Hydroxypropyl Tetrahydropyrantriol Good Humectant Anti-Ageing Hydration Hydroxypropyl Tetrahydropyrantriol at a glance Derived from xylose (a sugar abundant in beech trees) Used in skin care products for its purported anti-aging and hydrating properties May help increase glycosaminoglycans within skin Also known as Pro-Xylane Hydroxypropyl Tetrahydropyrantriol description Hydroxypropyl tetrahydropyrantriol (also known as Pro-Xylane or HTP) is used in skin care products for its purported anti-aging and hydrating properties. It is a sugar-protein hybrid derived from xylose (a sugar abundant in beech trees) and is typically produced through a chemical modification process that enhances its stability. This cosmetic ingredient was developed by L’Oreal, and as such, studies related to its efficacy tend to have conflicts of interest due to their ties to L’Oreal brands. This does not mean that hydroxypropyl tetrahydropyrantriol can’t be effective for skin—it’s just something to keep in mind in terms of potential research bias. Of note, the Research Group of L’Oréal claims hydroxypropyl tetrahydropyrantriol helps support glycosaminoglycans within skin. Glycosaminoglycans are a fundamental component of skin tissue that play an integral role in skin’s natural ability to retain water (aka hydration). Another study suggests hydroxypropyl tetrahydropyrantriol is beneficial for post-menopausal skin as it improves the quantitative composition of sebum and epidermal lipids that are typically depleted during this phase of life. This study also indicates hydroxypropyl tetrahydropyrantriol may play a role in improving skin’s barrier strength. Other potential benefits of hydroxypropyl tetrahydropyrantriol as claimed by its suppliers include pro-collagen and anti-wrinkle effects when used in concentrations between 2-5%. At the time of this writing, the Cosmetic Ingredient Review Expert Panel has not analyzed this ingredient’s safety profile but there does not appear to be any concerns.