What is Hydroxypinacolone Retinoate and what is its purpose?

Developed in the early 2000s, hydroxypinacolone retinoate, also known as HPR, is a synthetic ester of all-trans retinoic acid (vitamin A), with the chemical formula C₂₆H₃₈O₃ and a molecular weight of 398.58 g/mol. This innovative molecule was developed in the cosmetic field to provide benefits similar to retinoic acid, a retinoid used exclusively in the medical sphere and available by prescription only.

Chemically, hydroxypinacolone retinoate is more stable than retinol, a well-known derivative of vitamin A, due to the presence of the ester group in its structure. This group acts as a protective barrier around the retinoid core, limiting oxidation reactions that often affect retinol. Hydroxypinacolone retinoate is thus less sensitive to air, light, and heat. Moreover, unlike retinol, which must undergo a double enzymatic conversion (into retinal, then into retinoic acid), HPR is active upon application.

Its direct affinity for RAR (Retinoic Acid Receptors) enables the activation of signalling pathways involved in cell renewal, collagen synthesis, and pigmentation regulation, while avoiding the inflammatory cascade that often accompanies free retinoic acid. Moreover, its esterified structure slightly slows its skin penetration, contributing to a gradual release and reducing the risk of irritation. This gentle action makes it a particularly interesting choice for sensitive, reactive or beginner retinoid users.

Hydroxypinacolone retinoate stands out due to its diverse effects on the skin, far beyond simple cell renewal regulation. Its action on irregular pigmentation is particularly noteworthy: according to some sources, it may help to normalise melanin distribution and improve barrier function impaired by dryness. Thus, hydroxypinacolone retinoate could contribute to a more even and luminous complexion. Another interesting fact: hydroxypinacolone retinoate is believed to be capable of limiting inflammation and reducing redness and blemishes. This effect would be enhanced when combined with retinol and papain glycospheres, which facilitate penetration while preserving barrier function.

Furthermore, several studies in vitro and clinical trials have evaluated the effectiveness of hydroxypinacolone retinoate. A human fibroblast cellular model (HFF-1) was specifically used to compare the effects of HPR and retinyl propionate (RP), another vitamin A ester. The study revealed that a 5:9 ratio (HPR:RP) was optimal for stimulating fibroblast proliferation, increasing collagen production, and improving the expression of genes related to retinoid receptors. By subjecting 33 volunteers to patch tests, researchers also demonstrated that this combination was better tolerated than retinol, as shown in the graph below.

Finally, a clinical trial was conducted with 42 women who applied a serum containing this combination for eight weeks. The observed effects were significant: a reduction in wrinkles by 8.3%, an improvement in skin smoothness by 11.9%, a decrease in transepidermal water loss by 25.7%, and a 14.5% improvement in skin elasticity. However, these positive results were obtained through visual evaluation by a dermatologist, not through concrete measurements, which somewhat limits the conclusions. Notably, these benefits were achieved without the irritating effects often associated with pure retinol, making it a promising solution for sensitive skin or those new to retinoids.

Another comparative study examined the effectiveness of 0.1% hydroxypinacolone retinoate combined with peptides, compared to a treatment with CO₂ fractional laser - a benchmark in the management of photoaging. Conducted among 71 women aged between 40 and 65, it highlighted good clinical results, with improvements of 20 to 30% for several parameters: overall wrinkles, nasolabial folds, skin texture and softness, hyperpigmentation and lifting effect. The average difference was statistically significant for each of these criteria (p < 0.05), showing comparable effectiveness, or even superior for some parameters, to that of the laser, but with better tolerance and without invasive procedure.

Hydroxypinacolone retinoate is a next-generation retinoid capable of smoothing wrinkles, enhancing skin texture, elasticity, and uniformity while remaining well-tolerated. It thus provides a strategic alternative to retinoids, particularly for individuals with sensitive skin.

• FABBROCIN G. & al. Efficacy and safety of a new topical gel formulation containing retinol encapsulated in glycospheres and hydroxypinacolone retinoate, an antimicrobial peptide, salicylic acid, glycolic acid, and niacinamide for the treatment of mild acne: Preliminary results of a 2-month prospective study. Giornale Italiano di Dermatologia e Venereologia: Organo Ufficiale, Societa Italiana di Dermatologia e Sifilografia (2020).

• YE R. & al. The synergistic effect of retinyl propionate and hydroxypinacolone retinoate on skin aging. Journal of Cosmetic Dermatology (2023).

• YE R. & al. High stability and low irritation of retinol propionate and hydroxypinacolone retinoate supramolecular nanoparticles with effective anti-wrinkle efficacy. Pharmaceutics (2023).

• BIAN Q. & al. A functional skincare formulation mixed with retinyl propionate, hydroxypinacolone retinoate, and vitamin C on antiaging and whitening Han women in Shanghai, China. Journal of Cosmetic Dermatology (2025).

• SALIOU C. & al. Efficacy of topical hydroxypinacolone retinoate‐peptide product versus fractional CO2 laser in facial aging. Journal of Cosmetic Dermatology (2025).