Generic levonorgestrel tablets, known as i-pill, are a progestin-only emergency contraceptive used to prevent pregnancy after unprotected intercourse or contraceptive failure, effective within 72 hours. The active ingredient, levonorgestrel, is available under various brand names, and common side effects include nausea, abdominal pain, and menstrual changes. Contraindications include hypersensitivity to levonorgestrel, current pregnancy, and certain medical conditions, and it is advised to take i-pill as soon as possible for maximum effectiveness.