Cannabis and Diabetes: What You Need to Know


Editor’s Note: Beyond Type 1 in no way encourages illegal activity. Marijuana possession and usage continue to be an offense under United States federal law and in many countries. Information contained within this article is meant to keep people with diabetes who choose to partake safe and well. 

Cannabis comes from the plant Cannabis sativa, which contains the chemical THC—well-known for its effects on your mental state. Known by many other names—including marijuana, weed, pot, flower, grass, etc.—it can be consumed via smoking, vaping and in edible forms. Today, it can be cultivated to contain more THC, increasing the potency of its mind-altering effects.

For the purposes of this resource, we’ll discuss what you need to know as a person with diabetes if you choose to consume products that contain THC.

What’s the law?

In the U.S., 21 states and Washington D.C. have legalized marijuana (containing tetrahydrocannabinol, also known as THC) for those over the age of 21. An additional 18 states have legalized medical marijuana, which requires medical approval by a registered healthcare provider. Find out where it’s legal in the U.S. and around the world.

Marijuana use remains completely illegal in 11 states: Idaho, Wyoming, Nebraska, Kansas, Texas, Wisconsin, Indiana, Kentucky, Tennessee, South Carolina and North Carolina.

Marijuana possession and use also remain a federal offense; the law applies to offenses committed on federal property, i.e. national parks, military property, and any other land, landmarks or buildings under federal control. Flying or otherwise traveling between states while in the possession of marijuana is also unwise.

The THC in marijuana is different from cannabidiol (CBD), which is another chemical found in the same plant. CBD is not mind-altering and research is currently being done on its potential positive impacts on inflammation, pain, sleep, etc. in some individuals.

CBD can be isolated from cannabis plants and is often added to food, drinks, beauty products and other over-the-counter products that are not officially approved or screened by the Food and Drug Administration (FDA).

How does marijuana impact your brain and body?

The cannabis plant can be grown to contain higher amounts of THC, which increases the effect it can have on both your mental and physical state. Marijuana alters your brain chemicals and influences how your brain receptors communicate with your body.

This is one of the reasons why, even in states with legalized weed, the minimum age for recreational use is 21-years-old. Until the age of around 25, our brains are not fully developed. Adding a mind-altering chemical to a brain that is still developing poses more immediate and long-term risks.

Medical usage may be approved for those under the age of 21 but must be done with strict medical approval and supervision. Whether recreational or medicinal, anyone who chooses to use marijuana should ensure they are in a safe environment with safe people, since THC can impact the brain and body in myriad ways.

The way your brain and body react to marijuana can vary drastically from one experience to another based on a variety of variables, including:

  • The strain (type) of marijuana
  • The amount you consume
  • How you consumed it (smoking, vaping, eating, drinking, etc.)
  • Your mental state at the time of consumption
  • Other substances or medications in your system at the same time, including how much insulin is in your system from basal (background) insulin or a recent bolus (given for higher blood sugar or carbohydrates)

The effects of marijuana can also vary considerably from person to person. Do not assume your body will react the way another person’s reacted. How marijuana makes you feel will vary considerably based on your own body’s chemical makeup. In the hours after consuming marijuana, you could feel…

  • Relaxed, mellow, calm
  • Euphoric, happy, creative
  • Sleepy, lazy, like your body is heavy
  • Shaky or on edge, similar to the feeling of a low blood sugar
  • Talkative, with wandering thoughts
  • Quiet, with mental chatter muted
  • Anxious, paranoid, without the ability to calm yourself
  • Thirsty, hungry, unable to control appetite
  • Nauseated, dizzy

Additionally, marijuana stays in the system for three to 30 days, depending on the type and frequency of use. This means you may test positive in a drug test for up to a month after use. It also means that brain chemical changes as a result of consuming marijuana can also last from three days up to a month after consumption. In the days and weeks following use, some people report feeling generally relaxed and calmer, while some report feeling heightened anxiety or brain fog.

Research is being conducted on how CBD and THC impact and possibly work with the human endocannabinoid system (ECS)—a system in the body that aids in the regulation and balance of key bodily functions like energy balance, appetite, pain, mood and memory.

Different ways of consuming marijuana

Marijuana’s impact on your system can change depending on the method of consumption and how much is consumed. Marijuana may be…

Inhaled: When smoked or vaporized, the impacts of marijuana on the brain and body are more immediate, kicking in quickly and reaching a peak impact within the following few minutes to an hour.

Inhaled marijuana tends to have a more immediate impact on blood sugar levels—some people report that their blood sugar levels start to drop almost immediately after consumption. The effect can last hours with “brain fog” that can stay in the system for up to three days. Intensity will vary based on delivery method, amount consumed and strength of the marijuana strain.

Know that smoking anything can be harmful to your lungs because of the many chemicals you are inhaling in the process.

Eaten: Marijuana can be cooked with a fat source like butter or oil so the THC is absorbed into the fat source, then added to food, candy, or drinks. When eaten, the effects of marijuana are delayed and can be more intense. Peak impact will happen within thirty minutes to an hour after consumption and typically last longer than when inhaled. Expect to feel high for about two to eight hours after consumption.

Variables that affect the duration of your high can include the edible type (brownies vs. gummies, for example), the strain of marijuana, how much you consumed and your metabolism. If you choose to partake, start very slowly and pay attention to the dosage.

Edibles bought from an official dispensary should always be labeled with the amount of marijuana in each edible serving size (usually 10 mg per serving), but edibles made outside of a sanctioned dispensary can vary widely in strength.

And of course—remember to dose insulin for carbs in the edible. It’s still food! Just know that, for some people, marijuana can make you more sensitive to insulin, so you may need less than usual.

What should people with diabetes expect when they consume marijuana?

Marijuana impacts mental function, which—when managing a complex chronic illness where repercussions can be immediate—must be planned for and paid close attention to. If you are consuming marijuana for the first time here are some important guidelines to consider:

  • Don’t do so alone. Make sure you are with someone you trust who knows that you have diabetes, knows how to recognize the signs of low and high blood sugar and pledges to remain sober enough to help you if needed.
  • Know your starting blood sugar and how much insulin you have on board. Marijuana makes some people more sensitive to insulin and can make a low or high blood sugar feel more severe. The sensations that come with consuming marijuana can sometimes feel similar to low blood sugar. Monitor your blood sugar regularly, either with a continuous glucose monitor (CGM) or frequent blood sugar checks via a meter. Have fast-acting glucose and glucagon on hand in case of low blood sugar. Ensure those you are with know what to do in the event of a severe low.
  • Start slow. Marijuana impacts every person differently and different strains will impact you differently as well. Start very slowly, get to know how marijuana impacts your system, and don’t assume that just because you’ve tried it once or a few times, it will always affect you in the same way.

What people in the diabetes community want you to know:

Apart from the basic considerations already mentioned, here are some additional pointers to keep in mind, as recommended by the diabetes community:

Be aware of altered perception

Like alcohol, if you’re under the influence of a mind-altering substance, you may not be able to recognize if you’re feeling “low” or “high” in terms of your blood glucose levels. Know that your general perception may be inaccurate or faulty.

“I thought I was dying. I was convinced I needed an ambulance. I ate like three McChickens without bolusing and woke up at 450 mg/dL.”

“I’m lucky to have a CGM, so I always watch my blood sugar closely when I’m high. On two separate occasions, I was around 150 mg/dL and moving down slightly, but I felt really low—shaky, vision blurring, like I was about to pass out. The first time I was able to stay conscious but the second time I did pass out and hit the ground pretty hard. Once I came to a few seconds later—even though I only had a unit of insulin on board—my blood sugar was falling FAST. I ended up having to drink an entire carton of juice because I ended up around 70 mg/dL with double down arrows. It seems to only happen when I smoke a little too much. It’s weird though, that my body will act like I’m SUPER low even though I’m not. It wasn’t just feeling low; my body acted like I was that low.”

Check your blood sugar levels frequently

Because of altered perception, you should check your blood sugar at regular intervals to be sure you’re in a safe range, and ensure you’re with people who know how to help if you experience extremely high or low blood sugars while high.

“Smoking always makes my blood sugar go low naturally. I start smoking and then it just slowly creeps down, so I always have to be careful to either suspend my pump or have some sugar.”

“I am always so scared to crash low after drinking that I never really have fun because I get so worried… There is no sugar or carbs in smoke, so you don’t get that effect of going really high, then crashing back down later… I prefer smoking to drinking because I actually feel safer and more in control of my type 1 diabetes (T1D).”

Dose insulin—and do it carefully—for “munchies”

Because hunger can be a side effect of marijuana, you may want to eat a lot, so be sure to give yourself insulin for exactly what you plan to consume. Because your mental state will be altered when you’re high, it may make sense to make a plan beforehand—get your snacks ready and write down their carb count and the corresponding insulin dose for them on a sticky note or in your phone. Or, conversely, don’t keep high-carb munchies in the place where you’re going to consume weed—apples, carrots, etc. may work well instead.

“When I smoke my blood glucose (BG) ends up going high because I get the munchies and eat everything.”

“I get what I like to call the “gradual munchies.” I just sort of slowly snack on everything over a long period of time, and since I never eat more than a handful of something at once I never properly carb count or do the right amount of insulin. My BG always ends up going high.”

Tell your healthcare provider

We know, this one feels scary. But your healthcare provider—especially the one or team you go to for your diabetes care, can help you make a plan for when you consume marijuana. They can help you identify blood sugar patterns around consumption and come up with a plan for dosing insulin when you have THC on board, as your body may vary in its insulin sensitivity.

“I always feel like I’m going to get “in trouble” with my endo, but she’s actually been non-judgemental and is just here to help me from a medical perspective. Does she prefer I smoke? No. But she helps me with a plan to keep me safe when I do.”

The bottom line

As with using any substance, be aware of your surroundings and your body. Take extra precautions to stay safe and capable of successfully managing your diabetes. And remember, don’t feel pressured to try something that you don’t feel comfortable trying. The decision is up to you, and you alone.

WRITTEN BY BT1 Editorial Team, POSTED 04/14/22, UPDATED 02/22/23

This piece was authored collaboratively by the Beyond Type 1 Editorial Team.