Increasingly present on dermocosmetics shelves, on digital channels of influencers and in offices, hyaluronic acid (HA) has become a hype among the anti-aging treatments – whether in the composition of products such as creams, masks and serums or injected as a filler directly into the skin. But will it work in any presentation? Understand the science behind the darling of the moment – and the dangers it can pose if misused.
What is hyaluronic acid?
Hyaluronic acid is a polymer naturally present in our body: it is part of the cartilage, skin, eyes and maintains the performance of the synovial fluid in the joints. It is composed of two sugars: glucuronic acid and n-acetylglucosamine. As it is negatively charged, it has the ability to bind to nearby water molecules – up to more than a thousand times its weight. It is this property of retaining moisture that makes it a powerful “rejuvenator”.
With age, the presence of hyaluronic acid decreases in the body, causing expression marks such as wrinkles – explained Gabriela Bailas, PhD in Theoretical Physics of Particles, in a video about the substance published on her channel. The loss of hyaluronic acid, collagen and elastin results in loss of tissue volume, hydration and fat, according to an article published in the blog on Health at Harvard University, in the United States.
Filling needs to be carried out by specialized professionalsSource: Freepik
Hyaluronic acid in cosmetics and offices
Due to its humectant property, hyaluronic acid has been widely used in cosmetic skin care products. According to dermatologists Kristina Liu and Janelle Nassim, authors of the article published by Harvard, to find out if these products really deliver what they promise, a detailed analysis of the type of hyaluronic acid present in the product is needed, as the substance has different molecular sizes.
“Larger HA molecules, despite being the best in binding water and hydration, cannot penetrate the skin,” explained the experts. When applied as a cream, the molecules stay on top of the skin, providing hydration only on the surface. “Smaller molecules, which bind less water, can penetrate deeper into the skin,” they said. Even so, topical use only reaches the epidermis – the most superficial layer of the skin.
“For maximum surface hydration, look for a product that contains HA molecules in a variety of sizes,” the researchers said. But Bailas drew attention to the fact that the effect of the creams is not lasting and may offer a “placebo effect”: the products do not stay on the skin, they just create a temporary film with occlusion capacity, keeping the water close while the cream is used. is present.
In the case of dermal fillers, composed of HA in the form of an injectable gel, it is possible to add volume by physically filling the area where they are placed – where they will draw water to increase the filling effect. According to Harvard researchers, they can lift the cheeks, smooth out deeper folds and creases around the mouth and chin, improve the appearance of dark circles under the eyes, moisturize and enhance the lips, and rejuvenate the hands and earlobes.
The effect is not forever: according to studies cited by Bailas in his video, the acid remains stable for approximately 12 months, ranging from 8 to 18 in total. But in order to undergo the treatment, it is necessary to observe some precautions, as the physicist warns: each location requires a different type of acid and the application must be made by a specialized professional, who understands these details. In the case of Brazil, there are four professionals authorized to apply hyaluronic acid in the office:
- Doctors – dermatologists and plastic surgeons;
- Dental surgeons.
What are the risks?
As Bailas pointed out, no cosmetic product is 100% risk-free when applied. The hyaluronic acid used in beauty and skin care products comes from the biofermentation of bacteria in the laboratory or from the comb of roosters and can cause adverse reactions such as allergy, erythema or edema and, in more severe – and rare – cases – bruises, infection, formation of nodules, hypertrophic scars and even tissue necrosis where the injection took place.
As a treatment for adverse reactions, Bailas mentioned hyaluronidase, an enzyme that dissolves the product and shows good results – but it needs to be applied within the first 24 hours after injecting the acid into the skin.
Cream or injection?
According to Harvard scholars, topical hyaluronic acid will never be as effective as an injectable filler of the substance in replacing lost volume – “even if some products are misleadingly marketed as topical fillers,” they said. But creams can be allies: “Usually are well tolerated; they often do not cause allergic reactions or irritation in sensitive skin and are safe to use on the skin during pregnancy and breastfeeding,” they said.