Propylene Glycol

Irritancy: 0-0Comedogenicity: 0-0Humectant

The details

Propylene Glycol is a synthetic, colorless, odorless liquid that has been a staple in cosmetics for decades. It is a skin conditioning agent, humectant, and solvent. As a humectant, it draw water to the skin to reduce flaking and restore suppleness. It's also a solvent that helps dissolve other actives and keeps formulas stable across temperature changes. The CIR Expert Panel has confirmed this ingredient to be nontoxic and clinical studies show no sensitization at cosmetic use concentrations. True allergic reactions are quite rare: a 15-year retrospective study of 6,751 patients found only 0.31% had a positive reaction (and less than half were considered clinically relevant). It seemed that when sensitization does occur, it's most commonly linked to topical medication (like corticosteroids) and not cosmetics. Allergic contact dermatitis also appears largely limited to individuals with underlying skin conditions. Overall, propylene glycol is a well-studied ingredient that most people can tolerate without issue.