Marianne Macrita Sena

High-quality studies and studies not funded by industry are

did not show a significant association.

Collagen is a structural protein that helps keep skin firm and elastic.

Starting in our 20s, our body's production of collagen starts to decline, which is why people turn to collagen supplements.

When it comes to skin, randomized control trials have found that taking it for eight to 12 weeks can indeed improve things like depth of wrinkles, skin elasticity, and dermal thickness.

But a recent meta-analysis of such studies came with a big caveat, says dermatologist Marianne Macrita Sena of Harvard.

Sena says if you want to boost your skin, focus on things that are backed by strong science, like using sunscreen during the day and retinol at night.

Maria Godoy, NPR News.