Collagen supplementation helps increase skin flexibility and hydration, which helps to smooth wrinkles and increase tone and firmness of the skin. Collagen has been studied to help smooth cellulite, too, by improving skin elasticity. Daily collagen supplementation is commonly used to help strengthen tendons, joints, and ligaments. Research has shown (especially with Type II Collagen) that collagen can alleviate joint pain, stiffness and inflammation, as well as help improve flexibility. Collagen protein contains the amino acids essential for the human body to repair and rebuild damaged muscle and connective tissue, leading to increased lean muscle and improved metabolism. Adding additional collagen has been shown to help grow stronger, longer, healthier hair and nails. Strengthened roots and faster nail growth are common with collagen supplementation. Collagen contains many essential amino acids, such as glutamine, which is the most abundant free amino acid in the body. Glutamine and alanine help promote optimal gut and digestive health.