Keygraf 2 Capsule contains Tacrolimus 2 mg, an immunosuppressive agent primarily indicated for the prevention of organ transplant rejection. Tacrolimus acts by inhibiting calcineurin, thereby suppressing T-lymphocyte activation and proliferation, which plays a critical role in the immune response. This mechanism helps reduce the risk of acute and chronic rejection in patients who have undergone kidney, liver, or heart transplantation. Keygraf 2 Capsule is administered orally, with dosing individualized based on patient weight, organ type, and therapeutic drug monitoring to maintain optimal blood concentrations and minimize toxicity. Common adverse effects include nephrotoxicity, neurotoxicity, hypertension, hyperglycemia, and increased susceptibility to infections. Regular monitoring of renal function, blood glucose, electrolytes, and tacrolimus blood levels is essential during therapy. Caution is advised when co-administered with drugs that affect cytochrome P450 enzymes due to potential drug interactions. Keygraf 2 Capsule should be used under strict medical supervision, with careful consideration of the benefit-risk ratio, especially in patients with pre-existing renal impairment or those receiving concomitant nephrotoxic agents. Proper adherence to prescribed dosing and monitoring protocols is crucial to maximize efficacy and minimize adverse effects.