Zinc
Contributes to the normal function of the immune system and to the protection of cells from oxidative stress.
Also known as Zinc Picolinate, Zinc Citrate, Zinc Gluconate, Zinc Bisglycinate, Zinc Carnosine
Common doses
15-30 mg
Best timing
Morning
Food
Take with food
Interactions
6 known
Zinc is an essential trace mineral involved in over 300 enzymatic reactions and required for immune function, wound healing, protein synthesis, and DNA repair. It is the second most abundant trace mineral in the body after iron, yet the body has no specialised zinc storage system, meaning consistent dietary intake is important.
Zinc deficiency is more common than many people realise, particularly among vegetarians (plant-based zinc is less bioavailable due to phytates), older adults, and people with GI conditions that affect absorption. Even mild zinc insufficiency can impair immune function and slow wound healing.
Zinc is one of the most popular supplements for immune support, especially during cold and flu season. The evidence for zinc lozenges reducing cold duration is actually quite good, though the form and dose matter significantly.
Key benefits
Immune function
Zinc contributes to the normal function of the immune system. Zinc lozenges taken within 24 hours of cold onset may reduce duration by 1-2 days.
Skin and wound healing
Zinc contributes to the maintenance of normal skin. It is involved in collagen synthesis, inflammatory response, and cell membrane repair.
Testosterone
Zinc contributes to the maintenance of normal serum testosterone concentrations. Zinc deficiency is associated with reduced testosterone production.
Protein synthesis
Zinc contributes to normal protein synthesis and normal DNA synthesis. It is a structural component of over 2,000 transcription factors.
Available forms
Zinc Picolinate
One of the best-absorbed forms. Well-tolerated. A good general-purpose zinc supplement.
Zinc Bisglycinate
Chelated with glycine. Excellent absorption and very gentle on the stomach.
Zinc Citrate
Good absorption. Slightly metallic taste. Affordable and widely available.
Zinc Gluconate
The form used in most zinc lozenges for cold treatment. Moderate absorption.
Zinc Oxide
Cheapest form. Poorly absorbed orally. Primarily used in topical applications (sunscreen, diaper rash cream).
Food sources
- Oysters (highest food source)
- Red meat (beef, lamb)
- Poultry
- Pumpkin seeds
- Chickpeas and lentils
- Cashews
Signs of deficiency
- Frequent colds and infections
- Slow wound healing
- Loss of taste or smell
- Hair loss
- White spots on fingernails
- Poor appetite
Upper intake limit
40 mg/day elemental zinc (NIH). Long-term supplementation above 30 mg/day should include 1-2 mg copper to prevent copper deficiency.
Research summary
Strong evidence for immune function and reducing cold duration (zinc lozenges). Good evidence for wound healing and testosterone maintenance in deficient individuals. The zinc-copper interaction is well-established: chronic zinc supplementation depletes copper. Include copper if supplementing long-term.
Known interactions (6)
Check your full stack
for interactions.
See what competes, what combines well, and when to take everything. Every interaction cites a published source.
Stack
6 supplements
Stack review
1 flagZinc and Iron compete for the same absorption pathway. Take at least 2 hours apart.
Supplements
This information is for educational purposes only. It is not medical advice and does not diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional.