“Salicylic acid is considered the only BHA used in topical products,” said Dr. David Lortscher, a dermatologist and the founder and CEO of Curology. “It promotes an exfoliation, or shedding, of superficial skin cells, which provides a smoother texture and appearance to the skin.”
By actively sloughing off dead skin cells, salicylic acid prevents and treats blocked pores, and it can even give the illusion of decreased pore size.
Salicylic acid is almost always made synthetically, but it was first extracted from willow bark. You can find it in many over-the-counter products, ranging from cleansers to creams to wipes to spot treatments. It’s particularly ideal for oily and acne-prone skin types, and we recommend using it sparingly. High concentrations (at or over 2 percent) should be relegated to spot-treatment only. Milder concentrations can be used as a cleanser or cream.
Dr. Lortscher added, “BHAs do not cause photosensitivity, so they can be used morning or night, although the FDA still advises sun protection if you use a BHA product.”