Undecane is a lightweight branched or linear hydrocarbon (C11 alkane) used in cosmetic formulations as a volatile emollient and solvent, often paired with tridecane to replace silicones and provide spreadability and a smooth skin feel. It functions as a base/carrier ingredient rather than a therapeutic active.
| Reported effect | How often | Notes |
|---|---|---|
Mild skin irritation | Rare | Occasional transient redness or stinging, typically in sensitive or compromised skin. |
Allergic contact dermatitis | Very rare | Sensitization to hydrocarbon-based emollients is uncommonly reported. |
Eye irritation | Rare | Can cause temporary stinging if formulations contact the eyes. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.