Acetyl Hydroxyproline

Acetyl hydroxyproline is a modified form of hydroxyproline, an amino acid naturally present in collagen. It is created by acetylating hydroxyproline, a process that enhances its stability and skin penetration properties. In skincare formulations, it functions as a humectant, emollient and skin conditioner.The ingredient works at the cellular level to support the skin's structural integrity and barrier function, with emerging evidence suggesting it may also help mitigate certain pathways involved in skin ageing.

Acetyl hydroxyproline appears to work through multiple mechanisms. Its humectant properties allow it to bind water molecules and draw moisture into the skin, supporting hydration levels. At a deeper level, research suggests it may inhibit the glycation process—a non-enzymatic reaction between sugars and proteins that leads to collagen crosslinking and skin stiffening.The ingredient may also upregulate ceramide synthesis by influencing enzymes involved in the skin barrier's lipid production, thereby strengthening the stratum corneum and reducing transepidermal water loss.

Acetyl hydroxyproline is typically found in serums, moisturisers and specialised treatments. It can be used daily as part of a regular skincare routine. There are no known restrictions on combination with other actives, though as with any new ingredient, introducing it gradually allows you to monitor your skin's response.

Acetyl hydroxyproline is generally well-tolerated in topical skincare formulations. There are no widely reported contraindications or safety concerns for typical cosmetic use.