Azelaic Acid

Azelaic acid is 杜鹃花酸 (dù juān huā suān) in Chinese — 杜鵑花酸 in Traditional Chinese — and also appears as 壬二酸 on labels. It's a gentle dicarboxylic acid that fights acne bacteria, calms inflammation, and fades post-acne marks.

Azelaic acid is gentler and also tackles inflammation and post-acne marks, so it suits sensitive, acne-prone skin and darker tones. Salicylic acid leans toward pore-clearing and fits oily, acne-prone skin with a fairly healthy barrier. If you flush easily or have uneven tone, start with azelaic acid.

Mild stinging and itching early on are common — an adjustment response, not an allergy. Drop to every other day or use less; it usually settles within 1–2 weeks. Only consider stopping if you get persistent redness, swelling, or a rash.

Expect 2–4 weeks for inflammation and redness to calm down, 6–12 weeks for post-acne marks to fade, and possibly longer (8–12 weeks) for rosacea. Consistency matters — don't keep switching products midway.

Yes, but both are relatively strong actives. Use them on alternate days (retinol one night, azelaic acid the next) so your skin gets recovery time. When your barrier is fragile, alternating is safer than layering them the same day.

Topical absorption is minimal, but it's best avoided during pregnancy unless your doctor explicitly clears it. Gentler options such as glycerin-based hydrators can carry you through.