When people get injections of hyaluronic acid, almost everyone is happy with the results, and most side effects are just mild bruising, swelling, or soreness that goes away in two weeks.

If you get a hyaluronic acid injection alone, your skin might look better than if you get the same injection mixed with other ingredients—based on studies that looked at 8 groups with just hyaluronic acid and 5 groups with mixtures.

Getting hyaluronic acid injections in your face might make your skin look and feel more hydrated, firmer, smoother, and less tired-looking, according to some small studies in adults between 25 and 75.

When you inject hyaluronic acid just under the skin, it makes your skin feel more hydrated, bouncier, and smoother—and scientists use this as a gold standard to see if taking hyaluronic acid pills does anything similar.

There isn't strong proof that injectable hyaluronic acid makes your face skin better—most of the studies done so far are small, not fair tests, and might be skewed, so we can't be sure it actually causes the improvement.