The science
The structure of this cream follows the well-established two-part logic of effective moisturization: humectants that bind water in the stratum corneum and an occlusive lipid film that slows its evaporation. On the humectant side, glycerin is the best-studied moisturizing ingredient in dermatology, and the formula adds sodium hyaluronate along with mannose and sodium PCA, the latter being a component of the skin's own natural moisturizing factor. The occlusive side is built from shea butter, squalane, jojoba oil and dicaprylyl ether rather than petrolatum; shea's triglyceride and unsaponifiable fraction and squalane's close resemblance to the skin's own squalene make this a breathable, skin-compatible lipid layer, and the absence of petrolatum is why the cream reads lighter than its texture. Niacinamide at a functional concentration has published evidence for increasing epidermal ceramide and free fatty acid synthesis and for reducing transepidermal water loss in dry skin, which is the mechanistic reason it belongs in a barrier cream rather than only in a brightening serum.
The franchise-specific science concerns Vichy's volcanic water minerals and the Vitreoscilla filiformis ferment. A 2022 review in the Journal of the European Academy of Dermatology and Venereology (https://pubmed.ncbi.nlm.nih.gov/34979590/) by L'Oréal and Vichy researchers summarised in vivo and ex vivo studies of the Minéral 89 serum base, a formulation of 80% Vichy volcanic mineralizing water, 5% Vitreoscilla ferment, 4% niacinamide, 0.4% hyaluronic acid and 0.2% vitamin E, reporting faster barrier recovery after tape-stripping and thermal stress, accelerated skin renewal, better microbiome recovery after a harsh cleanser, and improved clinical signs of stressed skin in Caucasian and Asian women. A companion review in the same issue (https://pubmed.ncbi.nlm.nih.gov/34979591/) described how the ferment grown in the volcanic water increased barrier proteins such as filaggrin and claudin-1 and antimicrobial peptides in keratinocyte and explant models. These studies are company-funded and tested the serum, not this cream, and in the rich cream both the ferment and the mineral fraction sit lower in the ingredient order than in the serum, so their contribution here is plausibly supportive rather than primary. The 100-hour hydration claim rests on corneometry after a single application, a legitimate instrument measure of how long the lipid film keeps water in the skin, and it should be read as evidence of occlusive durability rather than as a dosing interval.
References 2 ShowHide
- A dermocosmetic formulation containing Vichy volcanic mineralizing water, Vitreoscilla filiformis extract, niacinamide, hyaluronic acid, and vitamin E regenerates and repairs acutely stressed skin — Journal of the European Academy of Dermatology and Venereology (2022)
- A combination of Vitreoscilla filiformis extract and Vichy volcanic mineralizing water strengthens the skin defenses and skin barrier — Journal of the European Academy of Dermatology and Venereology (2022)