Our underarm brightening serum contains glutathione, niacinamide. It can deeply moisturize the skin, provide long-lasting hydration, effectively reduce dullness, and give you a refreshing experience. Its use is simple: 1. Clean and dry armpit skin. 2. Take an appropriate amount and apply evenly to the armpits. 3. Gently massage until absorbed. And it can lighten dullness, make the armpit skin tone even, and make the skin fairer and softer.