The US National Institute on Drug Abuse (NIDA) is developing a way to chemically block the effects of cannabis. A "cannabinoid receptor antagonist" with the poetic name of SR141716 has been shown to produce a dose-dependent block against toking up.
A study published in the Archives of General Psychiatry detailed how 63 men received a dose of SR141716 or a placebo, and then smoked pot two hours later. The more SR141716 they received, the less the pot affected them.

Lead researcher Dr Marilyn Huestis said that the findings could help treat people "addicted to marijuana." Critics of the research complained that the chemical blocker could be forcibly given to people facing mandatory treatment for cannabis use.