Quest Vitamins Synergistic Zinc provides zinc and copper which work synergistically and contribute to the normal function of the immune system and the protection of cells from oxidative stress. Zinc also contributes to the maintenance of normal hair, nails and skin, promoting general wound, ulceration and scar healing. It plays a role in fertility and reproduction, is needed for normal growth. Low levels of zinc may contribute to infertility, hormonal imbalances, poor wound healing and increased susceptibility to infection. Directions: Take one tablet daily with food.