Often described as a "facial in a bottle," Biologique Recherche's is widely considered the most iconic and transformative chemical exfoliant in the skincare world. Created in the 1970s by Dr. Yvan Allouche, it is designed to recondition the epidermis over a 50-day cycle—hence the name "P50"—by balancing pH, regulating sebum, and accelerating cell turnover. Why It Is a Cult Classic Unlike standard toners that primarily refresh the skin, Lotion P50 Go to product viewer dialog for this item. is a multi-functional treatment. Lotion P50 - Biologique Recherche