasize confirming hypogonadism and treating underlying causes. Zinc matters if you’re zinc-deficient, not as a blanket fix. Oxford Academic

Confirm you actually need it

• Ask your clinician to evaluate morning testosterone (two separate days) and to assess zinc status (serum/plasma zinc plus diet/risk factors). (Low zinc can be subtle; see at-risk groups and testing caveats in the NIH fact sheet.) Oxford Academic

Choose an appropriate dose & form

• For general adequacy, adult men need ~11 mg/day; the Tolerable Upper Intake Level (UL) for adults is 40 mg/day elemental zinc (from food + supplements). Office of Dietary Supplements
• If documented deficiency is contributing to low T, short-term “therapeutic” dosing is sometimes used under medical supervision. A clinical review of men with hypogonadism describes zinc sulfate 220 mg (≈50 mg elemental zinc) twice daily for 1–4 months, then reassess. This exceeds the UL and should only be done with a clinician monitoring copper status and symptoms. Europe PMC
• Common supplemental forms (e.g., zinc gluconate, sulfate, acetate, picolinate) all provide elemental zinc; bioavailability also depends on your diet (phytates in whole grains/legumes can reduce absorption). Office of Dietary Supplements

Timing & absorption tips

• Take zinc with food if it upsets your stomach.
• Separate zinc from quinolone or tetracycline antibiotics (take the antibiotic ≥2 h before or 4–6 h after zinc). Separate from penicillamine by ≥1 h. Office of Dietary Supplements
• Diets very high in phytates (unsoaked legumes, unleavened whole grains) can reduce zinc absorption; traditional food prep (soaking, fermenting) helps. Office of Dietary Supplements

Duration & monitoring

• Re-check zinc, copper, and testosterone after ~8–12 weeks. If testosterone doesn’t improve—and zinc is now adequate—zinc is unlikely to help further, and standard hypogonadism management should be followed. Oxford Academic

Human depletion/repletion study (Nutrition, 1996)

• Zinc restriction in young men reduced testosterone; zinc repletion in marginally deficient older men increased testosterone after 3–6 months. This is the strongest direct human evidence linking zinc status and serum T. Europe PMC

Systematic review (2022)

• Summarized human and animal data: zinc deficiency is associated with lower testosterone, and supplementation can raise T primarily in deficient states; evidence is mixed in zinc-replete men. ScienceDirect

Short-term depletion data (AJCN)

• Controlled short-term dietary zinc depletion in young men affected serum testosterone and seminal parameters, underscoring sensitivity of reproductive hormones to zinc status. American Journal of Clinical Nutrition

Narrative/clinical reviews of hypogonadism & nutraceuticals

• Reviews highlight zinc as adjunctive when deficiency is present; zinc alone generally does not raise testosterone in men with normal zinc status. Translational Andrology and Urology