Edible cannabis products offer an alternative to inhalation, delivering physical and psychoactive effects as they are absorbed through the digestive system. Users sometimes report a localized sensation in the mouth and throat, often described as numbness, tingling, or a scratchy feeling shortly after ingestion. Determining if this is true localized numbness requires distinguishing between an anesthetic effect and the physical sensation caused by the compounds themselves.
The Specificity of the Sensation
True localized numbness, defined as a complete loss of sensation, is generally not a documented side effect of standard edible consumption. The sensation often interpreted as numbness is more accurately described as a tingling, burning, or scratchy irritation of the mucosal lining. This immediate feeling can be confused with a numbing effect because it is unusual and distracting.
A significant contributor to throat discomfort is xerostomia, commonly known as dry mouth, which is a well-known effect of cannabis compounds. The reduction in saliva production causes the throat to feel dry, sticky, and scratchy, which some users may perceive as a strange or reduced sensation. This dryness can progress to a sore or irritated throat if not addressed with hydration. Therefore, the resulting effect is typically irritation and dryness, rather than a true anesthetic block of nerve function.
How Cannabinoids Interact with Local Nerves
The localized sensations in the mouth and throat are often linked to the interaction of concentrated cannabinoids with specific receptors in the oral and pharyngeal mucosa. The endocannabinoid system, which includes the CB1 and CB2 receptors, is present throughout the body, including sensory nerves. Cannabinoids like delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) can interact with these receptors to modulate various processes, including pain and inflammation.
A more direct explanation for the burning or tingling sensation involves the Transient Receptor Potential Vanilloid 1 (TRPV1) channel, a type of ion channel found on sensory nerve endings. TRPV1 is often referred to as the “capsaicin receptor” because it is activated by the compound that makes chili peppers spicy, mediating the sensation of heat and pain. Studies show that certain cannabinoids, particularly CBD, are agonists of the TRPV1 channel, meaning they activate it.
When high concentrations of cannabinoids from an edible pass over the mucosal linings of the mouth and throat, they can directly stimulate these TRPV1 channels. This activation generates a signal that the brain interprets as a burning or warm sensation, similar to mild spice, which then causes the tingling or irritation. The sensation may be more pronounced when high-concentration extracts are used in the edible formulation. The effect is a chemical irritation of the sensory nerves, not a systemic numbing agent.
Non-Cannabis Related Causes of Oral Irritation
While cannabinoids themselves can cause sensory changes, the composition of the edible product often contributes to throat irritation in ways unrelated to the active compounds. Many edibles are made using concentrated cannabis extracts, such as oils or tinctures, which can contain residual plant matter or other compounds that are naturally irritating to sensitive tissues. These concentrated oils can cause a chemical irritation or a burning sensation simply by coating the throat.
Several non-cannabis components commonly found in edibles can cause irritation:
- Highly acidic ingredients, such as citric acid or malic acid, are often used to enhance flavor or mask the natural taste of the cannabis extract, and these components can temporarily irritate the delicate mucosal lining.
- Residual alcohol, if the cannabis extract used was alcohol-based, can create a burning or stinging sensation upon contact with the throat tissues.
- Improperly refined extracts or low-quality products may contain residual solvents left over from the extraction process, which act as chemical contaminants that irritate the throat.
- Common food ingredients, including certain artificial sweeteners, flavorings, or emulsifiers such as soy lecithin, can trigger mild allergic reactions or localized irritation in sensitive individuals.