As the most abundant protein in the body, collagen plays a key role in maintaining healthy-looking skin, hair and nails, joints and bone health, and can help build muscle mass and support an active lifestyle.* It starts to decline between ages 18-29. By 40, we may lose about 1% per year.* This may lead to weaker and more brittle hair and nails, less mobility, a loss of skin elasticity, and more visible fine lines and wrinkles.*