Azelaic acid is great for hyperpigmentation, post inflammatory erythema, acne and rosacea but there’s a lot of confusion about how to incorporate it into your routine. 1. First off, azelaic acid can be used morning, night, or even morning and night. And if you use a serum like the Anua 10% azelaic acid then it’s going to be one of the first steps after washing. And you can apply it first or on top of other serums like vitamin C serum- just let each absorb for about a minute between serums. One r