# GLP-1 Drugs and Quitting Smoking: What the Trials Actually Tested

By Ruth Calder, Enforcement Editor (https://glpwatchdog.org/authors/ruth-calder) | Published: 2026-08-21 | Updated: 2026-10-27

Canonical page: https://glpwatchdog.org/research/glp1-and-quitting-smoking

> The largest randomized trial found a GLP-1 added nothing to quit rates (63% against 65% on placebo) while holding post-cessation weight for as long as it was taken. A year later that advantage had gone too.

## Key points

- Dulaglutide added to varenicline: 63% quit vs 65% on placebo. At one year, 32% in both groups.
- It did prevent post-cessation weight gain (−1.0 kg vs +1.9 kg), but only while it was being taken.
- By week 52 the weight difference was 0.35 kg, with an interval spanning zero.
- The headline semaglutide study counted health care encounters and had no data on current smoking.

A GLP-1 does not appear to help you stop smoking. The largest randomized test of the idea gave 255 smokers either dulaglutide or placebo on top of varenicline and counseling, and after twelve weeks 63% of the drug group and 65% of the placebo group had quit, a difference of −1.9% that amounts to nothing.[1] What the drug did do was hold the weight: down 1.0 kg while the placebo group went up 1.9 kg. That is a real effect, and it is the one worth understanding, because a year later it had gone too.[2]

## What the trial actually tested

The trial ran at the University Hospital Basel between 2017 and 2020. Everyone in it was a smoker with at least moderate cigarette dependence who wanted to quit, and everyone got the standard of care: varenicline at 2 mg a day plus behavioral counseling. The randomization decided only whether a weekly injection of dulaglutide 1.5 mg or a weekly injection of placebo was added on top for twelve weeks.[1]

That design matters when you read the result. The trial asked whether a GLP-1 adds anything to treatment that already works, not whether it beats nothing, and that is the question a person already being helped to quit would ask. The answer was no.

*Basel trial, dulaglutide 1.5 mg weekly for 12 weeks added to varenicline and counseling (n = 255).*

| Outcome at 12 weeks | Dulaglutide | Placebo | Difference |
| --- | --- | --- | --- |
| Biochemically confirmed abstinence | 63% (80/127) | 65% (83/128) | −1.9% (p = 0.859) |
| Weight change | −1.0 kg | +1.9 kg | −2.9 kg (p < 0.001) |
| HbA1c | declined | — | −0.25% between groups |
| Gastrointestinal side effects | 90% (114/127) | 81% (81/128) | — |

Craving was measured directly, and it fell during treatment in both groups with no difference between them.[1] That matters, because the reason anyone expected this to work was a craving mechanism: the idea that GLP-1 signaling dampens reward in a way that would reach nicotine as well as food. In this trial, it did not show up in what the participants reported.

## The weight benefit did not survive the year

The same team followed the same participants to 24 and 52 weeks, and that follow-up is the part almost nobody quotes. Abstinence at one year was 32% in both groups.[2] The weight advantage narrowed to −1.0 kg by week 24 and to −0.35 kg by week 52, with a confidence interval spanning zero. Both groups had gained weight from baseline by then.

> The injections stopped at week 12. The weight came back over the following forty weeks. That is the same pattern GLP-1 trials show for weight loss generally, and it is the reason the trial’s own authors concluded that a future study should treat for longer, not that this one had found a short-term win.[2]

So the trade-off is this: the drug holds post-cessation weight for as long as you are taking it, and does not help you quit at any point. Whether that is worth an injection is a different question from the one the headlines answered, and it is yours and your prescriber’s. For how much weight quitting usually adds, and why switching to a vape does not prevent it, see [does vaping or nicotine cause weight loss](https://glpwatchdog.org/research/does-vaping-or-nicotine-cause-weight-loss).

## The smaller trial that pointed the other way

There is a second randomized trial, and it is more encouraging. Eighty-four prediabetic or overweight smokers were randomized to weekly exenatide 2 mg or placebo, all of them on a 21 mg nicotine patch with brief counseling, for six weeks. Abstinence was 46.3% on exenatide against 26.8% on placebo, a risk ratio of 1.70. Post-cessation body weight was 5.6 pounds lower in the exenatide group.[3]

Read the interval before the ratio. The 95% credible interval on that 1.70 ran from 0.96 to 3.27, which includes the possibility of no benefit at all. The paper calls itself a pilot, it enrolled a quarter as many people as the Basel trial, it ran for half as long, and it selected for smokers who were already prediabetic or overweight. Those are the conditions under which a promising number most often fails to repeat.

*The two randomized trials are not testing the same thing.*

|   | Basel (dulaglutide) | Houston pilot (exenatide) |
| --- | --- | --- |
| Participants | 255 smokers, moderate+ dependence | 84 prediabetic or overweight smokers |
| Background therapy | Varenicline + counseling | Nicotine patch + brief counseling |
| Treatment length | 12 weeks | 6 weeks |
| Effect on quitting | None (63% vs 65%) | 46.3% vs 26.8%, interval crosses 1 |
| Effect on weight | −2.9 kg at 12 weeks, gone by 52 | 5.6 lb lower at 6 weeks |

## The study that made the headlines is not a trial

In 2024 a paper in the Annals of Internal Medicine reported that semaglutide was associated with lower rates of tobacco-use-disorder care. It compared 5,967 new semaglutide users against people starting seven other diabetes drugs, out of 222,942 patients with both type 2 diabetes and a tobacco use disorder diagnosis. Against insulin the hazard ratio was 0.68; against other GLP-1 drugs it was 0.88.[4]

What it counted is the important part. The outcomes were a medical encounter recording a tobacco use disorder diagnosis, a prescription for a smoking cessation medication, and a counseling session. Those are health care events. The paper’s own limitations section records missing data on current smoking behavior.[4] It did not observe whether anyone smoked fewer cigarettes, and it does not claim to have.

> The study counted diagnoses, cessation prescriptions and counseling sessions. It did not observe whether anyone smoked fewer cigarettes.

One more detail points the same way. Most of the between-group differences appeared within 30 days of the first prescription.[4] A real effect on an addiction that people take months to break would be an odd thing to see almost entirely inside the first month. The authors are careful about this: their stated conclusion is that the findings suggest a need for clinical trials, not that the question is settled.

## Where that leaves you

- No GLP-1 is approved for smoking cessation, and none of this evidence asks for one to be.
- The best randomized evidence says a GLP-1 added to treatment that already works does not improve your odds of quitting, at 12 weeks or at a year.
- It does hold post-cessation weight while you take it. Three months of treatment did not hold it at a year.
- Gastrointestinal side effects were very common in the trial: 90% of the dulaglutide group reported them, though so did 81% of the placebo group.
- Varenicline and nicotine replacement are the therapies these trials were built on top of, because they are the ones with the evidence.

If you are already taking a GLP-1 and thinking about quitting smoking, none of this is a reason to stop either one. If you are considering starting a GLP-1 in order to quit, the trials do not support that, and the conversation to have is with the person who would prescribe it. We keep a dated price for every seller we can find on the [live price tracker](https://glpwatchdog.org/price-tracker), and the [methodology](https://glpwatchdog.org/methodology) sets out how we check them.

This question sits inside a bigger one. For what the same drugs look like across every substance class measured, including the randomized behavioral trial that missed its endpoints, see [GLP-1s and substance use](https://glpwatchdog.org/research/glp1-and-substance-use). The nearest sibling with a dedicated trial of its own is alcohol: [semaglutide and alcohol use disorder](https://glpwatchdog.org/research/semaglutide-for-alcohol-use-disorder) and [alcohol and GLP-1s](https://glpwatchdog.org/research/alcohol-and-glp1s).

## Frequently asked questions

### Do GLP-1 drugs help you quit smoking?

The best randomized evidence says no. A 255-person trial of dulaglutide added to varenicline and counseling found abstinence of 63% on the drug and 65% on placebo at twelve weeks, and 32% in both groups at one year. A smaller 84-person pilot of exenatide added to a nicotine patch reported a larger quit rate, but its credible interval included no benefit.

### Will a GLP-1 stop me gaining weight when I quit?

While you are taking it, the trial says yes. The dulaglutide group lost 1.0 kg over twelve weeks while the placebo group gained 1.9 kg. After the injections stopped, the advantage faded: it was about 1.0 kg at 24 weeks and 0.35 kg at 52 weeks, by which point both groups had gained weight from baseline.

### What about the study saying semaglutide reduced smoking?

That was a target trial emulation using electronic health records, not a randomized trial. It counted medical encounters, cessation prescriptions and counseling sessions, and its limitations section records that it had no data on current smoking behavior. Its authors concluded that clinical trials are needed.

### Did the trial find any effect on cravings?

Craving for smoking declined during treatment, but it declined in the placebo group too and there was no difference between them. That is notable because a craving mechanism was the reason the drug was expected to work.

### Is a GLP-1 approved for smoking cessation?

No. No GLP-1 receptor agonist is approved for smoking cessation or tobacco use disorder in the United States. Any use for that purpose would be off-label and is a decision for a prescriber.

## References

1. Lengsfeld S, Burkard T, Meienberg A, et al. Effect of dulaglutide in promoting abstinence during smoking cessation: a single-centre, randomized, double-blind, placebo-controlled, parallel group trial. EClinicalMedicine. 2023. PMID: 36874396. https://pubmed.ncbi.nlm.nih.gov/36874396/
2. Lüthi H, Lengsfeld S, Burkard T, et al. Effect of dulaglutide in promoting abstinence during smoking cessation: 12-month follow-up of a single-centre, randomised, double-blind, placebo-controlled, parallel group trial. EClinicalMedicine. 2024. PMID: 38371479. https://pubmed.ncbi.nlm.nih.gov/38371479/
3. Yammine L, Green CE, Kosten TR, et al. Exenatide Adjunct to Nicotine Patch Facilitates Smoking Cessation and May Reduce Post-Cessation Weight Gain: A Pilot Randomized Controlled Trial. Nicotine & Tobacco Research. 2021. PMID: 33831213. https://pubmed.ncbi.nlm.nih.gov/33831213/
4. Wang W, Volkow ND, Berger NA, et al. Association of Semaglutide With Tobacco Use Disorder in Patients With Type 2 Diabetes: Target Trial Emulation Using Real-World Data. Annals of Internal Medicine. 2024. PMID: 39074369. https://pubmed.ncbi.nlm.nih.gov/39074369/

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Cite as: GLP Watchdog, Ruth Calder, "GLP-1 Drugs and Quitting Smoking: What the Trials Actually Tested", published 2026-08-21, updated 2026-10-27. https://glpwatchdog.org/research/glp1-and-quitting-smoking

Canonical HTML page: https://glpwatchdog.org/research/glp1-and-quitting-smoking

Medical disclaimer: Nothing here is medical advice. We report on this subject; we do not treat anyone. Whether to begin a medication, supplement, or treatment, whether to adjust it, and whether to stop are questions for a clinician licensed to answer them, who knows your history.