Hyaluronic acid, an active ingredient that slows down skin ageing?

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 hydrating role and its ability to retain up to 1,000 times its own weight in water. Beyond this function, it contributes to the architecture of the skin. By filling the spaces between collagen and elastin fibres, it ensures tissue cohesion and maintains the volume of the skin. Hyaluronic acid is what gives the face its plump appearance, its suppleness, and its ability to show lines and wrinkles less quickly under the effect of facial expressions.

However, the body’s hyaluronic acid reserves 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 exacerbated by external aggressions such as UV radiation, pollution and tobacco. It is estimated that by the age of 50, the natural reserve of hyaluronic acid has decreased by half. This depletion leads to disorganisation of the dermis: the skin loses its internal support, the cutaneous tissue sags and slackening develops. This deficit in water content and structure creates ideal conditions for the appearance of the first fine lines, which gradually evolve into wrinkles that are deeper.

A must-have in 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 immediately 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 efficacy of a hyaluronic acid serum (with unspecified concentration) was particularly highlighted in a study conducted on 40 women showing signs of photoageing. After six weeks of twice-daily application, corneometry measurements revealed an increase in skin hydration of an average of 55%. Clinically, the investigator observed that the skin was significantly smoother and plumper, and that superficial wrinkles and dehydration fine lines were reduced.

These results, supported by 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. This study compared the effectiveness of a cream containing hyaluronic acid alone with that of a formulation combining hyaluronic acid and 1% vitamin C. Although both groups showed significant improvements in elasticity and wrinkle reduction, the addition of vitamin C further amplified the benefits in terms of complexion uniformity. Indeed, the group using the combination observed a 45% reduction in hyperpigmentation, compared with 31% for hyaluronic acid alone.

Hyaluronic acid applied topically therefore helps to combat the signs of skin ageing, even more so when it is combined with an antioxidant active ingredient such as vitamin C.

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

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

However, this solution has certain limitations. The hyaluronic acid being a resorbable molecule, the effects are not permanent: depending on the area treated and the density of the product, the results generally last between 6 and 18 months. Furthermore, the procedure must absolutely be carried out by a qualified healthcare professional in order to minimise the risk of side effects, such as oedema, 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 remains a medical procedure that requires a prior consultation to assess the benefit–risk balance.

While the use of creams and injections are well-established methods, the ingestion of hyaluronic acid to mitigate skin ageing remains a matter 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 could potentially benefit from this distribution of hyaluronic acid to improve its hydration and structure, but this is not guaranteed, even though some studies suggest that dietary supplements containing hyaluronic acid may be of interest.

A double-blind, placebo-controlled study conducted over 12 weeks on 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 treatment. Despite these encouraging findings and the absence of reported side effects, the authors emphasise the need for studies on larger samples to confirm these effects over the long term.

While supplementation with hyaluronic acid appears to be a useful adjunct for targeting skin ageing, we recommend seeking the advice of 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).