Salicylic acid

Yes. Salicylic acid is the main beta hydroxy acid used in skincare. Unlike glycolic or lactic acid, which are water-soluble AHAs, it dissolves in oil, so it can work inside pores as well as on the surface. That's why it's the go-to exfoliant for blackheads and oily, breakout-prone skin.

No, but they're related. Aspirin is acetylsalicylic acid, a different compound that your body can convert to salicylic acid. Putting salicylic acid on your face doesn't act like swallowing an aspirin, but people with a salicylate or aspirin allergy should check with a doctor or pharmacist before using it.

Often, but carefully. Both can irritate, and using them together raises the odds of dryness, peeling and stinging. The cautious route is alternating nights, or salicylic acid in the morning and retinol at night, and adding one at a time. If your skin burns or flakes, cut back before you add anything else.

Evidence is limited and advice varies. Low-strength topical products used on small areas are generally treated differently than oral salicylates or large-area, high-strength use. Because the answer depends on the concentration and how much you apply, ask your OB or dermatologist before keeping it in your routine.

Plan on weeks, not days. Oil and blackheads may look better sooner, but breakouts typically need a month or two of consistent use to judge. Warts are slower still, often taking several weeks of daily treatment. If nothing changes after about two months, the problem may be strength, product type, or the wrong diagnosis.