Does Cannabis Cause Dehydration? 

by Haley Mills · January 6, 2023

Discover the truth about cannabis: does it really cause dehydration? Read this article to find out if marijuana use puts you at risk of dehydration and what you can do to stay hydrated.

A women drinking water while wondering does weed dehydrate you

Discover the truth about cannabis: does it really cause dehydration? Read this article to find out if marijuana use puts you at risk of dehydration and what you can do to stay hydrated.

Does Weed Dehydrate You?

People who smoke cannabis are likely familiar with cotton mouth, but does cannabis dehydrate you? It’s that dry mouth feeling that occurs right after smoking and may feel similar to the dehydration symptom of dry mouth for many people.

However, that doesn’t necessarily mean that weed causes dehydration. It’s a bit more complicated than that, so let’s break it down below.


Tetrahydrocannabinol (THC) is usually the leading cause of dry mouth, so it’s recommended to stick with cannabis strains high in CBD. Combined with adequate daily water intake, using CBD may reduce the chances of dehydration occurring after cannabis use.

The thirst sensation from weed results from low saliva production from THC binding to salivary glands rather than from losing bodily fluids. The THC binds to CB1 and CB2 receptors, which are located in the salivary gland. These cannabinoid receptors mediate THC effects, so the THC sends a message to slow the way we produce saliva, resulting in a dry mouth.

While rare, a person can develop Cannabinoid Hyperemesis Syndrome with extreme use of high THC products which can later result in dehydration and other adverse symptoms such as a weed hangover. It’s best to monitor use, read labels, and dose weed products correctly to avoid dehydration from marijuana consumption.

A dry mouth is not typically dangerous, but over time a decrease in the amount of saliva in your mouth could allow more bacteria to flourish, contributing to plaque, gum inflammation, and tooth decay. If you’re using marijuana and experience dry mouth, we recommend sugar-free gum or drinks, chewing on ice, using a cough drop, or cutting back to reduce the amount of THC in your system by reducing medical cannabis consumption.

Edibles vs. Smoking

While edibles won’t dehydrate you, it’s possible to become dehydrated if you consume too many edibles. Edible effects can last much longer than smoking or vaping weed, and it can be easy to forget to drink water. We recommend keeping a bottle of water with you when taking marijuana edibles.

If you are unsure, check your urine color. If it’s dark yellow, you should try to hydrate and drink more water throughout the day especially when smoking cannabis.

Smoking marijuana doesn’t dehydrate you, but it can dry your mouth. THC is known to cause increased feelings of thirst, but the effects are temporary and are not symptoms of dehydration. So, while smoking weed won’t cause you to lose fluids like alcohol or caffeine, it can make you thirsty, leading to more fluids and possible overhydration.

How Can I Recognize Dehydration?

Here are eight potential signs and symptoms of dehydration: 


When dehydrated, you may feel exhausted because dehydration affects all aspects of your health, including the sleep-wake cycles. Short sleep duration is significantly affected by inadequate hydration. Dehydration can also make you more tired and have less endurance during exercise.

Dark-colored or Low Urine

The urine will be darker, and you won’t pee much when dehydrated. Examining urine color is a standard way to identify dehydration. Darker-colored urine can occur when the body is conserving water and not releasing it, and it becomes concentrated with salt and other minerals. The ideal urine color is a pale yellow.

Skin Issues

One of the most common signs of dehydration is dry skin, cracked lips, and decreased skin elasticity. Doctors often use the skin turgor test to assess hydration status. The skin turgor test involves gripping or pinching the skin on the lower arm or abdomen between two fingers and releasing it after a few seconds. Hydrated skin will quickly return to its normal state, while dehydrated skin will take longer to bounce back to normal. 


You may experience frequent headaches with dehydration. Even though the condition is strongly linked to headaches, researchers aren’t sure how dehydration causes them. A prominent theory is that fluid depletion leads to the stretching of blood channels in the brain, which causes pressure and a subsequent headache. Some studies show that increasing water intake may help reduce symptoms in people with migraines.

Light-headed and Dizzy

Dehydration may cause you to feel dizzy and light-headed, especially when standing up from lying down or sitting. Dehydration can lead to orthostatic hypotension, which describes the sensation of lowering blood pressure when you stand or sit up. It is common among older adults, who are more at risk for dehydration and low blood volume. In some cases, severe dehydration may even lead to fainting.

Pounding Heart

Dehydration can cause cardiac symptoms like heart palpitations, pounding, fluttering, or an irregular heartbeat. Being dehydrated may negatively affect blood vessel function and alter blood pressure regulation. Dehydration can harm heart function during intense exercise by decreasing the amount of blood pumped out of the heart and reducing cardiac output.

Low Blood Pressure

Low blood pressure is a sign of severe dehydration. Dehydration causes low fluid circulating within your heart’s capillaries, veins, arteries, and chambers. When blood volume decreases, the body compensates by increasing the respiratory rate and reducing blood pressure. Low blood pressure can be dangerous, leading to shock and even death.

Altered Mental State

Dehydration can take an extreme toll on the brain and its ability to think and concentrate. Research has shown that dehydration can affect short-term memory, concentration, attention, energy levels, and mood. Many studies have also shown that dehydration can adversely affect mood and cognitive performance in both men and women. Severe dehydration can lead to an altered mental state, which may manifest as confusion and anger.

How Can I Manage Dehydration?

To effectively treat dehydration treatment, you must replace the lost fluids and electrolytes. The best approach to dehydration treatment depends on age, cause, and severity.

Over-the-counter oral rehydration can be used for infants and children dehydrated from diarrhea, vomiting, or fever. They are typically liquid solutions that contain water and salts to replenish fluids and electrolytes.

Most adults experience mild to moderate dehydration from diarrhea, vomiting, or fever can improve by drinking more water and other liquids with little to no sugar content. Diarrhea may get worse with fruit juice and sodas.

Cool water is your best bet when working or exercising outdoors during hot and humid weather. Sports drinks containing electrolytes can also be helpful.

Dehydration Diagnosis

Your doctor can often diagnose dehydration based on physical symptoms. If dehydration occurs, you will typically have low blood pressure, a faster-than-average heart rate, and reduced blood flow to your arms and legs. In severe cases, you may experience nausea, vomiting, and abdominal pain.

You may have undergone other tests, such as:

  • Blood tests. Doctors can use blood samples to check for electrolytes — sodium and potassium — and kidney function. 
  • Urinalysis. Urine tests can help show whether you’re dehydrated and can also check for a bladder infection.

Can Hydration levels affect your experience?

Yes, potentially. If you are dehydrated, the effects of cannabis may not be what you desire. For instance, you could develop a headache rather than feel the pain relief that you are used to feeling as an MMJ patient. It’s important to keep some water around and drink before and after consuming cannabis.

The Key Takeaways

So, does weed dehydrate you? No, smoking weed or taking edibles alone is not enough to cause dehydration, though it can result in some serious dry mouth. It’s smart to know the signs of dehydration and always keep water with you to hydrate periodically, especially if your plan is smoking marijuana at some point during your day. While THC can affect saliva production, that’s about the worst that will happen to marijuana users as long as they are healthy and hydrated.

Last Updated: January 30, 2024

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