Gentle Glow PHA Serum

Lactobionic acid at 5%, a polyhydroxy acid. Larger molecules than glycolic or lactic, so it exfoliates more slowly.

Lactobionic acid at 5%, with gluconodeltalactone as a second polyhydroxy acid. PHAs are larger molecules than the alpha hydroxy acids, so they move into skin more slowly and exfoliate more gently. Lactobionic acid is also a humectant, which means it holds water while it works — unusual for an exfoliant.

Slow is the point of it. If you are expecting the bite of a strong glycolic, this will feel like very little is happening, and that is the design rather than a fault.

At night, after cleansing, before your night cream. Whether you need a nightly acid as well as a Vitamin A is a consultation question.

Actives: Lactobionic Acid (PHA, exfoliant) 5%

Suits: Skin new to acids, and skin that finds AHAs too much.

Not for: Skin already on a stronger acid or a nightly Vitamin A, without a plan.