green cream by advanced skin technology is an anti-aging retinol formulation that was developed by legendary new orleans dermatologist, dr. nia terezakis. the breakthrough delivery system used in green cream called Green Polymer Cooling Gel™, allows Green Cream® to carry one of the highest concentrations of retinol available. the patented water-based  formulation reduces irritation while improving the effectiveness of retinol.  the results are truly amazing!