This is an azelaic acid serum focusing on gentle acne treatment and mark fading. It adopts an appropriate concentration of azelaic acid formula, balancing acne efficacy and skin tolerance, suitable for various problem skin types such as oily acne-prone, sensitive acne-prone and rosacea skin. Azelaic acid inhibits Cutibacterium acnes, improves inflamed acne and closed comedones, regulates keratin metabolism and unclogs pores. It also inhibits tyrosinase activity, fades red acne marks and pigmented acne marks, evens skin tone and improves post-acne dullness. The formula is compounded with centella asiatica extract, panthenol and sodium hyaluronate soothing moisturizing ingredients to reduce acid irritation, relieve acne redness discomfort, hydrate and repair, and prevent dry peeling. Alcohol-free, fragrance-free and free of irritating preservatives, the formula is gentle and non-tightening, and does not damage the skin barrier. It has a fresh gel serum texture, absorbs quickly and is non-sticky, non-comedogenic and non-pilling. It is recommended to dab or apply a thin layer locally on acne and acne mark areas. Start with 2-3 times a week to gradually build tolerance, then adjust frequency. Daily sunscreen is required during use. Long-term use reduces recurring acne, fades acne marks, and improves rough texture and redness.