The Science of Marijuana

Now more than ever, the science of marijuana needs a blog post. With so many states legalizing marijuana, we ought to know the answers to questions like,  ‘how does marijuana affect your brain?’ And, ‘how does the endocannabinoid system work?

Heck, what is the endocannabinoid system? (ECS)

We better back it up and start at the beginning! Marijuana 101.


Which one of those plants above is Cannabis sativa? 


I did stick w a purple theme though!

Cannabis sativa, a plant known more commonly as marijuana, is popular due to its induced psychological & euphoric states when ingested or smoked.

Many states are joining the party & taking steps towards cannabis legalization, but federal law still prohibits its sale and consumption. Why?

What is the deal with marijuana?

the science of marijuana


If ancient Assyrian sources referring to the "hand of ghost" are considered credible, reports of cannabis use can been traced back to cuneiform tablets circa 2700 BC.
Mesopotamia & Marijuana
There are sources that suggest that chronic toothaches may have led the first President of the United States, George Washington, to grow the plant for medicinal purposes.
Queen Victoria is reported to have made use of an alcoholic extract of the cannabis plant, possibly to assist with pain of childbirth (Victoria had nine children between 1840 and 1857)
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‘Nine is a lot of children, George should have brushed more, & who can read those tablets, anyway?’



At the turn of the 20th century, cannabis was a little-used drug among Americans.
With the start of the Mexican Revolution in 1910, many Mexicans began moving to the US, & they brought the tradition of smoking marijuana along.
In the 1930s Harry J. Anslinger, head of the Federal Bureau of Narcotics, turned the battle against marijuana into an all-out war.
Hx of marijuana reference
Some believe that he was motivated less by safety concerns & more by a desire to promote his newly created department.
Whatever the impetus, Anslinger sought a federal ban on marijuana.
To this end, he initiated a high-profile campaign that relied heavily on racism.
Aided by an eager news media—and such propaganda films as Reefer Madness (1936)—Anslinger oversaw the passage of the Marihuana Tax Act in 1937, which made the drug illegal across the United States.
Watch Reefer Madness here
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That slide show was embarrassing to assemble & I had nothing to do with it!

At least I get to show off my manicure!


As I weeded through the plethora of scientific literature about the physiological & therapeutic effects of cannabis & cannabinoids, & deconstructed how the endocannabinoid system works, one fact stood out. (And yes, I am going to overuse puns)

I should be writing a book about cannabis, not a blog post.

A PubMed search for scientific journal articles published in the last 20 years containing the word “cannabis” revealed 22,771 results.

Use the word “cannabinoid,” and the results increase to 26,570 articles.

I ate chocolate & researched & gardened while I stalled to write this post. (hence the flowers above & my precipitous drop in website visitors)

Okay, I’ll stop whining & get to the science of marijuana & how the endocannabinoid system works. 

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The endocannabinoid system (ECS) has attracted more scientific attention due to its involvement in many different functional processes in the brain, including the regulation of emotions, motivation, & cognition.


The ECS is a complex physiologic network that helps establish & maintain overall health and wellness.
ECS overview
Initially, scientific findings suggested that the endocannabinoid system function was only connected to the brain and nerves
Further study revealed that
Endocannabinoids & their receptors are found throughout the body
Book chapter ECS
In each tissue, the endocannabinoid system performs different tasks
But the goal is always the same
Role of EC
Homeostasis is maintenance of a stable internal environment despite fluctuations in the external environment.
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The endocannabinoid system is not only present inside human bodies but, in all vertebrates, including mammals, reptiles, fish, amphibians, and birds. 

This does not include our favorite pollinators, bees.

How does the endocannabinoid system work-Louie

For the endocannabinoid system to function, it needs three components:

Inventively called:

Cannabinoid Receptor 1 (CB1) & Cannabinoid Receptor 2 (CB2).

Endocannabinoids are neurotransmitters our bodies naturally produce to stimulate CB1 & CB2 receptors.

The two most well-understood of these molecules are called anandamide & 2-arachidonoylglycerol.

The links above have about 100 articles about each molecule and how they regulate our bodies.

Not going here today.

Pictures of common backyard birds_Lessie
TQ for skipping enzymes

Even though the chart is not all that impressive,  cannabinoid receptors are spread throughout the body – attached to cellular membranes – and are possibly more numerous than any other connective system.




Anandamide has also been found in plants, including small amounts in chocolate!

Did I just say ‘PLANTS?’

What a perfect segue to the science of marijuana! Cannabis sativa is a plant!

Monarch on coneflower Susan Berk Koch

If you want to read how to raise monarchs, click here!


People–myself included interchange, ‘marijuana’ and ‘cannabis.’

For the record, cannabis is the botanical name for a genus of flowering plants. 

Marijuana refers to cannabis strains, or their dried leaves, or flowers, which contain THC. 

Back to the science of marijuana.

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CB1 receptors not only respond to our naturally-produced endocannabinoids, but CB1 receptors respond to the active compounds in Cannabis sativa. 

Remember from that uninspiring chart above that CB1 receptors are primarily in the brain & central nervous system. (CNS)

This includes the major psychoactive ingredient of cannabis: Delta-9 tetrahydrocannabinol (THC!)

Which would make what we’re talking about marijuana.


You now know that our cannabinoid receptors are activated by anandamide & 2-arachidonoylglycerol, the neurotransmitters & natural cannabinoids that our bodies produce.
And that the main psychoactive cannabinoid in the cannabis plant is THC
The CB1 receptor transduces signals in response to CNS-active constituents of Cannabis sativa.
Endocannabinoid Binding
IOW, THC mimics our natural endocannabinoids & binds to our cannabinoid receptors.
This occurs in in three main places in our brain.
The cerebellum, basal ganglia, & hippocampus are responsible for short-term memory, learning, problem-solving, & coordination.
Detailed neuroanatomical and electrophysiological analysis of mammalian nervous systems has revealed that the CB1 receptor is targeted to the presynaptic terminals of neurons where it acts to inhibit release of 'classical' neurotransmitters.
Cannabinoid receptor 1 (CB1) is critical in stress regulation and the development of mood disorders [anxiety, depression, bipolar disorder), in post-traumatic stress disorder (PTSD), as well as in the etiopathogenesis of schizophrenia, attention deficit hyperactivity disorder (ADHD), or eating disorders (i.e. anorexia and bulimia nervosa).
Just in case this is too easy to understand...
THC & another cannabinoid in cannabis sativa, CBD
...also interact with other receptors, transporters, enzymes, cellular structures, membranes, and ion channels.
THC & CBD ion channel study
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We’ve established that marijuana refers to the parts of the plant cannabis sativa that contain substantial amounts of THC. 

The cannabis plant contains about 540 chemical substances!

How does the endocannabinoid system work _CBD

540 compounds in cannabis are impressive. So are the 800 compounds in chocolate!

Louie bests Ian every time
Louie impresses everyone w his wrestling skills, too

Over 100 cannabinoids have been identified including THC & CBD. CBD or cannabidiol is the second most prevalent active ingredient in cannabis.

CBD is an essential component of medical marijuana
CBD is derived directly from the hemp plant, a cousin of marijuana, or manufactured in a laboratory.
Harvard Health_CBD
The mechanism of action of CBD in terms of its psychoactive & therapeutic effects is not fully clear.
Meaning scientists aren't sure how CBD works.
I dug around for hours trying to find the mechanism of action for CBD.
I had to let it go.
CBD has been touted for the treatment of many ailments for which it has not been studied. In those diseases with evaluable human data, it generally has weak or very weak evidence of efficacy.
There is a notable exception!
The strongest scientific evidence is for its effectiveness in treating some of the cruelest childhood epilepsy syndromes, such as Dravet syndrome and Lennox-Gastaut syndrome (LGS), which typically don’t respond to antiseizure medications.
CBD & seizures
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In January 2022, when analyzing over-the-counter cannabidiol (CBD) products, here’s what the Journal Of Epilepsy and Behavior found:


Cannabinoids are considered to have fewer & milder side effects than many pharmaceutical drugs they may be able to replace.

Don’t make the mistake, though, of thinking that “natural” products are side-effect free.

Proper mask placement and eyewear

Currently, the FDA does not guarantee the safety, effectiveness, or quality of OTC CBD products. If you’re interested, here’s a 2022 article from Healthline that talks about several over-the-counter CBD oils w/ a brief tutorial on reading labels. 

Aside from the epilepsy syndromes above, have cannabis or cannabinoids been proven helpful in treating other health conditions?

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Research is ongoing.
Drugs containing cannabinoids may be helpful in treating the rare forms of epilepsy I mentioned, nausea & vomiting associated with cancer chemotherapy, & loss of appetite and weight loss associated with HIV/AIDS.
In addition, some evidence suggests modest benefits of cannabis or cannabinoids for chronic pain and multiple sclerosis symptoms.
Heck, I use China Gel for sore muscles when someone else may find it useless.
Research on cannabis or cannabinoids for other conditions is in its early stages.
NIH link
Cannabis is not helpful for glaucoma.
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A growing body of literature suggests that cannabis intake can induce memory loss in humans and animals.
Cannabis effects on cognition mostly results from the ability of its main psychoactive component, delta9-tetrahydrocannabinol (THC), to activate type-1 cannabinoid (CB1) receptors in the brain, thus interfering with the action of endocannabinoids
Click Here
This causes cortical inflammation, resulting in long term cognitive impairment
Besides the recreational use, daily cannabis users may also belong to the ever-increasing population of patients who are administered cannabis as a medicine.
Memory loss side effect
Brain CB1 receptors are essentially blunted in cannabis users
brain blunted
Several studies have shown that long-term and heavy cannabis use during adolescence can impair brain maturation and predispose to neurodevelopmental disorders
Cannabis study
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At least adult brains recover the cognitive impairments after a period of abstinence.

However, adolescent brains sustain permanent damage!  That is a sobering side effect of THC & a bad answer to the question, ‘how does marijuana affect your brain?’

And we’re tiptoeing around the efficacy of CBD products & medical marijuana now. 

If that’s the case, why are so many states legalizing marijuana?

Dangerous ground!

Don’t walk away, let’s have a look.

Don't get left behind__Make Sense of Science_Alex


The legalization of weed has been a hot topic for consumers and lawmakers alike. The debate ignited when, in 2012 Colorado & Washington became the 1st states to legalize recreational use of cannabis.
CO & cannabis
Many states are joining the party & taking steps towards cannabis legalization.
Pun intended!
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As of May 2022, my state, Wisconsin is a holdout. Nothing is legal here.

Color me cynical but one reason states are jumping on the cannabis train could be tax revenue.

What are so many states legalizing marijuana_CASH
A chart follows w/ 2021 tax revenue for several states
The states are raking in money but
...many people, even in states with legal recreational weed use, still rely on the illegal market.
This may be because legal cannabis is expensive.
high taxes for one thing!
One reason the cost is so high?
Marijuana is not legal under federal law, so cannabis businesses cannot deduct expenses on their taxes.
But if you impose a high enough tax on anything, you run the risk of driving it underground.
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Federal law still prohibits the sale & consumption of marijuana.

Why is marijuana illegal under federal law?

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The laws are difficult to weed through.
Joking aside, marijuana is a Schedule I Drug
Schedule I Drugs
are defined as drugs with no current medical use with high potential for abuse and/or addiction.
Until marijuana is rescheduled, large scale research will probably not occur.
How do scientists & the marijuana lobby prove that it should not be a Schedule I?
Research, right?
One big issue is that we’re talking about a highly impure substance.
Those 540 compounds!
Since cannabis is a naturally occurring substance, it can’t be patented so research is dicey.
This bring us to synthetic aka manmade cannabinoids.
Synthetic cannabinoids are one of the most rapidly expanding classes of novel psychoactive substances found in illegal markets.
These substances have evolved to the point that many examples no longer fit with the traditional cannabinoid classification system, leading to inconsistencies in regard to their chemical structures.
Synthetic cannabinoids
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My slide show went off on a tangent. Essentially, for marijuana to be removed from its Schedule I Classification:

The FDA requires large studies, including hundreds of participants, that evaluate both the effectiveness & the safety of those drugs for the specific group of people it’ll be used for.

That’s a long, expensive, & arduous process.

A Pew research poll shows where U.S. opinions fall as of April 2021.

Do opinions matter?


What is your opinion about legalizing marijuana? Have you used cannabinoids aka CBD to help w/what ails you? Noticed any side effects? 

Learn anything new from my post?




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July 25, 2022 6:45 am

This was really interesting. I’ve used edibles a few different times and had mixed results. If I knew marijuana would give me less side effects than my psych meds I would do that instead. But I want to see more research. The memory loss is definitely hard to overlook. Im not morally against legalizing it. That’s just for my personal usage.

July 25, 2022 7:01 am

Wow, I didn’t know that our bodies manufacture endocannabinoids, but it makes sense. I think adults should be able to use marijuana the same way they can drink alcohol, but keep it out of the hands of teenagers. Thanks so much for this article! Amazingly well researched.

Unwanted Life
July 25, 2022 7:02 am

I’m pro drug decriminalisation in all forms, to make it safer, reduce crime, and so people can get the help they need without fear of stigma. I believe that even though I suffered from drug induced psychosis

July 25, 2022 7:09 am

Your flowers are gorgeous and so is this article. Chock full of information yet not dull or didactic. People are going to smoke, but it screws up kids so it may be better if it was legal federally, to better keep it out of the hands of minors. I learned a ton, thank you.

July 25, 2022 8:15 am

Your point about just because something is natural doesn’t make it safe – think of mushrooms, for example. It’s interesting that there are so many CBD products on the market (not that I’ve ever tried any) and this was a really in depth, useful article, thank you, Sue 🙂

Jordanne || ofaglasgowgirl
Jordanne || ofaglasgowgirl
July 25, 2022 11:15 am

What an in-depth post. I’m blown away by the amount of time and research you’ve put into this and have learnt a whole lot! I had no idea we naturally produce endocannabinoid!

I would love there to be a day where it’s decriminalised and legal all over the world, just because I’ve known people who use it to manage their MS/cancer side effects and seeing the benefits of helping those people really did turn my mind around on it.

I do however think there needs to be so much more research into it and using it for medical conditions, especially reading about the cognitive impairments. I do believe though that adults should be able to make their own choice about it though, especially when the likes of Alcohol and Cigarettes are legal.

July 25, 2022 3:09 pm

Excellent job as usual. I have trouble with legalizing something that we know can harm our bodies to the extent that you described in the podcast. I do support the medicinal purposes for marijuana. I have used CBD oil for arthritis pain and it does help me. Thanks for the great discussion. One question, why does it cause the munchies? Mike

Thrift Plan Enjoy
Thrift Plan Enjoy
July 25, 2022 5:25 pm

Great post. So informative. Here in the UK it’s still illegal and I’m glad. It sounds a bit risky to be trusted.

July 25, 2022 5:36 pm

This was an interesting post. I enjoyed the way you presented your information and shared stats. I think it should be legalised to make it safer and more regulated. More research is definitely needed though, esp about memory loss. I think like alcohol, which in my opinion is way worse, should be restricted to consenting adults. Let’s allow our kids brain to mature before they indulge in any substances.

Jeannie M | Absolutely Enchantinq
Jeannie M | Absolutely Enchantinq
July 26, 2022 6:53 am

In my opinion, I don’t think it should have been illegal in the first place. I think all they had to do was study it if they wanted to, present the facts to the pleople and then work to regulate, not stop it. This was very interesting to read.

July 26, 2022 11:57 am

I do not know much about marijuana. Let alone the scientific facts from it. So this was an extremely interesting and informative post. Thanks so much for sharing all about it!

Jaya Avendel
July 26, 2022 3:21 pm

I quite enjoyed reading this post, especially with your fun graphics and slides! Your thoughts on how you should be writing a book stood out to me, but I think you have packed in enough information to make this a worthy read.

I have friends who smoke and eat edibles, and I know it works for what they use it for, so that seems like a good thing in my eyes. 🙂

Sarah Collins
Sarah Collins
July 26, 2022 3:27 pm

What an interesting post, incredibly well researched, I learnt loads.
I was in America a couple of months ago, I didn’t know it had been legalised in some states but cottoned on fairly quickly….I too am cynical suspect being able to tax it plays a big part.
It’s not something I use or have any interest in using but not against legalisation, and think there should be research into how it can help with medical conditions

Amy Laundrie
July 26, 2022 5:39 pm

Since it’s been proven that adolescent brains sustain permanent damage with marijuana use, I believe it’s wrong to legalize it and it’s shameful that states put tax revenue before the health of people.

Mummy Conquering Anxiety
Mummy Conquering Anxiety
July 26, 2022 7:28 pm

A great, balanced argument. All backed up by science. Thank you for sharing.

July 26, 2022 7:45 pm

I definitely agree that taxation is a major motivator to legalize marijuana. Here in Canada, the government has opened its own sales to people both online and at brick-and-mortar stores. You can imagine how this could have an impact on the flow of finances. I’m sure the states that haven’t legalized it can see things like that and are realizing the potential.

July 27, 2022 2:14 am

This is such an interesting read! Cannabis is illegal in the U.K. but there have been cases where people have challenged courts for medical needs but have failed.

Jenny in Neverland
July 27, 2022 6:10 am

I won’t lie, science goes straight over my head. I was never any good at it in school and couldn’t grasp the concepts and nothing has changed now as an adult, so a lot of this did go over my head but I think it’s great that you’ve provided such a lengthy informative post about this subject!

Carolyn Holton
Carolyn Holton
July 28, 2022 6:34 pm

Interesting and informative post! I have friends who use it for anxiety and sleep disorders, and I have no problem with the legalization. The memory loss is a big concern, though.

February 24, 2023 10:32 pm

I agree with your point of view, your article has given me a lot of help and benefited me a lot. Thanks. Hope you continue to write such excellent articles.

Susan Berk Koch author

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