The science
The evidence for this wash is the evidence for surfactant mildness and for the limits of cleansing as oil control. On surfactants, the 2004 review in Dermatologic Therapy on cleansing without compromise established that irritation and dryness track the binding of surfactant monomers to stratum corneum protein and lipid, with ethoxylated sulfates milder than sodium lauryl sulfate and the choice of counter-ion and the addition of refatting agents further moderating the effect; the 2022 review in Molecules on soaps and syndets confirms that ranking and describes refatting esters of the kind used here as the standard way to offset lipid loss. Zinc coceth sulfate specifically has little independent literature, and the claim that its zinc counter-ion improves tolerability relative to the sodium salt comes mainly from manufacturer data, which makes it plausible rather than established. On oil control, the 2017 review of oily skin treatment options in the Journal of Clinical and Aesthetic Dermatology is clear that cleansers manage the surface appearance of sebum rather than its production, that the evidence for topical zinc's sebum-reducing effect is modest and derived from leave-on formulations, and that the interventions with real effects on production are retinoids, hormonal agents and certain procedures; a rinse-off containing zinc gluconate at sixth position should be expected to remove existing oil, not to change output. Dipotassium glycyrrhizate has anti-inflammatory activity in leave-on contexts, including the 2003 licorice gel trial in atopic dermatitis, but in a thirty-second foam its contribution is small. The 'masking fragrance' is a low-level odour neutraliser rather than a scent, but it places the product outside strict fragrance-free status. No trial of this wash on oily or acne-prone skin has been published, and the reviews describing reduced shine are consistent with what a well-formulated sulfate cleanser does on the surface.
References 4 ShowHide
- Cleansing without compromise: the impact of cleansers on the skin barrier and the technology of mild cleansing — Dermatologic Therapy (2004)
- Skin Cleansing without or with Compromise: Soaps and Syndets — Molecules (2022)
- Oily Skin: A review of Treatment Options — Journal of Clinical and Aesthetic Dermatology (2017)
- The treatment of atopic dermatitis with licorice gel — Journal of Dermatological Treatment (2003)