Formerly known as Formula 15, Perricone MD High Potency Classics: Face Firming Serum is a powerhouse treatment that includes the highest potency of Perricone MD’s signature sciences. This intense serum visibly smoothes skin & reduces the length, width & depth of wrinkles while improving firmness. So potent you may feel a slight tingling after application.Same product, new look! Perricone MD High Potency Classics Face Firming Serum.