"Lea" most commonly refers to Lauramide DEA (Lauric Diethanolamide) or to Linoleamide-type ingredients used as foam boosters, thickeners, and emollients in cleansers and other rinse-off formulations. It is a formulation/base ingredient rather than a treatment active.
| Reported effect | How often | Notes |
|---|---|---|
| Skin irritation | Uncommon | Mild irritation or stinging possible, mainly in leave-on or high-concentration use. |
| Allergic contact dermatitis | Rare | Sensitization reported in some patch-test studies, particularly to diethanolamide derivatives. |
| Nitrosamine contamination concern | Rare | Diethanolamide ingredients can form potentially harmful nitrosamines if combined with nitrosating agents; a formulation-quality issue rather than direct topical effect. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.