The science
The cleanser's evidence rests on the three acids it combines and on the format that limits them. Gluconolactone, the lead exfoliant, is the best-studied polyhydroxy acid: a 2021 study in Skin Research and Technology used corneometry to show increased skin hydration after application of 10 and 30 percent gluconolactone, and a 2023 study in the Journal of Cosmetic Dermatology found that gluconolactone peels at the same strengths reduced sebum and transepidermal water loss without the irritation profile of glycolic acid; both used leave-on concentrations far above what a daily cleanser would carry, so the relevant conclusions are about the ingredient's mildness and humectancy rather than its effect at this dose. Salicylic acid's record as a keratolytic and comedolytic is long, and the 2020 Cochrane review of topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acids for acne found evidence for salicylic acid and for alpha-hydroxy acids in mild acne, though at leave-on treatment concentrations and with low-certainty evidence overall; the undisclosed level in this rinse-off is below the OTC acne threshold and the product makes no acne claim. Mandelic acid's appeal is its large molecule and slow penetration, which give it the gentlest profile among alpha-hydroxy acids and make it a common choice for darker and reactive skin, though the clinical literature specific to mandelic acid remains thin and mostly concerns peels. The format matters as much as the actives: a cleanser is on the skin for under a minute, so its acids act on the outermost corneocytes and pore openings only, which is the mechanistic reason the product is both gentle and limited, and the surfactant base follows the mildness hierarchy set out in the 2004 Dermatologic Therapy review on cleansing without compromise, using amphoteric and glucoside surfactants that bind least to skin protein and lipid. Niacinamide and panthenol are well-supported soothing agents in leave-on products; in a rinse-off their contribution is a modest offset to the acids during the wash. No study of this specific cleanser has been published, and its concentrations are not disclosed.
References 4 ShowHide
- Corneometric evaluation of skin moisture after application of 10% and 30% gluconolactone — Skin Research and Technology (2021)
- Evaluation of the effects of 10% and 30% gluconolactone chemical peel on sebum, pH, and TEWL — Journal of Cosmetic Dermatology (2023)
- Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha-hydroxy acid) for acne — Cochrane Database of Systematic Reviews (2020)
- Cleansing without compromise: the impact of cleansers on the skin barrier and the technology of mild cleansing — Dermatologic Therapy (2004)