Hydrogenated Phosphatidylcholine

Hydrogenated phosphatidylcholine is a saturated phospholipid used in low concentrations as a barrier-supporting emollient, liposome/vesicle former, and penetration/texture aid; it is generally well tolerated in sensitive-skin and ophthalmic-type formulations. Clinical and patch-test data suggest a low irritation profile, but as a lipid-derived emulsifier/vehicle it can occasionally provoke stinging or rare contact reactions in highly reactive or compromised eczema skin, especially in leave-on products combined with other actives. Given that non-zero risk exists in severely sensitized populations, it is best classified as very gentle rather than inert. Safety Notes: In mass-market leave-on serums/creams and many emulsions, hydrogenated phosphatidylcholine is often used at very low levels (~0.01–0.1%) as a lamellar emulsion/skin-conditioning lipid or to support dispersion of actives. More “barrier repair,” liposomal/lamellar-structured, and phospholipid-rich concentrates marketed to consumers commonly run ~0.5–3%, with a small number of high-phospholipid OTC booster/ampoule-type products reaching ~5% where the phospholipid system is a primary structuring/encapsulation component. It is less common in rinse-off products and, when present, is typically toward the low end due to cost and rinse-away inefficiency.