The aim of this study was to analyze the antagonistic potential of leucine on ?-opioid receptor by computational studies. Studies has shown that drug addiction has reached epidemic levels across the globe with approximately 247 million drug users worldwide. Heroin binds to and stimulate the ?-opioid receptor thereby inducing the release of neurotransmitter dopamine, triggering excessive drug taking behavior. The life-threatening side effects of the current ?-opioid receptor drugs (Suboxone and Naloxone) such as Asthenia, Insomnia, Rhinitis, Infections, Pain, Headache e.t.c necessitate the discovery of novel potent and safe compounds as a therapeutic approach in the treatment of drug addiction. In view of this, computational tools were adopted to out-source better antagonist for ?-opioid receptor as a drug-gable target. The Leucine chemical compound was retrieved from PubChem database and was screened for its inhibitory potential on ?-opioid receptor, which was retrieved from protein data bank repository. PyRx AutoDock Vina option based on scoring functions was used to perform Computational docking analysis and the target was validated in order to ensure that the right target and appropriate docking protocol was used for this study. Leucine was found to have a better binding affinity with the target (-4.7kcal/mol) when compared with the co-crystallized molecule (-2.5kcal/mol). Leucine has a molecular weight (MW) of 131.174 g/mol, number of hydrogen bond donor is 2, number of hydrogen bond acceptor is 3, LogP is -1.864 and number of rotatable bond is 3. Docking studies and ADME/T (Absorption, Distribution, Metabolism, Excretion and Toxicity) properties of leucine on ?-opioid showed that this ligand is a druggable molecule when docked well with ?-opioid. Therefore, Leucine plays an inhibitory role on ?-opioid receptor and thus should be implicated as a potential agent in the treatment of drug addiction.