Hyaluronic acid is in everything cosmetic, but is it all that?

Take a close look at cosmetics stores and drugstore beauty sections and you’ll notice an ingredient dominating the shelves. Yes, hyaluronic acid.

Just as argan oil once had its moment, the spotlight is now on the substance. In addition to face creams, it is found in shampoos, micellar water (used to cleanse the skin), lipsticks and glosses, all of which claim to be hydrating. For many, the promise is fulfilled and felt on the skin. There are dermatologists, however, who see exaggerations.

Produced naturally in our body, hyaluronic acid has the function of making the skin firmer. “One of the layers of our skin, the dermis, is composed of hyaluronic acid. It is a molecule with a support function, as if it were a gelatin that leaves the skin firm, a sponge that concentrates the water in that place”, says dermatologist Felipe brook. According to him, as the ingredient is cheap to produce, it has become a darling of cosmetics when the objective is to moisturize.

The L’Oréal Group, which encompasses 21 brands in Brazil (including Vichy, La Roche Posay, Skinceuticals, Cerave and Garnier), invests in many products with hyaluronic acid and sees room to further grow its portfolio.

“It is a substance with many possibilities and that makes sense for both skincare and [cuidados com a pele] how much for haircare [cuidados com o cabelo]. As it has strong dermatological action assets, and is even widely used in clinics, it manages to deliver results even in a minimalist routine”, says Nathaly Martos, coordinator of scientific hair valuation at L’Oréal.

When it comes to hyaluronic acid, size matters. The high molecular weight is what we have from the factory (and it starts to decrease after the age of 25), but the problem is that, precisely because of its size, it doesn’t penetrate the skin.

“What goes into the skin is low-molecular-weight hyaluronic acid, but there are no published studies showing that this type of acid that you put in a cream is going to stay on the skin or it will stimulate the skin to produce more hyaluronic acid because it is degraded. in about 24 hours. But, as it is a wetting agent, it attracts water to it, and that’s why it’s interesting”, says Ribeiro, who evaluates studies in the area of ​​dermatology for the Cochrane Network.​

The doctor Alessandra Romiti, advisor to the Cosmiatry department of the Brazilian Society of Dermatology, also emphasizes the importance of the molecular weight of hyaluronic acid.

“Its size determines whether it will be used topically, in cosmetics, or injected for filling. Many cosmetic products even combine different sizes of hyaluronic acid, and companies inform doctors about this information. Therefore, a dermatologist is the best person to indicate the best type of acid and product for each person.”

Ribeiro says, however, that hyaluronic acid has contraindications, such as its use after cosmetic procedures and in very dry areas.

“It attracts water to it, so it ends up ‘stealing’ water from the dermis. It is a product that becomes more interesting if used with another occlusive substance, that is, that does not let the water evaporate”, he says. Examples of occlusive agents are glycerin, lanolin, vegetable and synthetic waxes, petroleum jelly and silicones.

American dermatologist Shereene Idriss, clinical instructor of dermatology students at the Icahn School of Medicine at Mount Sinai (United States), and who is successful on social media by dissecting skin products and treatments, also has reservations about hyaluronic acid. Her experience involved applying a lip balm with the substance and feeling her lips get even drier.

“Because high-weight acid can’t be absorbed, the industry has created the low-weight, but it doesn’t get close to the dermis where hyaluronic acid naturally is. And it still gets water from the nearest source, causing dehydration over time.” she said in a video on the subject.

Daniella Silva, coordinator and researcher of Skincare at L’Oréal, says that there are several research methods to evaluate the action of cosmetics.

“We were able to measure with a device how much the acid penetrates the skin. Then there is also the clinical research with independent institutes, in which it is possible to clinically test the effectiveness of the products. As a group, we will never use a ‘claim’ [alegação] of the product if not proven. We make sure that before we launch a product, we will have safety and efficacy data after doing a lot of testing.”