Glutathione is essential for the immune system's proper functioning and is vital in building and repairing tissue. It acts as an important antioxidant, which helps protect your body from damage to cells caused by free radicals. It also decreases the melanin (pigmentation) in your skin, but has also been found to decrease wrinkles and increase skin elasticity. Glutathione works on the skin pigment production by inhibiting tyrosinase, an enzyme involved in making melanin.