Brand from Canada: The Ordinary. PHA 5% Exfoliating Lip Serum is a gentle chemical-based exfoliator for lips with 5% gluconolactone and 1.5% alpha hydroxy acids to smooth and hydrate lips. Gluconolactone is a polyhydroxy acid (PHA) that works to dissolve the structures that hold dead skin cells together. Due to their larger molecular weight, PHAs work on the surface of the skin to offer mild exfoliation, making them suitable for sensitive skin.This formulation also includes a high concentration (>50%) of glycerin to improve hydration and retain moisture as well as ectoin to support the skin barrier and offer long-term hydration. It also contains a black carrot extract which is known for its antioxidant properties and provides a mild pink colour to the formulation. This plant-derived ingredient may contribute to colour variations in the product ranging from vivid pink to pale peach however should not impact efficacy.PHA 5% Exfoliating Lip Serum helps to promote skin renewal on the lips to improve th