Hyaluronic Acid: The New Skincare Ingredient You Need To Know

What is hyaluronic acid?

Although hyaluronic acid (HA) has 'acid' in its name, it has none of the exfoliating properties associated with other cosmetic acids. A natural humectant, HA is the most superior skincare ingredient in terms of its ability to draw in water and hold it in the skin. "Hyaluronic acid is a naturally occurring substance in our skin – and joints – that decreases as we age," explains Dr Barbara Sturm. This accounts for the skin's tendency towards dryness as we get older.

How does it work?

HA works to retain moisture in the skin thanks to its capacity to hold water (one gram of hyaluronic acid can hold six litres of H2O). That said, there is some controversy around the actual merit HA has on skin hydration; sceptics wager that the HA molecules in skincare products are too large to penetrate the dermis, and that it needs to be injected into the skin (by mesotherapy treatments) if it is to be truly beneficial. Dr Frances Prenna Jones is an advocate of the mesotherapy option. "Some facials use ultrasound waves to help HA absorb, but the optimum penetration is directly injecting it into the dermis," she says. Those who back the skincare options agree that the newer, lower-weight HA products are the most effective. Regardless of how deep it can actually penetrate, "it is an important part of a daily beauty routine because even binding water to the surface of the skin keeps it moist and fresh," says Sturm.

Are all hyaluronic acids equal?

HA molecules alter in their molecular weight. In simple terms, low-weight (short-chain) HA is smaller, and therefore penetrates the skin to a deeper level, while the larger (long-chain) high-weight HA molecules are good for hydrating the surface of the skin. "It is essential to use topical products that contain both chains of hyaluronic acid, so that you get both benefits."

HA is also an ingredient in fillers (Restylane, for example). "It is documented that facial fillers have an actual skincare benefit, boosting the hydration of the deepest levels of the skin," explains Dr Tapan Patel.

What are the benefits?

Improving the water content in the skin strengthens its barrier, calms irritation and plumps out fine lines. "It also helps to repair inflammation, damage and environmental stress," says Sturm. "The immediate cosmetic effect is amazing too – it's wonderful under make-up." HA is non-toxic and carries no risks of irritation.

From: Harper's BAZAAR UK