I got it at my Med Spa. I already have a bottle that’s double the size so I can’t use this anytime soon Professional C® Serum 15% is formulated with 15% L-Ascorbic Acid to help brighten and even skin tone, strengthen skin's antioxidant defenses, and improve the appearance of fine lines and wrinkles. For a supercharged glow and more youthful-looking skin. Ideal for normal to combination skin types. Formulated with L-Ascorbic Acid to brighten skin Helps to neutralize free radicals For a more even-looking complexion