Morphine is the most widely used analgesic for pain control. It is a highly addictive narcotic drug used to relieve moderate to severe pain. It is derived from opium poppy Papver Somniferum that binds to opiate receptors which directly changes the feelings of chronic morphine users. Morphine displays an effect on the mesolimbic pathway, resulting in an increase in dopamine levels which causes the activation of the reward system. Prolong use of morphine results in the craving of the drug. The individual then develops an addiction becoming dependent and then consumes opiates in excess to counteract the withdrawals when an absence of opiate occurs. A condition called morphine tolerance then develops. A higher dose of morphine is then needed to achieve the same analgesic effects due to the decrease of the drugs tolerance in a person. Chronic usage of morphine exhibits a few side effects including an increase in oxidative stress, cell apoptosis, neuronal dysfunction and toxicity. One of the mechanisms proposed that lead to withdrawal and dependency is caused by an accumulation of free radicals leading to the abundance of oxidative stress. This in turn will lead to neurotoxicity and cell death within the brain due to chronic morphine administration over a prolong period of time.