La Roche-Posay Effaclar Duo+M Patch x22 offers a localized solution that visibly reduces acne blemishes in as little as 3 hours, from the first signs of a blemish through to more persistent imperfections. Powered by hydrocolloid technology, these patches work in different ways. First, they form a protective barrier that adheres firmly to the skin, shielding blemishes from external contact, bacteria, and the risk of manual manipulation, all of which can worsen inflammation and increase the likelihood of scarring.