Should you take collagen?

WOULD YOU pay £40 ($53) for some powder made from the ground-up, chemically processed skin, bones and connective tissues of cows or fish? Marketed that way, perhaps not. But stick it in a bottle labelled supplementary collagen, and things might start to look more appealing. Collagen supplements are in vogue, taken both by athletes (who hope for stronger, more injury-resistant joints and ligaments) and the beauty-conscious (for its alleged ability to smooth wrinkled skin and restore lustre to hair). How much good they do, though, remains unclear.