One of the best remedies for motion sickness is cannabis. A recent study found that 96% of individuals who consumed cannabis flowers and concentrates reported symptom relief.
The chemical compounds in weed bind to molecules found in the brain, including neurotransmitter receptors. These receptors activate when the chemicals are introduced to the body.
The Endocannabinoid System
A little-understood system in your body, the endocannabinoid (ECS) system, regulates several vital bodily functions, including sleep, mood, appetite, body temperature, memory, learning, and pain signals. It does so by regulating nerve cell signaling at junctions called synapses.
When a neuron is stimulated, it synthesizes and releases endocannabinoids, which are long-chain polyunsaturated fatty acids (similar to those found in your own body) such as anandamide and 2-arachidonoylglycerol (2-AG). These lipid-based retrograde neurotransmitters then bind to cannabinoid receptors within the brain.
Cannabinoid receptors come in two varieties: CB1 and CB2. CB1 is mainly found in the central nervous system, whereas CB2 is found throughout the body, especially in immune cells. When a cannabinoid binds to either of these receptors, it triggers different effects, depending on where the receptor is located and which endocannabinoid it binds to.
For instance, if you smoke high THC content, the THC activates CB1 receptors, which influence the dorsal vagus complex, a nerve crucial in controlling nausea. If the THC level in cannabis is too high, this can cause cyclical vomiting syndrome (CVS), which requires hospitalization and treatment for dehydration and other complications.
While it seems counterintuitive that a drug designed to reduce nausea would cause vomiting, the answer lies in the overstimulation of these receptors, leading to a cascade of events that disrupts the standard brain-gut circuitry mediating emesis. This is why it is essential to choose a low-THC, high-CBD cannabis strain for nausea.
The CB1 Receptors
The brain’s CB1 receptors bind to endocannabinoids and act like traffic cops to control the levels and activity of most other neurotransmitters. They’re densely packed throughout the cerebellum, basal ganglia, and hippocampus, influencing memory processing, pain regulation, and motor control.
Cannabis’ psychoactive ingredient, THC, attaches to CB1 receptors in the central nervous system and stimulates them. This causes an acute rise in dopamine and the characteristic “high” associated with cannabis use. However, overstimulation of this receptor produces nausea and vomiting in some people. This is known as cannabis hyperemesis syndrome (CHS).
Research suggests that cannabis formulations with high THC content or prolonged exposure to hot environments can trigger CHS. The symptoms can include nausea, abdominal pain, and uncontrollable vomiting. This can lead to severe dehydration and may even be life-threatening.
Three licensed cannabinoid medicines contain a compound that activates both CB1 and CB2 receptors to suppress nausea and vomiting produced by chemotherapy. Several studies report that nabilone is at least as effective as the antiemetic prochlorperazine in reducing CINV. Research is continuing to understand how will cannabis help with nausea and vomiting. One possible mechanism involves the activation of the ECS by THC, which then triggers a chain reaction that causes the release of endocannabinoids, including anandamide and 2-AG, which act as natural anti-nausea agents.
The CB2 Receptors
Many cannabis products contain cannabinoids other than delta-9-tetrahydrocannabinol (THC). These compounds can have powerful therapeutic effects, including reducing nausea and vomiting. They do this without producing the high associated with delta-9-THC. These nonpsychoactive compounds can help alleviate the side effects of chemotherapies and other conditions that cause nausea and vomiting.
The CB2 receptors in immune cells and brain areas influence memory processing and pain regulation. Traditionally, it was thought that the CB2 receptors did not have psychoactive effects, but research now shows that they do play a role in reducing nausea and vomiting.
Cannabis, like the other plants of the hemp family, produces an abundance of phytocannabinoids that are absorbed into our bodies. These phytocannabinoids can activate the endocannabinoid system and produce endogenous cannabinoids that act as natural neurotransmitters that regulate many of our body’s functions.
Long-term cannabis use can lead to cannabis hyperemesis syndrome (CHS), characterized by severe and uncontrollable nausea and vomiting. CHS is believed to develop when the body’s endocannabinoid receptors become overstimulated. Only a small number of people who regularly use cannabis develop this condition. In most cases, the symptoms of CHS disappear within days or months after stopping cannabis use.
The CB3 Receptors
The CB1 and CB2 receptors are not the only cannabinoid receptors in the endocannabinoid system. There is a third one, G protein-coupled receptor 55 (GPR55) or – more commonly known – the “orphan” receptor. Researchers now know that various ECS ligands, including anandamide, bind to the GPR55. It’s also been shown to be involved in regulating blood pressure and regulating intraocular pressure.
The GPR55 receptor has a specific role in nausea called anticipatory vomiting, associated with some chemotherapy treatments. This condition responds well to cannabis, lessening episodes’ frequency and intensity.
It’s also been shown that the GPR55 receptor regulates appetite, and some studies support the use of cannabis to stimulate appetite in patients with HIV who experience AIDS-related wasting syndrome. However, these studies are mainly anecdotal.
