Methergin Injection contains Methylergometrine 0.2 mg, an ergot alkaloid used primarily for the prevention and treatment of postpartum hemorrhage due to uterine atony. It acts by stimulating uterine smooth muscle contraction, thereby reducing bleeding following delivery or abortion. This injection is indicated in obstetric practice to promote uterine tone and minimize blood loss after childbirth. Methylergometrine exerts its effect through partial agonist activity at alpha-adrenergic, dopaminergic, and serotonergic receptors, resulting in sustained uterine contractions. The onset of action is rapid when administered intramuscularly or intravenously, making it effective in acute management scenarios. Methergin Injection should be used with caution in patients with hypertension, preeclampsia, or vascular disease due to its vasoconstrictive properties. It is contraindicated in cases of hypersensitivity to ergot alkaloids, severe hypertension, and during pregnancy except during delivery. Adverse effects may include hypertension, nausea, vomiting, headache, and dizziness. Dosage and administration must be carefully followed as per clinical guidelines to avoid complications. This injection is intended for use under medical supervision in hospital settings, ensuring appropriate monitoring of maternal vital signs and uterine tone during therapy.