Can I use topical retinoic acid to eliminate acne? How does this medicine work? Topical retinoic acid can be used to treat acne. It is generally more effective for open acne and less effective for closed acne. This medication works by dissolving the keratin plugs, improving the keratinization of the follicle opening, and allowing the sebum to drain out smoothly. However, this medicine has a certain degree of irritation, and some people tend to peel and redden their skin after using it, so use it only on pimples, and choose a concentration of 0.025%. Do not choose 0.1%, this is the treatment of psoriasis, peeling serious.