Why does cannabis increase appetite?

Yes, cannabis increases appetite. It's an effect produced by THC, which activates the CB1 receptors in the brain, raises levels of ghrelin (the hunger hormone) and intensifies smell and taste. It's known as the “munchies” and can boost caloric intake by up to 40% (1). Below we explain why it happens, which cannabinoids are involved and whether CBD also has this effect.

One of the best-known features of cannabis use is that it increases appetite, commonly known as the “munchies”. Is it true what they say about cannabis? Which compound in cannabis makes appetite go up? Do Cannabis sativa users always get the munchies? Does CBD also increase appetite? We explain.

Cannabis and the sensation of hunger: what are the “munchies”?

You ate not long ago, you smoke a joint and, suddenly, you can't resist a snack before dinner. Sound familiar? Cannabis increases appetite, a phenomenon commonly known as the “munchies”, which happens mainly because of the action of THC (tetrahydrocannabinol), the main psychoactive compound in the plant.

THC interacts with the brain receptors that control hunger, making you feel intense cravings to eat.

In fact, one of the medicinal uses of THC is to increase food intake in patients with loss of appetite or anorexia. So yes, it's true: cannabis really can whet your appetite.

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The scientific process behind the munchies

When people use cannabis, they often feel intensely hungry, even if they have eaten recently. This phenomenon has intrigued users and scientists alike.

The endocannabinoid system and the CB1 receptors

The answer to why cannabis makes you hungry lies in its chemical composition, specifically in the cannabinoids, and in their interaction with the endocannabinoid system of the human body.

THC acts on the cannabinoid receptors in the brain, located on neurons, particularly on the CB1 receptors. These receptors are part of the endocannabinoid system, a network of neurotransmitters that regulates several physiological functions, appetite among them.

Scientific research has shown that THC acts on the neurons of the hypothalamus, a region of the brain that controls hunger and satiety, increasing the production of hormones and neurochemicals related to the sensation of hunger.

THC, smell and the pleasure of eating

In addition to affecting the hypothalamus, THC also enhances the sensitivity of our senses, especially smell and taste. Studies have indicated that activation of the CB1 receptors can intensify the pleasure derived from eating, making food more attractive and desirable.

THC and ghrelin, the “hunger hormone”

Another important factor is that THC raises the body's levels of ghrelin, a hormone secreted in the stomach known as the hunger hormone because it stimulates appetite.

One study showed that cannabis acts as an appetite stimulant, increasing daily caloric intake by up to 40% (1).

Uses of medicinal cannabis to stimulate appetite

Cannabis's appetite-boosting effect has important implications for medicinal cannabis. Possible applications include its use in patients with conditions that cause loss of appetite or cachexia, such as cancer, HIV/AIDS or eating disorders. In these cases, THC can help stimulate appetite and improve the patient's quality of life.

Does CBD also increase appetite?

The short answer is no, CBD does not cause the munchies. Unlike THC, cannabidiol is not a direct agonist of the CB1 receptors, so it does not trigger the intense hunger sensation typical of psychoactive cannabis.

That said, the effects of CBD on appetite are complex and the scientific evidence is still mixed:

• A systematic review of 11 clinical trials published in 2022 concluded that CBD has a predominantly anorexigenic effect (appetite-reducing), although some studies found no significant change and one reported an increase in appetite (3).
• CBD appears to modulate the endocannabinoid system indirectly, without activating the CB1 receptors or sustainably raising ghrelin levels.
• A recent trial in healthy adults observed that a single 298 mg dose of CBD increased caloric intake by around 193 kcal compared to placebo, despite reducing ghrelin levels —the opposite pattern to THC— (4).
• In paediatric epilepsy patients treated with pharmaceutical CBD, both decrease and increase in appetite have been described as side effects, confirming individual variability.

In short, CBD does not produce the compulsive hunger effect associated with THC, but its impact on appetite is not entirely neutral and depends on dose, treatment duration and individual response. Modulation of the endocannabinoid system, anxiety reduction and antiemetic effects are the most likely mechanisms behind its indirect effects on eating behaviour.

Munchies and cannabis: what science says

Being aware that cannabis use can increase our food intake —especially of the less healthy options, because of the pleasure of eating them when smell and taste are heightened— can help us better understand the eating behaviour we have when under the effects of THC.

The appetite-boosting effect produced by THC is physiological and it's likely that all consumers experience it to a greater or lesser extent (2). For some, this is one more reason, alongside THC's effects on the brain, to consider reducing or quitting cannabis with THC.

On the other hand, interestingly, the data show that cannabis users are not more overweight than non-users, which implies a complex mechanism between cannabis-induced increased appetite and weight control. Understanding these mechanisms could open the door to new therapies for treating appetite disorders.

Next time you wonder whether cannabis makes you hungry, you'll know that a complex chemical interaction is behind this rather peculiar phenomenon. Bon appétit!

Frequently asked questions

Which cannabinoid increases appetite?

THC (tetrahydrocannabinol) is mainly responsible for the increase in appetite associated with cannabis. It acts on the CB1 receptors in the hypothalamus and raises levels of ghrelin, the hunger hormone. CBN has a mild stimulating effect, while THCV reduces appetite at low doses.

How long does the munchies effect last?

The munchies usually appear between 30 minutes and 2 hours after consuming cannabis with THC and can last between 3 and 6 hours, depending on dose, route of consumption (smoked, vaporised or edible) and individual tolerance.

Does CBD make you hungry?

CBD does not produce the munchies like THC, since it does not activate the CB1 receptors. The scientific evidence on its effect on appetite is mixed: most clinical trials suggest a neutral or slightly hunger-reducing effect, although some cases have reported an increase in appetite (3).

How can you avoid the munchies?

The most effective options to reduce the munchies are: lowering the THC dose, staying hydrated, having healthy snacks ready and respecting meal times. Strains with a high CBD-to-THC ratio tend to generate less compulsive hunger, since cannabidiol modulates the action of THC on the endocannabinoid system.

Sources

1. Foltin RW, Brady JV, Fischman MW. Behavioral analysis of marijuana effects on food intake in humans. Pharmacol Biochem Behav. 1986 Sep;25(3):577-82. PMID: 3774823.
2. Cuttler C, Mischley LK, Sexton M. Sex Differences in Cannabis Use and Effects: A Cross-Sectional Survey of Cannabis Users. Cannabis Cannabinoid Res. 2016 Jul;1(1):166-175. PMCID: PMC5576608.
3. Pinto JS, Martel F. Effects of Cannabidiol on Appetite and Body Weight: A Systematic Review. Clin Drug Investig. 2022 Nov;42(11):909-919. PMID: 36180814.
4. A single dose of cannabidiol increases ad libitum energy intake in healthy adults but does not affect postprandial glucose or lipid metabolism. PMID: 41825697.