Fumaric acid ek natural dicarboxylic acid hai jo skincare mein pH balance karne aur acidify karne ke liye use hota hai. Kabhi kabhi iska fumaric acid thoda sa exfoliating effect bhi de sakta hai. Iska esters (fumarates) system ke andar more commonly use hote hain. Skincare products mein typically pH adjuster ke taur par add hota hai jisse formula ka pH theek rahe.