Summary Acne is one of the most common skin diseases that leads to persistent stigmatization and negatively affects the quality of life of patients. Currently, there are many treatments for this disease, but isotretinoin is the most effective against severe forms of acne and those cases where other forms of therapy have failed. Isotretinoin is an oral retinoid that has been used in clinical practice for about 40 years. This drug affects all the key links in the pathogenesis of acne, which determines its high effectiveness. Many clinical studies have been devoted to the study of the mechanisms of action of this drug, the specifics of its purpose, and undesirable side effects. Nevertheless, today, both patients and doctors have a number of misconceptions about the use of isotretinoin, which raises concerns about its administration, errors in treatment tactics, and low adherence to treatment. This article discusses the main issues about the mechanisms of action of isotretinoin, the specifics of its administration, indications and contraindications for use, undesirable side effects and ways to correct them, as well as the contradictions in the tactics of prescribing this drug that prevent its effective use. Special attention is paid to choosing the optimal therapeutic dose of isotretinoin and the duration of the course of treatment. In addition, the article discusses the main factors leading to failures in systemic retinoid therapy: slowing the onset of clinical response, the development of relapses after treatment, among which are the features of the course of the disease, the patient's age, his hormonal background, as well as the specifics of the dosage of the drug and the duration of its administration.