Opium is a plant containing opioids which reduce pain by binding to opioid receptors. Cannabis is a plant containing cannabinoids which produces a diverse range of effects by acting on cannabinoid receptors. The Drug Enforcement Agency lists several opioids including heroin as schedule I drugs. They also list all cannabis, hemp, and cannabinoids as schedule I drugs. This means the DEA sees cannabis and heroin as comparable threats to society that offer no medical benefit. So, what is the difference between opioids and cannabis, and why would someone choose to treat their pain with one over the other?