How Lip Filler Works 💉

Press the arrow keys to add or remove filler and watch the gel fill the spaces between lip cells.

Each pink blob represents a cell in your lip tissue, and the blue pockets are hyaluronic acid filler gel. The filler doesn't go into the cells. It sits in the tissue around them, and because hyaluronic acid holds onto water, the gel swells somewhat after injection, up to a limit set by how it's made. The added gel is what adds volume.

Lip filler adds volume at the tissue level. A provider injects a hyaluronic acid gel into the lip, and the gel itself takes up space. Hyaluronic acid holds onto water through chemical bonds, so the gel absorbs some water and swells after injection, but cross-linked filler gels can only swell to a certain level.

The cells around the filler aren't filling up with water. The extra volume comes from the gel and the water it holds.

We found no published research showing that drinking more water changes how full your filler looks.

Hyaluronic acid isn't a foreign substance. Your body makes it, about half of it is in your skin, and your body continuously breaks it down and replaces it.

Filler is cross-linked hyaluronic acid. Cross-linking makes it less susceptible to breakdown, so it lasts longer in the body than your own hyaluronic acid. Like natural hyaluronic acid, it holds onto water.

Brands make their gels differently, which changes properties such as how firm or soft the gel is. Our Juvéderm vs Restylane guide covers the lip products in more detail.

Your body eventually breaks hyaluronic acid filler down. Cross-linking slows that breakdown, which is why results last longer than your body's own hyaluronic acid but aren't permanent.