GLP-1 and Cannabis: What the Research Says About Weed on Ozempic

If you use cannabis and you're on a GLP-1 medication, you're probably wondering: does weed mess with Ozempic? Can you still smoke on Wegovy? Will it make side effects worse?

These questions are showing up everywhere — Reddit threads, TikTok videos, and doctor visits. The short answer: there still isn't a clinical trial that directly tests cannabis alongside GLP-1 medications. But since our last update, several important studies have changed what we know about how these two substances interact in the body.

Here's what's new and what hasn't changed.

What's New: Key Research Updates (2025–2026)

The research landscape has shifted meaningfully since mid-2025. Here are the developments that matter most:

Semaglutide Linked to Reduced Cannabis Use Disorder

The biggest new finding comes from a large retrospective cohort study by Wang et al. (2024), published in Molecular Psychiatry. Researchers analyzed health records from 85,223 patients with obesity and 596,045 patients with type 2 diabetes, comparing those prescribed semaglutide against those on non-GLP-1 anti-obesity or antidiabetes medications.

The results: semaglutide was associated with significant reductions in both the incidence and recurrence of cannabis use disorder (CUD) in both the obesity and T2DM populations over a 12-month follow-up period.

This is an observational study — it shows association, not causation. It cannot prove that semaglutide directly reduces cannabis use. The populations studied all had metabolic conditions, and the study did not control for dosing, adherence, or length of semaglutide use. But the signal is consistent with broader research showing GLP-1 receptor agonists may reduce reward-seeking behavior across multiple substances, including alcohol and nicotine.

Cannabis Lowers Blood GLP-1 Levels

A double-blind, placebo-controlled trial found that cannabis — whether smoked, vaporized, or taken orally — reduces blood GLP-1 concentrations in regular cannabis users compared with placebo. This finding, highlighted in a 2026 narrative review by Caplin and Fraser in the Canadian Journal of Addiction, suggests a reciprocal relationship: cannabis use suppresses the body's natural GLP-1 signaling.

This mirrors findings with other substances. A similar study found that cocaine also reduces endogenous GLP-1 levels. The clinical significance is still unclear — does lower GLP-1 from cannabis use mean your GLP-1 medication is working harder to compensate? Or does it simply reflect how the endocannabinoid and GLP-1 systems communicate? Nobody can say yet, but it's an active area of investigation.

Growing Evidence That GLP-1 Agonists May Reduce Substance Use

Multiple 2025–2026 reviews now cover GLP-1 receptor agonists and substance use disorders together:

Yammine et al. (2025) in Current Addiction Reports reviewed clinical and epidemiological evidence, noting that large-scale retrospective studies consistently support improvements in substance use–related outcomes with GLP-1RA treatment, while RCT data remain mixed.
Srinivasan, Farokhnia et al. (2025) published an endocrinology primer in the Journal of the Endocrine Society covering GLP-1 therapeutics and their emerging role in alcohol and substance use disorders, including a section on the cannabis–GLP-1 link.
Caplin and Fraser (2026) in the Canadian Journal of Addiction conducted a narrative review identifying only one published clinical study on GLP-1RAs and cannabis (the Wang et al. cohort study), and no RCTs — highlighting how early this research still is.

The pattern across substances is consistent: GLP-1 agonists appear to dampen reward-seeking circuits in the brain. For cannabis specifically, the evidence is still thin — mostly observational. No randomized controlled trial has tested a GLP-1RA for cannabis use disorder in humans.

What We Know So Far

There is still no published clinical trial that specifically tests cannabis use alongside GLP-1 medications like semaglutide (Ozempic, Wegovy) or tirzepatide (Mounjaro, Zepbound). That means nobody can say for certain whether cannabis makes GLP-1 drugs more or less effective, or whether combining them creates risks that either drug alone would not.

What we do have now:

A growing body of evidence that GLP-1 agonists may reduce substance-seeking behavior, including for cannabis
A clinical finding that cannabis lowers natural GLP-1 levels in the blood
Research on how each substance affects the body on its own
Reports from people who use both and share their experiences online
Medical guidance based on how the two systems overlap

How GLP-1 Medications and Cannabis Affect the Body

Both GLP-1 medications and cannabis act on systems related to appetite and digestion. They just do it in different ways.

GLP-1 medications (semaglutide, tirzepatide):

Slow stomach emptying
Reduce appetite
Can cause nausea, constipation, and stomach discomfort
Help regulate blood sugar
May modulate reward circuitry in the brain (emerging evidence)

Cannabis (THC and CBD):

Stimulates appetite in many people (the "munchies")
Can reduce nausea for some people
May slow digestion
Affects mood, alertness, and reaction time
Reduces blood GLP-1 levels (new finding)

The most obvious tension: GLP-1 medications try to reduce your appetite. Cannabis often increases it. But the real-world picture is more complicated than that — and new research suggests the relationship goes in both directions.

Does Weed Affect GLP-1 Effectiveness?

There is no evidence that cannabis stops GLP-1 medications from working. But there are several things to think about:

Appetite Conflict

If cannabis makes you hungrier and you eat more — especially high-calorie foods — that can work against the appetite-suppressing effect of your GLP-1 medication. You may not lose weight as effectively, or you may struggle more with portion control on days you use cannabis.

Not everyone gets the munchies. Some people on GLP-1s report that cannabis does not increase their appetite the way it used to, because the GLP-1 is already doing a strong job of suppressing hunger signals. And if the emerging research on GLP-1 agonists and reduced substance use holds up, it's possible that GLP-1 medications may dampen the drive to use cannabis in the first place for some people — though this remains unproven.

Blood Sugar

Cannabis can affect blood sugar. Some studies suggest THC may slightly raise blood sugar in the short term. GLP-1 medications lower blood sugar. If you have diabetes and are monitoring glucose closely, this interaction is worth discussing with your endocrinologist.

The GLP-1 Level Connection

The recent finding that cannabis reduces blood GLP-1 concentrations adds a new layer. If your body is producing less GLP-1 because of cannabis use, your GLP-1 medication may be compensating for a larger deficit than it would otherwise. Whether this has any practical effect on treatment outcomes is unknown — but it suggests the two substances are not as independent of each other as previously thought.

Absorption

There is no known mechanism by which cannabis would change how your body absorbs semaglutide or tirzepatide. The drugs are injected (or taken as a pill in the case of Rybelsus), and their absorption does not depend on the digestive system in the same way an oral drug would.

Side Effects When Combining Cannabis and GLP-1s

This is where the overlap gets real. Both can cause:

Nausea

GLP-1 medications cause nausea in many users. Cannabis can either help or worsen nausea depending on the person, the dose, and the strain.

Some people find that small amounts of cannabis ease GLP-1 nausea. Others say it makes the nausea feel worse or more disorienting.

For help managing GLP-1 nausea, see our Nausea Triggers and Management guide.

Dizziness and Brain Fog

Both substances can cause dizziness, lightheadedness, or brain fog on their own. Together, these effects can stack. If you're already feeling foggy or dizzy from your GLP-1 medication, adding cannabis may make those symptoms stronger.

Dry Mouth

GLP-1s can cause dry mouth indirectly (through dehydration from reduced eating and drinking). Cannabis is well known for causing dry mouth. Combined, you may notice your mouth feels very dry — which can also worsen sulfur burps and overall comfort.

GI Changes

Both can slow digestion. If your stomach is already moving slowly because of your GLP-1, adding cannabis might make bloating, fullness, and constipation worse.

Increased Heart Rate

THC can temporarily raise heart rate. GLP-1 medications can also cause a small increase in resting heart rate in some people. If you have a heart condition, this combination is worth raising with your cardiologist.

What About CBD?

CBD (cannabidiol) is different from THC. It does not cause a high, and it does not typically stimulate appetite the way THC does.

Some early research suggests CBD may have anti-inflammatory and anti-nausea properties. But there is still no strong evidence about how CBD interacts specifically with GLP-1 medications.

If you are using CBD for symptom relief (pain, anxiety, sleep), the risk of interaction is likely lower than with THC-containing products. But CBD can affect how your liver processes certain medications. A 2025 comprehensive review of GLP-1RA drug–drug interactions by Min et al. (published in Drug Design, Development and Therapy) highlighted that GLP-1 agonists have relatively few clinically significant pharmacokinetic interactions compared with many other drug classes — but CBD's effect on liver enzymes (particularly CYP3A4 and CYP2C19) means you should still check with your doctor or pharmacist if you are taking other medications alongside your GLP-1.

For more on drug interactions with GLP-1s, see GLP-1 Drug Interactions.

What Reddit and Social Media Users Report

Online discussions about combining cannabis and GLP-1s are mixed:

Some people say cannabis helps them eat when GLP-1 nausea makes food unappealing
Others say the munchies undermine their progress and they struggle with overeating
A number of users report that the combination makes them feel "off" — more dizzy or foggy than either substance alone
Several people mention that GLP-1s reduce the munchies they used to get from cannabis
Newer reports describe some users noticing reduced desire to use cannabis after starting a GLP-1 medication — consistent with the Wang et al. cohort findings

These are individual reports, not scientific data. But they paint a picture of highly variable individual responses. What works for one person may not work for you.

For more on how real-world experiences compare to clinical trial data, see our GLP-1 Side Effects from Social Media Reports guide.

Practical Advice If You Use Both

If you use cannabis and are on a GLP-1 medication, here are some practical things to consider:

1. Talk to Your Doctor

This is the most important one. Your prescriber needs to know you use cannabis. Not so they can judge you — so they can give you the best care. Doctors are increasingly familiar with cannabis use and most will not be surprised.

2. Watch for Stacked Side Effects

Pay attention to how you feel when using both. If nausea, dizziness, or brain fog get worse on days you use cannabis, that is useful information.

3. Track Your Appetite

If cannabis triggers eating that goes against your goals, notice that pattern. Some people find that using cannabis only in the evening, or pairing it with planned meals, helps keep things in balance.

4. Stay Hydrated

Both substances can dehydrate you. Drink water regularly, especially if you are experiencing dry mouth. Adding electrolyte powder to at least one glass helps replenish what you lose. For hydration tips, see our hydration guide.

5. Be Careful with Edibles

Edibles can be hard to dose. If your stomach is already slow from GLP-1 medication, edibles may take longer to kick in and last longer than expected. This makes it easier to accidentally take too much.

6. Avoid Driving

Both GLP-1 medications (through dizziness or fatigue) and cannabis can impair your alertness. Do not drive if you are feeling impaired from either one — and especially not from both.

7. Pay Attention to Changes in Cannabis Use

If you notice your desire to use cannabis shifting after starting a GLP-1 medication, you're not alone. Social media reports and the Wang et al. cohort study both suggest this can happen. If you're trying to reduce cannabis use, this may be helpful — but if you're using cannabis medically, talk to your provider about adjusting your approach.

Regulatory and Legal Context

Cannabis laws continue to evolve. As of mid-2026, recreational cannabis is legal for adults in 24 US states plus Washington, D.C., and medical cannabis programs exist in most remaining states. The federal landscape has not changed significantly — cannabis remains a Schedule I substance under US federal law, though enforcement priorities have shifted.

This legal status has practical implications for GLP-1 users: because cannabis is federally illegal in the US, your doctor may face limitations in formally recommending it, and your insurance will not cover it. If you travel internationally, cannabis laws vary dramatically — a medical card from one state or country may not protect you in another.

Always follow your local regulations. What's legal where you live may not be legal where you're going.

The Bottom Line

The research picture for cannabis and GLP-1 medications is more nuanced now than it was a year ago, but the core uncertainty remains: there is still no clinical trial testing cannabis use alongside GLP-1 medications.

What's changed:

A large observational study found semaglutide associated with reduced cannabis use disorder
Cannabis has been shown to lower natural GLP-1 levels in the blood
Multiple 2025–2026 reviews confirm GLP-1 agonists as a promising but unproven area for substance use treatment

What hasn't changed:

Both substances affect appetite and digestion
Side effects can stack (nausea, dizziness, dry mouth, slowed digestion)
Cannabis may work against the appetite suppression that GLP-1s provide
Individual responses vary a lot
No direct drug–drug interaction has been identified

If you use both, talk to your doctor. Track how you feel. Be honest with yourself about whether cannabis is helping or hurting your progress. And stay tuned — this research area is moving fast.

This article is for informational purposes only and does not constitute medical advice. Cannabis laws vary by location. Always follow local regulations and consult your healthcare provider about substance use alongside prescription medications.