How Does Weed Give You The Munchies?

If you’ve ever wondered exactly why smoking weed makes you want to devour a box of biscuits after 2 cheeseburgers and a packet of gummy worms, a team of neuroscientists may be one step closer to the answer. Here’s how weed gives you the munchies. 

The Research

Tomas Horvath, a neurobiology professor at Yale, together with his team of researchers, have a keen interest in how the brain controls feeding, appetite and fullness. A few years ago, he and Marco Koch from the University of Leipzig decided to conduct a study as to how the chemicals in cannabis interrupt normal brain function.

They discovered that a set of neurons in the hypothalamus literally get scrambled when exposed to cannabis and its active components. “When you administer cannabinoids to animals, as in humans, they start to eat more even if they’re full,” said Horvath.

The initial hypothesis of the study was that THC, the active cannabinoid in cannabis, would turn off these neurons, known as POMCs. However, their findings were quite the opposite: weed actually activated these POMCs to a very high degree.

POMCs secrete a chemical called alpha-melanocyte-stimulating hormone. This hormone is thought to play a role in our feelings of satiety – how full we get after consuming a meal. When mice were exposed to cannabinoids, POMCs star releasing completely different hormones: beta-endorphins, hormones which stimulate appetite and promote cravings.

“If you think about it, when you smoke marijuana or eat hashish cookies or whatever, obviously your brain functions change. That’s the whole idea behind them,” Horvath says with a laugh. “So the question is, are those brain functions changed because neuronal functions flip in other parts of the brain too? I think it’s an interesting question to ask.”

The researchers suggest that one cannot exclude the possibility of the olfactory senses playing a role in appetite, too. The munchies are a complex physiological response that can’t be reduced to a single set of neurons.

Another key finding may provide a clue as to why stoners aren’t all obese. While the production of the appetite-inducing hormone increases with cannabis use, the other, anti-feeding chemical is also produced. So once your high wears off, the alpha-MSH hormone is released again which could cause a rebound phase in which your appetite is dramatically reduced.

What is your go-to snack when you have the munchies?