Octadecane is a saturated straight-chain alkane (C18H38) used in cosmetic formulations primarily as an emollient, solvent, and viscosity/texture modifier. It helps soften skin and stabilize the oil phase of creams and lotions.
| Reported effect | How often | Notes |
|---|---|---|
| Mild skin irritation | Rare | Occasional reports of transient redness or stinging, generally in sensitive individuals. |
| Contact dermatitis | Very rare | Allergic or irritant dermatitis is uncommon as hydrocarbons are largely inert. |
| Comedogenicity/pore occlusion | Rare | Heavy occlusive feel may contribute to clogged pores in acne-prone skin. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.