As people get older, their skin naturally has a lot less of a substance called hyaluronic acid — by the time they're 75, they've got only about a quarter left compared to when they were 19.

Taking a daily supplement of sodium hyaluronate for 3 months may help keep older people’s skin thicker and more youthful by slowing down the natural thinning of skin layers and protecting the collagen that gives skin its structure.

Taking a specific type of hyaluronic acid pill every day for 3 months doesn’t make the deeper layer of your skin thicker, which means it probably only works on the top layer.

Taking a specific type of hyaluronic acid pill every day for 3 months may make the outer layer of your skin thicker, which could help your skin stay healthier and better protected.

Giving mice a specific type of hyaluronic acid pill every day for a week doesn't make more of it show up in their blood or body tissues compared to mice that just got water.