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Why Smoking Cannabis Causes a Dry Mouth

It’s a question most cannabis users have probably asked at some point – why does smoking weed mean a dry mouth? If you’ve ever experienced this during or after a smoke, you’re not alone. 

Marijuana users know that dry, sticky sensation on your tongue and the roof of your mouth is unpleasant, but it seems to be part and parcel of the experience. Before you know it, that water you’re sipping is going to be slurped. But why does it happen, what does it mean, and what can you do about it?

What Cottonmouth is all About

One of the most common side effects of ingesting cannabis through smoking or vaping, cottonmouth, is as symptomatic of weed use as red eyes and the munchies. Casually referred to by many as cottonmouth, but medically known as hyposalivation or xerostomia[i] (zee-ro-stoe-meea), it can be simply described as reduced saliva and happens when your submandibular glands – a.k.a. saliva glands – don’t produce enough saliva to keep your mouth moist. 

Some prescription or over-the-counter medications cause it. But it’s commonplace among smokers, vapers, and those who consume edibles and other cannabis products.

Although xerostomia can indicate other medical issues such as gum disease, if you’ve been smoking weed, chances are that’s what’s caused your dryness. There’s a range of saliva secretion that is deemed ‘normal’ – around 1.5-2.0 millilitres per minute. Medical diagnosis of hyposalivation (low saliva flow) is made when your flow rate drops below 0.5-0.7 millilitres per minute[ii].

How Cannabis Causes A Dry Mouth

Cottonmouth occurs due to the interaction between the cannabinoids THC, CBD (and the various others) and the endocannabinoid system in the human body. Which we know contains numerous cannabinoid receptors. Cannabinoid receptors are located in the salivary glands inside the mouth. When THC and anandamide bind to these receptors, it essentially reduces saliva production. It blocks signals from the parasympathetic nervous system to keep generating saliva. In other words, THC effectively puts saliva production, or salivation, on standby.

Several medical studies have analysed the relationship between smoking weed and cottonmouth. They have found that smoking cannabis does have a pretty significant effect on oral health, as one would imagine. Concerning cottonmouth, a 2012 study at the State Key Laboratory of Molecular Biology in Kiev noted that “CB1 receptors predominantly modulate the flow of saliva, while CB2 receptors seem to influence consistency and content of saliva (such as sodium levels).”[iii]

Does A Dry Mouth Mean Dehydration?

A good question, with a fascinating answer!

Among the conclusions presented by the Kiev study was that dry mouth from consuming cannabis does not cause dehydration through the rest of the body. This makes a degree of sense considering that cottonmouth is merely the symptom of salivary glands operating at a lower-than-normal clip. The study added that this explains why cannabis consumption doesn’t come with the same type of hangover caused by alcohol consumption.

Why You Should Fight Cottonmouth

You may write off cottonmouth as an inevitable part of the smoking experience – but it’s definitely best that you don’t. Dry mouth from cannabis consumption can yield chronic results, which can include the following[iv]:

  • Leukoedema – a white or grey lesion in the mouth
  • Candida Albicans – oral thrush
  • Periodontal Disease – gum infections, bad breath, loss of teeth, sensitive teeth and receding gums
  • Tooth Decay
  • Sore throat

Remember that not only does saliva lubricate the mouth; it also protects the mouth from bacteria and other microorganisms. If you’ve got cottonmouth, take steps to alleviate it for the sake of your oral health!

How to Combat Cottonmouth

As a smoker, protecting your oral health is paramount. The good news is that it’s not rocket science. There are plenty of easy ways for you to combat that dreaded cannabis cottonmouth.

  1. Drink, but choose water. It may be tempting to opt for a nice cold beer or a soft drink, but these types of drinks can dry the mouth out even more. The same goes for black teas or coffee – anything that contains tannins is doing your more harm than good in this battle. As with anything, water is your best friend in this instance, drinking water regularly will keep your mouth nicely lubricated.

2. Chewing gum can stimulate the activation of saliva. Keep a sugary pack handy.

3. Lollipops and hard candy like fruit drops do the same job – with sour-tasting candies thought to be the best for stimulating those saliva glands.

4. Herbal Tea can help reduce the dry feeling further back in the throat. They’re also really hydrating.

5. Oral Sprays or mouthwashes are available over the counter from any Pharmacy.

Lastly, it would make sense to avoid anything else that could dry out the mouth. Like salty snacks like potato chips and peanuts or carby foods like pizza. In other words, the things a lot of us crave the most after a smoke!





Cultivation information, and media is given for those of our clients who live in countries where cannabis cultivation is decriminalised or legal, or to those that operate within a licensed model. We encourage all readers to be aware of their local laws and to ensure they do not break them.

This post is also available in: French

Duncan Mathers