K2 is a synthetic cannabinoid that is often sprayed on herbs and smoked, producing effects similar to marijuana. It originated from research done by a chemist but has become an unregulated substance that is very dangerous due to unknown toxic contaminants. While currently legal in most states, K2 has been linked to severe health issues like seizures, coma, and death. Several states and the DEA have moved to ban its chemicals and the substance is under review to be added to the controlled substances list.