Achieving fuller lips doesn’t require a trip to the dermatologist’s office (unless you want it to, of course). There’s a simple ingredient that can give your lips a modest plumping effect: hyaluronic acid.

Hyaluronic acid is a humectant, which means it’s a molecule that attracts and binds to water, says Blair Murphy-Rose, MD, FAAD, a board-certified dermatologist based in California and the founder of Skincare Junkie.

“It can hold up to a thousand times its weight in water,” helping the skin retain moisture and prevent the water from evaporating, adds Pooja Rambhia, MD, a board-certified dermatologist at Union Derm in New York City. “[Hyaluronic acid] can significantly increase skin hydration, it can improve skin elasticity, texture, and also the appearance of fine lines and wrinkles.”

Does hyaluronic acid really plump the lips?

Applying a topical hyaluronic acid serum like the ones you’d typically use in your skincare routine can plump your lips. Dr. Rambhia explains that there’s some clinical evidence that applying topical hyaluronic acid can “draw some water to the lip surface and into the superficial tissue, and create this temporary volumizing effect by way of hydration.”

Both she and Dr. Murphy-Rose emphasize that the effects are subtle and will never be as dramatic as a lip filler. “It will kind of hide the fine lines and wrinkles and just give more of a hydrated look rather than true volume increase,” Dr. Murphy-Rose adds.

How does hyaluronic acid differ from traditional lip plumping glosses?

A lot of lip plumping glosses have ingredients like Schezwan pepper, cinnamon, or peppermint, which cause vasodilation, or the widening of the blood vessels, Dr. Rambhia and Dr. Murphy-Rose explain.

This increases blood flow to the tissue, “and by virtue of that, you get swelling, and there’s your plumping effect,” Dr. Rambhia says. “Oftentimes, this is accompanied by a tingling, burning sensation, which for patients who have more sensitive lips can cause a contact dermatitis type of reaction.” However, these spicy ingredients may create a more visible plumping effect than hyaluronic acid alone.

How can I lock in the moisture after applying hyaluronic acid?

Using an occlusive product, like Vaseline or Aquaphor, in addition to applying hyaluronic acid helps retain moisture. “You’re getting less transepidermal water loss, so it’s going to keep the moisture in there for longer,” Dr. Murphy-Rose explains.

Is there anyone who shouldn’t use hyaluronic acid?

Hyaluronic acid is a gentle, very well-tolerated, safe ingredient for sensitive skin, Dr. Murphy-Rose says.

What you will want to look out for, though, is if the hyaluronic acid serum has other fragrances or preservatives, which could cause reactions, Dr. Rambhia notes. “But barring those types of contact reactions…you can’t really overdo it.”

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