Cannabidiol (CBD) is a non-intoxicating compound extracted from the Cannabis sativa plant. It has gained widespread attention for its potential to affect various bodily functions without causing the “high” associated with THC. Motion sickness, medically termed kinetosis, is a common disturbance of the inner ear that causes symptoms like nausea, vomiting, and dizziness during travel. This article explores how CBD might interact with the body’s systems to address these symptoms.
The Physiology of Motion Sickness
Motion sickness arises from a disagreement between the sensory inputs the brain receives about the body’s position and movement. The sensory conflict theory posits that this condition is triggered when the visual system and the vestibular system send conflicting signals. The vestibular system, located in the inner ear, senses motion, gravity, and spatial orientation.
For example, when a person reads a book in a car, their eyes send a signal of stillness to the brain while the inner ear detects the car’s movement. This sensory mismatch confuses the brain’s central processing centers, which then relay a distress signal to the vomiting center in the brainstem. Symptoms often include cold sweat, headache, and intense nausea.
How CBD Interacts with Nausea Signals
The theoretical benefit of CBD for motion sickness centers on its interaction with the body’s endocannabinoid system, a complex network that helps regulate numerous processes. CBD does not directly activate the main cannabinoid receptors, but it does interact with other crucial signaling molecules in the brain.
One significant pathway involves the neurotransmitter serotonin, which plays a large role in triggering nausea and vomiting. CBD interacts with the 5-HT1A and 5-HT3 serotonin receptors, which control the emesis reflex. By indirectly activating 5-HT1A autoreceptors, CBD can reduce the release of serotonin in forebrain areas that mediate nausea. Additionally, in laboratory models, CBD has acted as a negative allosteric modulator of the 5-HT3 receptor, a common target for conventional anti-nausea medications. These dual actions suggest CBD may help suppress the neural signals that initiate sickness.
Reviewing the Scientific Evidence
While the mechanism of action related to serotonin signaling is promising, direct, large-scale human clinical trials specifically investigating CBD’s effect on motion sickness are currently lacking. Scientific evidence largely stems from preclinical animal studies and human trials focused on other causes of nausea, such as chemotherapy-induced nausea and vomiting (CINV). In animal models, CBD has demonstrated anti-emetic effects, suppressing both vomiting in shrews and nausea-like behaviors in rats.
These studies suggest the compound is effective for suppressing toxin-induced symptoms. Extrapolating these findings to kinetosis suggests a potential benefit, as the endpoint symptom—nausea—is the same regardless of the trigger. Early human research, often involving combined CBD and THC products for CINV, has indicated a reduction in nausea and vomiting when used alongside standard anti-nausea medications. However, the results are preliminary, and the exact efficacy of CBD isolate alone for motion sickness requires dedicated research.
Practical Usage and Safety Guidelines
For acute conditions like motion sickness, the method of CBD administration affects the onset time of effects. Oils and tinctures, taken sublingually, offer quick absorption, with effects typically beginning within 15 to 45 minutes. Capsules or edibles must pass through the digestive system and may take 60 to 90 minutes or longer to become fully effective. Taking a tincture 30 to 60 minutes before travel is a common strategy.
Starting with a low dose and gradually increasing it is recommended to gauge individual response and minimize potential side effects. The most commonly reported side effects of CBD include tiredness, dry mouth, and diarrhea. Of greater concern is the potential for CBD to interact with other medications, especially those metabolized by the liver’s cytochrome P450 enzymes, which include some conventional motion sickness drugs. Anyone considering using CBD should consult a healthcare provider to discuss possible drug interactions and safe dosing guidelines.