Taking daily collagen supplements can rejuvenate the skin by boosting elasticity and hydration or moisture - but it won't stop wrinkles, says a new scientific review. Experts looked at the available evidence and say they are highly confident that collagen pills or powder provide "some legitimate" skin gains if taken over time but are no quick fix. The supplements may also ease wear and tear, arthritis joint pain and stiffness, according to the results from 113 trials involving nearly 8,000 people. Collagen is a type of protein made naturally in the body but that declines with age. It supports and strengthens skin, nails, bones and connective tissues, including tendons and cartilage. From early adulthood onwards, the body produces less collagen and existing collagen breaks down at a slightly faster rate. Smoking and sun damage make this worse.…