Biotherm Blue Retinol Serum Night - 30 mlBiotherm Blue Retinol Serum Night 30 ml The blue retinol serum for the night regenerates the skin deeply and improves the skin quality visibly and noticeably. The night serum from Biotherm is a highly effective bioscience care innovation, which combines the highest skin renewal rate with a 100% vegan formula. The retinol serum softens wrinkles every night, improves the evenness and quality of the skin and thus ensures healthy and youthful skin every