For an acne serum, I was surprised at how mild this formula was. My skin tolerates azelaic acid and niacinamide well, but if either of those can feel spicy on your skin, know that going in and maybe start out using it every other day and work your way up to once or twice daily, depending on your tolerance. (And if you’re wearing it during the day, don’t forget the SPF.) Since Versine’s whole thing is “gentle actives,” I wouldn’t expect a product like this one to clear up severe, allover breakouts. Personally, I tend to get hormonal breakouts concentrated on my lower jawline and chin, and for those annoying yet generally manageable flare-ups, this product has been wonderful in maintaining clear, decongested pores.