1,2-Propanediol (propylene glycol) is a small diol used in skincare as a humectant, solvent, and penetration enhancer that helps dissolve actives and retain moisture. It is widely used as a base/formulation ingredient rather than a treatment active.
| Reported effect | How often | Notes |
|---|---|---|
Mild transient stinging or irritation | Uncommon | More likely on compromised or sensitive skin and at higher concentrations. |
Allergic contact dermatitis | Uncommon | Recognized contact allergen; confirmed via patch testing in sensitized individuals. |
Irritant contact dermatitis | Rare | Typically associated with high concentrations or occlusion. |
Skin dryness with prolonged high-concentration exposure | Rare | Paradoxical drying reported at elevated levels in some individuals. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.