Spit is underrated.

Even the word itself sounds gross, maybe even a little rude. In reality, saliva is essential to living. We need saliva to keep our mouth moist—another gross word—and to help us eat, talk, and breathe comfortably. Saliva is the first phase of digestion, as it helps break down carbohydrates. Most of us don’t really think about our saliva unless we have a salivary disorder, or unless we face the dreaded cotton mouth.

Cotton mouth, also known as dry mouth, is an unfortunate side-effect of consuming cannabis. That dry, sticky, uncomfortable feeling you get in your mouth after smoking a joint or eating an edible is all too familiar to many cannabis consumers, yet few of us know what causes it.

I previously thought smoke dries out our mouths. Eventually, I realized that you could also get cotton mouth if you consume cannabis in the form of tinctures or edibles, suggesting that cannabis, not smoke, is to blame.

So how does cannabis cause cotton mouth?

Firstly, let’s look at the bigger picture: the endocannabinoid system. Every mammal has an endocannabinoid system, which is affected by cannabinoids—the ‘active ingredients’ in cannabis. The endocannabinoid system affects our skin, nervous system, digestion, and many other organs and physiological functions within our bodies. It also affects our salivary glands.

Because saliva is so important, we have three main salivary glands: the parotid glands, sublingual glands and submandibular glands. Our submandibular glands produce around 60% of our saliva.

A 2004 paper used lab rats to investigate the phenomenon of cotton mouth. They found that the salivary gland known as the ‘parotid gland’ is affected by one of our cannabinoid receptors.

Similarly, a 2006 paper found that receptors in the submandibular glands were affected by THC. Anandamine, one of the most well-known endocannabinoids, seems to reduce the amount of saliva we produce. When we ingest cannabis, anandamine is ‘activated’, so to speak, and the salivary glands are put on pause.

Some people seem to suffer from cotton mouth more than others. So far, scientists aren’t too sure why this is. What we do know is that it seems that THC is the culprit when it comes to cotton mouth. If you want to avoid cotton mouth while still enjoying cannabis, low-THC strains might be your best bet.

If you’re still keen on high-THC strains, there are a few things you can do to reduce cotton mouth. Avoid caffeine, alcohol, and tobacco, as these all dehydrate your body and can decrease the amount of saliva you produce. Instead, keep sipping water, munch on some ice, and chew gum to help increase the production of saliva. There are also some medications available to treat dry mouth, so speak to your doctor if it becomes a chronic problem.

Something else to consider is avoiding smoking cannabis. While you can get cotton mouth no matter how you consume cannabis, some people find that it’s less severe when they use tinctures, vapes, or edibles as opposed to smoking. While the smoke isn’t the primary culprit of cotton mouth, it can make your mouth and throat feel uncomfortable, which can exacerbate the feeling. Consider switching over if you want to avoid drying out your mouth.

While cotton mouth can be unpleasant, the science behind it is fascinating. It’s a reminder that the endocannabinoid system has a far-reaching effect on many of our physiological processes, and a reminder that there are so many things we still don’t understand about the science of cannabis.


Sian is a writer, journalist and editor who covers cannabis, health, and social justice. Her work can be found on Healthline, Teen Vogue, Everyday Feminism, HealthyWay, HelloGiggles and more. Visit her website or follow her on Twitter.