Hyaluronic acid, an active ingredient that slows skin aging?

Hyaluronic acid is naturally present in the human body. It is one of the major components of the extracellular matrix of the dermis. Hyaluronic acid is best known for its moisturizing role and its ability to retain up to 1,000 times its weight in water. Beyond this function, it contributes to the architecture of the skin. By filling the spaces between collagen and elastin fibers, it ensures tissue cohesion and maintains skin volume. Hyaluronic acid is what gives the face its plump appearance, its suppleness, and its ability to show fewer “lines” as a result of facial expressions.

However, the body’s reserves of hyaluronic acid are not inexhaustible and decline over time.

From the age of 25, its synthesis by fibroblasts slows down, while its degradation by the enzyme hyaluronidase accelerates, often further driven by external stresses such as UV radiation, pollution, or tobacco. It is estimated that by age 50, the body’s natural store of hyaluronic acid has decreased by half. This depletion leads to disorganization of the dermis: the skin loses its internal support, the cutaneous tissue sags, and skin laxity sets in. This deficit in both water content and structure creates ideal conditions for the appearance of the first fine lines, which gradually evolve into wrinkles that are deeper and more pronounced.

A staple of skincare routines, topical hyaluronic acid acts through different mechanisms depending on its molecular weight. When it has a high molecular weight, it remains on the surface of the epidermis, forming a non-occlusive protective film that retains water and instantly smooths fine dehydration lines. Conversely, low molecular weight hyaluronic acid penetrates more deeply into the layers of the epidermis to stimulate the skin’s own synthesis of the molecule and strengthen the skin’s structure. These various benefits of hyaluronic acid have been confirmed by numerous clinical studies.

The effectiveness of a hyaluronic acid serum (concentration not specified) was particularly highlighted in a study conducted on 40 women showing signs of photoaging. After six weeks of twice-daily application, corneometry measurements revealed an average 55% increase in skin hydration. Clinically, the investigator observed that the skin was significantly smoother and plumper, and that fine lines and superficial dehydration lines were reduced.

These results, supported by an excellent cutaneous tolerance, confirm that the topical application of hyaluronic acid helps restore facial volume and radiance.

To enhance its effects, it is also possible to combine hyaluronic acid with other active ingredients, such as vitamin C. This was notably demonstrated in a clinical trial conducted on 91 women. The study compared the effectiveness of a cream containing only hyaluronic acid with that of a formulation combining hyaluronic acid and 1% vitamin C. While both groups showed significant improvements in skin elasticity and wrinkle reduction, the addition of vitamin C further amplified the benefits for skin tone uniformity. Specifically, the group using the combination observed a 45% reduction in hyperpigmentation, compared with 31% for hyaluronic acid alone.

Topically applied hyaluronic acid therefore helps combat the signs of skin aging, and does so even more effectively when combined with an antioxidant active ingredient such as vitamin C.

For those who are seeking a more immediate correction, hyaluronic acid injections offer a more invasive, but more effective, filling alternative.

Unlike in cosmetics, hyaluronic acid is here injected directly into the dermis or hypodermis in the form of a cross-linked gel. This method makes it possible to mechanically restore lost volume in areas such as the cheekbones, temples, or nasolabial folds, while simultaneously attracting water at a deep level, which smooths the tissues from within. Hyaluronic acid injections provide a "lifting" effect without surgery.

However, this solution has certain limitations. Hyaluronic acid is a resorbable molecule, so its effects are not permanent: depending on the area treated and the density of the product, results generally last between 6 and 18 months. In addition, the procedure must be performed by a qualified healthcare professional to minimize the risk of side effects, such as swelling, bruising, or, more rarely, inflammatory reactions. Finally, certain contraindications must be observed, particularly in cases of autoimmune diseases, pregnancy, or a history of hypersensitivity.

Injection is still a medical procedure that requires a prior consultation to assess the benefit-risk balance.

While applying creams and using injections are well-established methods, ingesting hyaluronic acid to reduce skin aging remains a subject of debate. Once ingested, the molecule is broken down into smaller fragments by the gut microbiota, which are then absorbed by the body and distributed to various tissues. The skin might benefit from this distribution of hyaluronic acid by improving its hydration and structure, but this is not guaranteed, even though some studies suggest that hyaluronic acid–based dietary supplements could be of interest.

A double-blind, placebo-controlled study conducted over 12 weeks in 40 volunteers produced interesting results. Participants who ingested 120 mg of hyaluronic acid per day showed a significant improvement in their skin condition compared with the placebo group. The researchers observed a reduction in wrinkle depth, an increase in hydration of the stratum corneum, as well as an improvement in skin elasticity. It is noteworthy that these effects only became statistically significant after 8 to 12 weeks of supplementation. Despite these encouraging findings and the absence of reported side effects, the authors emphasize the need for studies on larger samples to confirm these effects over the long term.

While hyaluronic acid supplementation appears to be a useful adjunct for targeting skin aging, we recommend consulting a healthcare professional before beginning a course of treatment.

• DRAELOS Z. D. & al. Efficacy evaluation of a topical hyaluronic acid serum in facial photoaging. Dermatology and Therapy (2021).

• MASUDA Y. & al. Oral hyaluronan relieves wrinkles and improves dry skin: A 12-week double-blinded, placebo-controlled study. Nutrients (2021).

• KEROB D. & al. Benefits of topical hyaluronic acid for skin quality and signs of skin aging: From literature review to clinical evidence. Dermatologic Therapy (2022).

• TURSI F. & al. Oral intake and topical application of hyaluronic acid ameliorates skin aging signs: Efficacy results of a placebo-controlled in&out trial. Cosmetics (2025).

• YU M. & al. The effect of local hyaluronic acid injection on skin aging: A systematic review and meta-analysis. Journal of Cosmetic Dermatology (2025).

• ROSSI E. & al. Clinical and instrumental evaluation of the anti-aging effectiveness of a cream based on hyaluronic acid and a cream based on hyaluronic acid and vitamin C: A prospective, multicenter, 8-week, parallel-group randomized study on 91 subjects. Cosmetics (2025).

• MACIEJCZYK M. & al. Hyaluronic acid and skin: Its role in aging and wound-healing processes. Gels (2025).