When rats and dogs swallow a big molecule called hyaluronan, their bodies absorb it and it shows up in places like their joints, spine, and saliva glands—and it stays there for almost two days.

When mice swallow hyaluronan, only about 1 in 500 parts of it actually gets into their body without breaking apart—so most of it just passes through without being absorbed.

When rats and dogs swallow a special kind of slippery molecule labeled with a tracking dye, the dye shows up in their skin, bones, and joints a day later—but a different tracking dye (technetium) doesn’t show up anywhere.

When rats swallow a special kind of big molecule labeled with a traceable marker, most of it comes out in their poop within two days — like 9 out of 10 pieces or more.

When mice swallow hyaluronan, almost none of it gets into their bloodstream whole—just a tiny bit—so any effects they feel probably come from gut bacteria breaking it down, not from the original substance.

Taking hyaluronan by mouth might help your skin stay hydrated for up to two weeks after you stop taking it, maybe because it slows down how fast your skin sheds its outer layer and keeps your skin cells active longer.