Both the drugs Heroin and Methamphetamine affect the brain differently, but are equally powerful. Heroin belongs to the opioid family, which blocks the pain receptors and mimics the brain’s natural feel-good hormones. Due to heavy use, over time, the brain stops creating these chemicals naturally. On the other hand, Methamphetamine floods the brain with extreme dopamine, the chemical responsible for reward and motivation. While one drug slows down the body, another speeds up the body. Both alter the brain’s communication system, making the cycle of addiction more difficult to quit without taking any professional treatment help.