 and Jason B. from Arizona says, I never knew nitric oxide serum could solve the wrinkles that have gotten worse over the years on my forehead and around my eyes. N-101 Nitric Oxide Skin Serum improves blood flow, collagen, and hydration, leading to tighter, firmer skin. Improve the tone, texture, and clarity of your skin with N-101 Nitric Oxide Skin Serum. Order Nitric Oxide Active.