Illustrated human body

Have you ever wondered what happens in your brain and body when you smoke marijuana or eat a pot brownie? The adverse effects are obvious, but what’s going on medically to cause those feelings? And why do other people have very different reactions to marijuana, such as increased anxiety or paranoia? What effect does marijuana have on the brain? What effects does marijuana have on the human body?

We asked two leading researchers in the field to walk us through the process from inhalation (or ingestion) through intoxication to coming down from your high since we were curious about the acute effects of cannabis for the occasional adult user. In this article we will discuss about what does weed do to your brain and body?

What Does Weed Do to the Brain?

Hundreds of different compounds are found in varied concentrations in the Cannabis sativa plant, depending on the strain and how it is cultivated. The psychoactive ingredient, delta-9-tetrahydrocannabinol, or THC, is the one that recreational marijuana users are most concerned about. The higher the THC level, the more powerful and possibly intoxicating the marijuana is.

According to Staci Gruber, Ph.D., associate professor of psychiatry at Harvard Medical School and director of the Marijuana Investigations for Neuroscientific Discovery program at McLean Hospital in Massachusetts, “because THC is the coveted compound, growers today breed plants to produce a lot of it.” Weed now is more than 300 percent stronger than it was in the mid-1990s.


“THC concentration has increased dramatically, but CBD and other elements that may attenuate THC’s harmful effects have decreased,” she adds. “The THC-to-other-compound ratio jumped from 14 to 1 to 100 to 1.” This ratio is significant because it determines how marijuana affects the brain and body.

Marijuana interacts with the endocannabinoid system, which is made up of substances and receptors found all over the body. “Endocannabinoid receptors are found in the liver, intestines, fat, vasculature, and every single cell and organ system,” says Daniele Piomelli, M.D., Ph.D., head of the University of California, Irvine’s Center for the Study of Cannabis. “However, the brain has the highest concentration.”

The endocannabinoid system, which is made up of chemicals and receptors located all over the body, interacts with marijuana. “Endocannabinoid receptors are located in the liver, intestines, fat, vasculature, and every single cell and organ system,” says Daniele Piomelli, M.D., Ph.D., director of the Center for the Study of Cannabis at the University of California, Irvine. “The brain, on the other hand, has the maximum concentration.”

Smoking Marijuana and Effects On the Body

So you smoked a blunt for a long time. Now what? The first thing to understand is that the effects of smoking marijuana differ from those of ingesting it. “The kinetics — the rate at which effects develop — are really quick when you inhale cannabis,” Piomelli explains. “It immediately enters the lungs, circulates via the heart, and ascends to the brain.” It also fades faster than when you use cannabis through other methods.”

The cardiovascular impact is the first thing you’ll notice. Piomelli states, “Blood pressure lowers.” “This prompts an instant response: the heart pumps more blood to restore normal pressure, and heart rate rises as a result.” These side effects are unpleasant, and they are the primary reason why individuals who take cannabis for the first time dislike it. They feel dizzy and afraid because their heart is racing, but such sensations pass rapidly.”

The high follows, when THC goes to the brain and activates CB1 receptors. “You get the reason why people use marijuana recreationally: the stoned experience of pleasure and intoxication that is specific to cannabis when you have enough THC in the brain to activate enough endocannabinoid receptors,” Piomelli explains. This procedure, according to Gruber, triggers the brain’s reward system, compounding the effect: “You receive a rush of dopamine that causes pleasure and makes you feel good.”

Edible Marijuana’s Effects On the Body

The chain of events is slightly different when cannabis is ingested as food, and it often takes 60 to 100 minutes to feel the effects vs only a few minutes while smoking, according to Gruber. Although the THC in that marijuana brownie avoids the lungs, it must be digested before it can be absorbed and given to the brain.

THC must first travel via the liver before reaching the brain. According to Piomelli, it is digested and transformed into 11-hydroxy-THC, which is a more powerful molecule than THC. The more powerful version then goes to the brain.

Women are far more efficient at producing 11-hydroxy-THC than men, which makes most women more sensitive to marijuana consumption. “It’s well knowledge that guys prefer cannabis over women, and it’s not because our brains are different,” Piomelli explains. “It’s primarily due to the fact that our livers are different, and women’s metabolisms are more active, so more 11-hydroxy-THC reaches the brain.”

Because THC is a fat-like chemical, it stays in the fatty brain for a long time. “The first high fades after a few hours, and one consequence is feeling hungry or having the munchies,” Piomelli explains. “However, this isn’t true hunger; rather, it’s an enhanced enjoyment of food’s sensory characteristics.” It’s difficult to quit eating once you start since everything you’re eating tastes delicious.”

The good news, he continues, is that THC has no long-term consequences after it exits the brain. “It doesn’t leave you with a strong want for more while you’re coming down from marijuana.”

The Short Term Effects of Marijuana Vary

Although everyone who smokes or eats cannabis experiences the same biological processes, how those processes make people feel differs greatly. “Some people are hypersensitive to THC, while others are not,” Gruber explains. “Some people become quite paranoid, while others have no such issues. Some individuals say things like, “Oh my God, I felt so hungry that I ate everything in the house,” while others never get hungry. Even if you’re smoking the same Granddaddy Purple, if someone throws you a bowl or a vape cartridge, you’ll probably have a different experience than they do.”

This might be due to a variety of factors. “So much relies on your past usage history, whether you’ve used THC or other things before,” Gruber explains. “It also relies on your own chemistry and metabolism, as well as the product itself, such as if it’s a cultivar with high levels of other cannabinoids that counteract THC’s effects.”

Another determinant is the level of activation of a person’s endocannabinoid system prior to using cannabis. “Let’s say 70% of your receptors are activated, but only 20% of that person’s receptors are triggered immediately before they take marijuana,” Piomelli explains. “As a result of this disparity, you may feel panicked after smoking, whilst the other individual feels more calm.” This also explains why, despite consuming the identical thing both times, the same person might have distinct affects.

Because there are so many unknown variables at play, Gruber recommends that anyone new to marijuana, as well as seasoned users trying out new products, “start low and go gradually” to observe how they react. “You can always add more,” she continues, “but you can never take it back.” “It’s impossible to exhale.”

Final Thoughts

Young users, whose brains are still building neural connections, have the largest long-term impacts from marijuana. The fact that most people who use marijuana also drink alcohol or other drugs, which can have their own detrimental effects on the brain, has impeded research into the effects of marijuana on the brain.

By Felix Wood

Many readers find issues about Marijuana, and they believe that it is a rich source of THC. They are also associate the Name with racism. Felix Wood understands all this clearly, and he writes informative content explaining why THC is like a hemp plant. Felix learned many things about herbal medicine. It is through his academics that he started developing an interest in CBD products. If you need real insights into Marijuana. Be sure to find all this from Felix's work. He has written many eBooks, articles, and magazines about marijuana. He even works in a CBD company that uses Marijuana to make CBD products. Felix enjoys doing exercises because he values fitness and wellness.

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