NIB True Botanicals Phyto-Retinol Sleep Serum Retail: $90 Size: 1oz | 30mL A Smarter Way To Retinol. Phyto-Retinol Sleep Serum is powered by Peptilium, clinically proven to work 2X faster and better than traditional retinol without the sensitizing side effects. Our new Phyto-Retinol Sleep Serum is the world’s first skincare product to be formulated with Peptilium®, a breakthrough ingredient that is clinically proven to work 2X faster and better than traditional retinol. While traditional retinol is known to disrupt the skin barrier - which is what leads to redness and dryness - Peptillium® delivers all those dramatic anti-aging results without the sensitizing side effects. Phyto-Retinol Sleep Serum: A smarter way to retinol.