Grace and Glow Bright & Smooth Deodorant Serum with Niacinamide and AH D Nelson Enterprises Faded gets its smell from glutathione, an ingredient thats super effective at reducing the appearance of discoloration in week Glutathione has a cysteine chain that causes it to have a sulfur like If a serum smells bad it usually means it works., This glutathione serum smells like rotten eggs and thats your first clue its highly concentrated. Glutathione is known for targeting One of our products smells like rotten eggs?! , Its actually because of an ingredient called Glutathione, which naturally contains Sulfur. , But dont let the smell fool you this ingredient will