What it is
Tripropylene glycol is an oligomer of propylene oxide consisting of three linked propylene glycol units. It is a water-miscible, hygroscopic liquid that helps dissolve a range of polar and semi-polar ingredients and contributes humectancy. In sunscreens and serums it can act as a carrier solvent and adjust the feel and flow of the base.
Safety & warnings
Tripropylene glycol is generally well tolerated in cosmetic use. Like other glycols it is used at modest levels, and very high concentrations could occasionally feel drying or mildly irritating on sensitive skin.
Origin & sourcing
A synthetic glycol produced from propylene oxide.
Questions everyone asks
What role does tripropylene glycol play?
It works mainly as a humectant and solvent, helping dissolve other ingredients and supporting moisture retention in the formula.
How is it different from propylene glycol?
It is a larger molecule made of three propylene glycol units, giving it lower volatility and a somewhat different solvency and feel.