Marijuana causes a dry mouth because it blocks the glands that produce saliva.
Cotton mouth, also known as “the pasties”, is a side effect of marijuana that causes a dry mouth. While having a dry mouth can be unpleasant, there are some remedies that can help reduce the symptoms.
Marijuana causes cotton mouth because THC, the active ingredient in marijuana, binds to receptors in the salivary glands and causes them to be less active.
Here, we examine the science behind marijuana and cotton mouth, and go over some preventative measures and home remedies for this common side effect.
Marijuana and Dry Mouth
Dry mouth, also called xerostomia, is a common side effect of many drugs and medications, including marijuana. The effect is thought to be dose-dependent, meaning it is stronger if you consume more marijuana.
In the past, some people believed that cotton mouth was caused by inhalation of irritating smoke. However, we now know that marijuana affects the salivary glands directly. This explains why you can get cotton mouth even if you vaporize or eat your marijuana.
The endocannabinoid system
Marijuana causes a dry mouth because of the way it acts on the endocannabinoid system.
The endocannabinoid system is composed of cannabinoids and cannabinoid receptors. Cannabinoid receptors are found in many pathways in the body, and have diverse effects. They can respond to both plant cannabinoids, such as those found in marijuana, or endogenous cannabinoids found in the body.
The endocannabinoid system is thought to regulate the way other systems in the body work.
Marijuana inhibits saliva production
Cannabinoid receptors are found on the submandibular glands — a pair of glands located beneath the floor of the mouth that are responsible for producing about 70% of our saliva.
When THC binds to these receptors, messages from the parasympathetic nervous system that normally tell the submandibular glands to produce saliva are blocked. This means the glands produce less saliva, resulting in a dry mouth.
Interestingly, cannabinoids are believed to block messages from the parasympathetic nervous system in two ways, by binding to receptors in salivary glands as well as receptors in the brain where the signals originate from.
How To Prevent Dry Mouth
While dry mouth is unpleasant, there are a few remedies and preventative measures you can try to minimize its impact.
Having enough saliva is important because it plays a role in eating and digestion. Not only does saliva lubricate food and help it go down the esophagus, it also starts the process of digestion of starches in our food.
It’s especially important for marijuana smokers to have enough saliva, because an increased appetite, or “the munchies” is another side effect of using marijuana.
Since dry mouth is dose-dependent, it’s important to get the dose right to avoid side effects. A good rule of thumb is to use the minimum dose required to give you relief, without causing side effects.
If you do come down with a case of cotton mouth, make sure to have water available to wet your mouth. Using a straw can help too, because the sucking action stimulates the salivary glands.
Alcohol, coffee, and tea can all make a dry mouth worse, so stick to plain water where possible. You can also increase saliva production by sucking on a candy or lozenge, or chewing gum.
Make sure to be careful when eating if you have a dry mouth — it can make swallowing more difficult. It’s best to drink water while eating if you are experiencing these symptoms.