Does Cannabis Cause Dehydration?

Humans are thirsty creatures.  The majority of the human body is water, and without it, dehydration sets in and we die.  Even though we can survive up to two months without food (I mean… I can’t), the human body can only last about a week without water.

Despite the immense importance of water, we don’t really know much about it.  For example, it’s unclear how much water we actually need, especially since our recommended daily water intake depends on variables cannabis cause dehydrationlike age, sex, pregnancy, and breastfeeding status.  According to the Institute of Medicine, a sufficient amount of water could range from about 3 cups for infants (as presented in breastmilk—you should not give infants plain water to drink; stick with breastmilk or formula) to 16 cups for breastfeeding women.  Don’t get too intimidated by that range if you’re not a water person, though. About 20% of our water intake comes from food.

Without having the science and specific numbers at hand, we all kind of know that water is a big deal.  It’s a concept that has been ingrained in our memories since childhood.  But this indoctrination isn’t working.

The majority of Americans are living their lives in a chronic state of dehydration

So when it comes to the relationship between cannabis and dehydration, it is far more likely that a cannabis consumer is already dehydrated prior to using cannabis than it is that cannabis is the cause of their dehydration.

The link between cannabis and dehydration stems from three main ideas: that cottonmouth is a sign of dehydration, cannabis is evil incarnate, and cannabis is responsible for a rare vomiting disease.

Is Cottonmouth a Sign of Dehydration?

It is intuitive to believe that cottonmouth (dry mouth), a common symptom of THC consumption is a sign of dehydration.  However, cottonmouth is actually one of the few negative consequences of cannabis’ interaction with our endocannabinoid systems (ECS). Our ECS is comprised of receptors CB1 and CB2, and THC has a high binding affinity for both.

While most of the time, cannabinoid interaction with these receptors promotes homeostasis and a general sense of well-being, it can create the very annoying sensation of dry mouth. According to a 2006 study, Both CB1 and CB2 receptors are located throughout different places in our bodies including the submandibular glands responsible for producing 70% of our saliva. When THC binds to a receptor within that gland, the gland temporarily loses its ability to receive messages from the nervous system telling it to produce saliva. Even though your mouth may make you feel dehydrated, your body is just confused about how much saliva it needs to produce.

The symptoms of cottonmouth can be alleviated by drinking lots of water, avoiding sugary, caffeinated, and/or alcoholic beverages, or just taking a break from cannabis

That Menacing Marijuana

The second reason that cannabis has been associated with dehydration stems from an unsubstantiated claim made by prohibitionists that cannabis is more dehydrating than alcohol.  The premise of that argument is that people are already dehydrated, so legalizing cannabis is going to make them even more dehydrated since metabolizing “toxins” like THC expedite the dehydration process.

There are several holes in this claim, though.  First, its classification of THC as a toxin demonstrates an ignorance of THC’s—and cannabis’ as a whole—incredibly therapeutic value for a range of medical conditions.  Second, claiming that cannabis is more dehydrating than alcohol because people are already dehydrated doesn’t actually explain how cannabis is uniquely more harmful than alcohol.  There is no research corroborating this assertion.  In fact, there is a paucity of research on cannabis and cannabis and dehydrationdehydration period.  However, there is a preponderance of evidence explaining alcohol’s inhibition of ADH—anti-diuretic hormone—or the hormone that stops us from peeing all day long.  The more alcohol you drink, the more you pee.  The more you pee, the less water you absorb.  Thus, dehydration.  While there is some evidence suggesting that cannabis is a diuretic in rats and possibly in humans, there is no evidence indicating that cannabis is causing people to eject water out of their bladders at a faster or more substantial rate than alcohol.

Given the disparity of evidence between alcohol and dehydration and cannabis and dehydration, it seems sort of scientifically reckless to make such an outstanding claim about alcohol’s superiority to marijuana.

Cannabinoid Hyperemesis Syndrome

Okay, so this part is going to be a bit polarizing, especially if you’re sitting in the marijuana-is-perfect-no-matter-what camp.  As the legalization of cannabis increases so has the diagnosis of cannabinoid hyperemesis syndrome.  This disorder is characterized by cannabis induced cyclic episodes of vomiting.  The people who seem to be at the greatest risk of this disease are those who have been smoking more than three times a day for an extended period of time.

Very little is understood about this syndrome

Prohibitionists love the idea of a cannabis induced vomiting disorder (finally, something that could maybe justify the demonization of cannabis!) while cannabis advocates remain divided about whether the thing even exists.  Those who have or know someone who has experienced CHS say that it is very real and debilitating and that awareness about its possibility is important.  Those who have not experienced CHS can be quick to condemn any mention of the syndrome as prohibitionist propaganda.  The reason it’s making an appearance in this article is because cyclic vomiting definitely does cause dehydration. And if CHS is truly a risk factor when consuming cannabis, then cannabis can lead to dehydration in those suffering from that condition.

What Really Matters

There’s a lot of mystery surrounding cannabis, but there are also a lot of facts we can lean on that can help us make the best decisions regarding cannabis use.

First, remember that research into cannabis and the endocannabinoid system is not new.  It’s decades old.  Arguably it’s much older than that if you count anecdotal evidence and cannabis’ use as a medicine for thousands of years.  While too much of any good thing can be bad (even water, y’all), you can take comfort in knowing that there is plenty of evidence supporting cannabis’ medical utility. If cannabis is a “toxin,” then that birthday cake I just ate is basically arsenic.

Second, our bodies are made for a lot more than just pot.  The type of food we eat, the amount of rest we get, the people we surround ourselves with, the choices we make… these are all things that contribute to our well-being, too.  Cannabis is wonderful, but it’s not the only thing that matters.

Finally, know that statistically speaking, you are probably dehydrated, and the reason for that is likely as simple as you not enjoying water enough to drink enough of it in a day.

I’m not judging you.  I’m a pregnant mother of a toddler.  My water intake takes less priority than my son’s attempts to eat his own poop.  Regardless of our awesome excuses, however, we can and should do better, especially since chronic dehydration can severely lower our quality of life.  So just drink more water, cannabis or no.

Dianna Benjamin

About the author: Dianna Benjamin is a freelance writer, teacher, wife, and mom horrified and fascinated by social justice and our inability--yet constant pursuit--to get it right.