One of our products smells like rotten eggs?! It's actually because of an ingredient called Glutathione, which naturally contains Sulfur. But don't let the smell fool you this ingredient will make 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 Does Glutathione Smell Bad What is the Smell of Glutathione and Why It Matters for Your Health Cymbiotika CYMBIOTIKA