What it is
Dipropylene glycol is a clear, colorless glycol liquid that works mainly as a solvent and a viscosity-decreasing ingredient, with humectant and skin-conditioning properties. In formulas it helps dissolve other ingredients, thin overly thick textures, and draw and hold moisture. It exists as a mixture of structural isomers rather than a single pure compound.
Safety & warnings
Dipropylene glycol is reported to have a favorable safety profile, with minimal toxicity and low potential for skin or mucosal irritation, which is consistent with its widespread use as a solvent and humectant in personal care products. It is a common, generally well-tolerated ingredient across many leave-on formulas.
Origin & sourcing
It is a synthetic glycol obtained from propylene oxide chemistry, generated as a byproduct during the industrial hydration of propylene oxide to make propylene glycol.
Questions everyone asks
What is dipropylene glycol used for in sunscreen?
It acts as a solvent that helps dissolve other ingredients, thins the texture, and works as a humectant to help hold moisture.
Is dipropylene glycol the same as propylene glycol?
No. It is a related but larger glycol, formed as a byproduct when propylene glycol is manufactured.
Is it irritating to skin?
It is reported to have low irritation potential and is widely used in skincare, though anyone with a known glycol sensitivity should take care.