Isac 20mg Capsule contains isotretinoin, a retinoid primarily indicated for the treatment of severe recalcitrant nodular acne that is unresponsive to conventional therapies such as antibiotics. Isotretinoin exerts its therapeutic effect by reducing sebaceous gland size and sebum production, normalizing follicular epithelial desquamation, and exhibiting anti-inflammatory properties, thereby addressing multiple pathogenic factors of acne. The recommended dosage of Isac 20mg Capsule varies based on patient weight and clinical response, typically initiated at 0.5 mg/kg/day and adjusted up to 1 mg/kg/day, administered orally in divided doses with meals to enhance absorption. Treatment duration generally spans 15 to 20 weeks but may be tailored according to therapeutic outcomes and tolerability. Due to its potent teratogenicity, strict adherence to pregnancy prevention protocols is mandatory for female patients of childbearing potential, including negative pregnancy tests prior to initiation and during therapy, alongside effective contraception. Common adverse effects include cheilitis, dry skin, and photosensitivity, while more serious risks involve hepatotoxicity, hyperlipidemia, and mood alterations, necessitating regular monitoring of liver function tests, lipid profiles, and psychological status. Isac 20mg Capsule should be prescribed and monitored by healthcare professionals experienced in isotretinoin therapy to ensure safe and effective use.