For your skin
Replenishes one of the actual humectant molecules your own skin makes. Levels drop in eczema and with age, so topping it up genuinely helps dry, dehydrated, or atopic-prone skin feel less tight.
Want the science? Keep reading ↓Mechanism of action
Sodium salt of pyrrolidone carboxylic acid — a natural moisturizing factor component produced by filaggrin breakdown; binds water in the upper epidermis and is measurably depleted in atopic and aged skin.
Why we tier this moderate
4 cited papers across 3 countries. The mechanism is well-described and there's at least one controlled trial in the literature, but we tier this Moderate rather than Strong to stay honest about how many specific papers we cite directly.
Cited research
Novel design of pyrrolidonecarboxylic acid and sodium dilauramidoglutamide lysine complex for targeted drug delivery to human stratum corneum, International Journal of Pharmaceutics 2025
Baldwin H, Del Rosso J, Going Beyond Ceramides in Moisturizers: The Role of Natural Moisturizing Factors, Journal of Drugs in Dermatology 2024 — review establishing PCA (pyrrolidone carboxylic acid) as a core skin natural moisturizing factor alongside amino acids, urea, lactate, and electrolytes; essential to barrier function and xerosis treatment
Li L et al., Association Between Skin Acid Mantle, Natural Moisturizing Factors, and Antibacterial Activity Against S. aureus in the Stratum Corneum, Clinical Cosmetic and Investigational Dermatology 2023 — PCA and urocanic acid as NMF components contribute to skin antibacterial defense; 1-unit pH drop = 68.1% S. aureus cell death
Nakagawa N et al., Decreased lactate and potassium levels in natural moisturizing factor from the stratum corneum of mild atopic dermatitis patients are involved with the reduced hydration state, Journal of Dermatological Science 2012;66(2):136-43
Sources: PubMed · KCI · J-Stage · CNKI · Wanfang · SFD · MFDS · Cochrane · SCCS · CIR. Every entry points to a specific document. See methodology for what each outcome label means.