Isotretinoin is usually divided into two types: capsules, which need to be taken under a doctor’s supervision and according to your body weight, and gels, which need to be applied topically to the affected area every day before bedtime. Isotretinoin is the first-line treatment of choice for moderate to severe acne. The capsules need to be used under the supervision of a medical professional, and the dose is assigned according to the patient’s specific body weight, and is usually taken two to three times daily for two to four weeks and then adjusted as appropriate based on clinical results. In contrast, gels are usually applied externally to the affected area in small amounts at bedtime, usually over a course of 6 to 8 weeks. In addition, isotretinoin may cause transient elevation of blood lipids, and a small number of patients may also experience symptoms of liver damage while taking the drug. In addition, since isotretinoin may cause severe birth defects, patients who have a recent need for childbearing should avoid taking isotretinoin. To summarize, this drug has significant adverse reactions after taking it, so the drug must be used properly under the guidance of a professional doctor.