@naturaloptionske: One drop in the morning and evening is all you need! Some By Mi Galactomyces Pure Vitamin C Glow Serum is made with 3% Pure Vitamin C and 75% Galactomyces ferment filtrate. The gentle amount of Vitamin C helps brighten skin and Galactomyces is also known to moisturize, smooth skin texture and boost elasticity. How to use After toner, apply all over skin. * To maximize effectiveness and prevent oxidation, store the product in the refrigerator or a cool, dark place.