For a comprehensive discussion of the topic, see my article on Civilized.
Cannabis has long been known to treat nausea and vomiting. After all, Dronabinol is a cannabis-based FDA-approved medication to help treat nausea associated with chemotherapy. So can cannabis also make you vomit?
Turns out, in some cases, it can. Cannabinoid hyperemesis syndrome (CHS) is an increasingly more common condition characterized by repeated bouts of stomach pains, nausea, and vomiting. It’s thought to be the result of chronic heavy cannabis use for years.
This seems like a paradox. However, THC, the psychoactive chemical in cannabis that makes you stoned, can have pro-vomiting effects by blocking the stomach from emptying its contents, but for most people, these effects are overridden by its anti-nausea effects in the brain.
There are 3 leading hypotheses for the cause of CHS:
- THC’s anti-nausea effects, by acting on CB1 receptors in the brain, become weaker, while its pro-nausea effects, by acting on CB1 receptors in the gut are unaffected.
- THC’s general effects are weakened, but there’s an increase in signaling strength of pro-nausea cannabinoids like cannabidiol and cannabigerol.
- Over time, the toxic effects of pesticides and molds on the cannabis flowers build up and lead to pain and vomiting.
So what can be done?
Stop using cannabis. Symptoms will eventually go away when you stop using.
In the meantime, sufferers from CHS find relief in taking hot baths and showers, but these only provide short-term relief. The benefits of hot water results from the activation and desensitization of pain pathways mediated by heat-sensitive TRPV1 receptors that lead to stomach pains and vomiting. However, recent reports suggest that capsaicin cream (the same chemical found in spicy foods that cause your mouth to feel like it’s on fire) can relieve the pain associated with CHS. The benefits of this cream similarly stem from activating TRPV1 receptors, which quickly deplete neurotransmitters that contribute to the pain response.
Note: a report published this morning (1/13/18) suggests that 33% of heavy cannabis users have, at some point, experienced symptoms of CHS. One caveat is that the data in this report was generated from emergency room patients, perhaps leading to an overestimation of CHS prevalence but illuminating a possible link between elevated CHS risk when other health conditions are present.
For more detailed information, see my full article on Civilzed