A Stable Emulsion of Retinol This water-free formulation contains 1% pure Retinol, an ingredient that can reduce the appearances of fine lines, of photo damage and of general skin ageing. While Retinol has been studied extensively, it is irritating to the skin and newer technologies exist that mimic the visible effects of Retinol without causing skin irritation. For this reason, we generally recommend using Advanced Retinoid 2% instead of this formulation. Note: This formulation can be diluted to reduce irritation potential while skin builds tolerance. Directions: Apply a small amount to face in the PM as part of your skincare regimen. Do not use with other retinoid treatments. Use sun protection in the AM.