The science
The mask's mechanism is well understood: algin, the sodium alginate of brown seaweed, forms a gel that calcium ions cross-link into a rubbery, insoluble sheet, and the calcium sulfate and tetrasodium pyrophosphate in the gel sachet control that reaction once water from the liquid sachet arrives, so the paste spreads for a minute and then sets. The set sheet is occlusive, and occlusion over twenty to thirty minutes raises stratum corneum hydration and the penetration of whatever sits beneath it, which is the basis for the softening, plumping and evenness users see on peeling; it is also the reason fragrance under such a mask carries more sensitisation risk than the same fragrance in a leave-on. Diatomaceous earth and bentonite give the paste body and absorb surface oil, and the dozen plant oils, reviewed for their emollient and barrier-lipid roles in the 2017 International Journal of Molecular Sciences survey of topical plant oils, are delivered to the skin as the sheet sets; glycerin, panthenol, sodium hyaluronate and allantoin in the liquid contribute humectant and anti-irritant effects at cosmetic levels.
The firming claim rests on hydrolysed vegetable protein, a mixture of plant peptides and amino acids that forms a hygroscopic film on the skin; the film contracts as it dries, producing a measurable but transient tightening that reverses on cleansing, and there is no evidence that topical hydrolysed proteins alter dermal elastin or collagen. The glycoproteins and the Gongjin extracts, ganoderma, angelica, cornus, asparagus, thyme and kaempferia, have laboratory data on constituents and no clinical evidence as a topical blend at these doses.
The risks are the declared fragrance allergens, citronellol, limonene, geraniol and linalool, all among the twenty-six labelled components studied in the 2017 Contact Dermatitis multicentre patch-test series, applied under an occlusive sheet, and the sweet almond and olive oils, which are minor allergen and comedogenic notes for acne-prone users. Alginate itself is inert and the peel is atraumatic, unlike polymer peel-off masks.
References 2 ShowHide
- Anti-Inflammatory and Skin Barrier Repair Effects of Topical Application of Some Plant Oils — International Journal of Molecular Sciences (2017)
- Non-mix fragrances are top sensitizers in consecutive dermatitis patients - a cross-sectional study of the 26 EU-labelled fragrance allergens — Contact Dermatitis (2017)