Dr. Dennis Gross Skincare Vitamin C Lactic 15% Vitamin C Firm & Bright Serum in Beauty: NA. Dr. Dennis Gross Skincare Vitamin C Lactic 15% Vitamin C Firm & Bright Serum in Beauty: NA. This antioxidant-rich serum with powerful 15 percent L-ascorbic acid plus lactic acid visibly improves signs of aging. Vitamin C is an essential vitamin that helps visibly improve skin density and is associated with healthy collagen levels. Lactic acid serves as a powerful delivery vehicle for other ingredients, as it increases their penetration into the skin, and thus their efficacy.. Suitable for all skin types. Vegan and cruelty free. Targets concerns of dark spots, fine lines, wrinkles, firmness and elasticity. 30mL/1 oz. Once daily, apply four to six drops all over clean, dry skin.. This serum may cause a slight tingling sensation until skin is acclimated.. For optimal results, apply after the Dr. Dennis Gross Skincare® peel (sold separately).. DDEN-WU39. BA588610.