Review (5/5): Great OTC option
Azelaic acid is a decent option for acne and hyperpigmentation, which is why I buy this. This is a lower percentage than the prescription formulations (which I believe run 15% or higher) but they are also about 5x cheaper (if insurance does not cover the prescription version). Also, I've heard this is less irritating to skin than the higher percentages from others who have tried both. I hope The Ordinary keeps making this without jacking up the price.
P.S. I usually don't write reviews unless I'm procrastinating, have strong feelings one way or another about a product, or when I remember that I rely on good reviews from real people to make purchase decisions (I always check amazon profiles of informative reviews to be sure it's not a one off bot / paid review).