The XX Factor

Sorry, Guys, the Pot You Smoke Isn’t Going To Make You Skinny

There is potential for weight-loss in this field, but not in the way you are hoping.


Earlier this week, Telegraph science correspondent Richard Gray set the pot-o-sphere on fire with this one sentence:

Researchers have discovered two compounds from cannabis leaves that can increase the amount of energy the body burns.

You might infer from that line that researchers have discovered that these two chemicals speed up metabolism in the human body, but that remains to be seen. So far, the drugs have only been shown to increase metabolism in rodents.

That didn’t stop the breathless follow-up coverage. “Pot May Treat Obesity-Related Diseases,” exclaimed UPI. “Can Weed Treat Obesity?” asked the Village Voice. “That Weed You’re Smoking May Actually Help Protect Your Fat-Curdled Organs,” speculated Jezebel.

This is a great example of how mediocre science writing gets spun into downright misinformation—good for page views, terrible for scientific literacy. The headlines referencing pot, ganja, and cannabis have excited marijuana enthusiasts, but as far as we know, plain old marijuana does not cure obesity or metabolic syndrome, and nobody’s trying to prove that it does. The news is that a UK pharmaceutical company is studying the effects of just two chemicals derived from specially-bred marijuana plants in patients with obesity and metabolic syndrome.

Ironically, the chemicals in question calm a major cannabinoid receptor, rather than stimulate it. Marijuana, as you may have heard, tends to increase appetite. Researchers hope that a drug that dampens cannabinoid signaling could have the opposite effect.


There’s reason for this hope: Some drugs that decrease cannabinoid signaling have been shown to reduce weight and appetite in rodents and humans. Cannabinoid receptors have also been found in fat and the liver, which might explain why GW Pharma’s compound THCV improved metabolic abnormalities associated with cardiovascular disease and diabetes in animals.

GW Pharma may be developing a weight-loss blockbuster. Or it could be another bust like rimonabant, a cannabinoid antagonist by Sanofi-Aventis that helped patients lose weight and improve their metabolic profiles, but also appeared to increase the risk of depression, and possibly even suicide. That’s the catch: Pot tends to make people hungry and happy. Dampening that signal may leave you with thinner but sadder patients. GW Pharma hopes that its product will avoid the pitfalls of rimonabant because it affects the cannabinoid receptor differently.


This is all really interesting. But keep in mind that the company is still in the early stages of human testing. Results from the Phase IIa clinical trials aren’t expected until the end of the year. It’s not clear why Gray decided to write his story now. Usually this kind of piece is pegged to the publication of new findings or to a milestone in drug development, like the start or end of a clinical trial. But the rodent results aren’t new and the clinical trials aren’t done yet. The only thing we know right now is the same thing we knew last month and last year: The weed you’re smoking is not going to help you lose weight.