Rhaponticin, a molecule in rhubarb, activates PPARγ, a receptor that stimulates the differentiation of keratinocytes and natural hydration mechanisms.
The molecule was found to increase the production of involucrin and filaggrin to increase stratum corneum cohesion, improve barrier function and recover skin hydration. In addition, Provital says it increases the production of barrier lipids, nearly tripling ceramide levels, to protect skin from future moisture loss.
The active is recommended at 0.5–1.5 per cent in bath gels, body milks, hand creams, hair care products, shampoos, lotions, conditioners, masks, makeup and sun care products.