In general, there is no specific rule on how long it takes for acne to break out after using adapalene, and a case-by-case analysis is needed. Adapalene is a retinoid, which is mainly used in clinical practice to treat various keratotic skin diseases, such as acne and periorbital keratosis, and is one of the most routine and basic medications for the treatment of mild acne. Some patients may experience local dryness, flaking, or even redness and mild acne breakouts when they first start using it, such as within 1-3 days, and there is no specific regularity to this phenomenon. With longer use, acne symptoms will gradually reduce. If the acne breakout is more serious, it is recommended to temporarily stop the drug and go to the hospital dermatology department for timely treatment after examination by a doctor. Adapalene can be used for a long time point to point on the skin lesions, but during the use of the drug should be careful to avoid spicy and irritating food, and pregnant women, lactating women need to temporarily stop using.