Youtheory Collagen Liquid supplies 5,000mg of hydrolyzed collagen (per single serving) to help combat age-related collagen loss. Collagen is the most abundant protein in the body which naturally decreases with age. Collagen helps give structure to your skin, hair and nails, it is also necessary for the health of bones, skin, blood vessels and other organs. Low collagen levels can cause joint problems and skin elasticity loss.