GLP-1 & Incretin Science

GLP-1 Agonists and Alcohol Use: The Trial Evidence

JMWritten & reviewed by Jack Muncaster · Founder, UK PeptidesLast reviewed 2026-08-234 cited sources

Three randomised controlled trials have tested semaglutide in alcohol use disorder. All reported reductions in craving or heavy drinking against placebo. All were small — 48, 50 and 108 participants — and short, running 8 to 26 weeks, so they establish a signal rather than an effect size.

Key facts

Trial 1
48 participants, 9 weeks, weekly injection
Trial 2
50 participants, 8 weeks, oral semaglutide
Trial 3
108 participants, 26 weeks, plus CBT
Consistent finding
Reduced craving and heavy drinking days
Largest trial size
108 — small by any standard
Approved for this use
No, in any jurisdiction
Key references
PMID 39937469, PMID 42522065

Why anyone looked

The observation came before the hypothesis. People taking GLP-1 agonists for weight or glucose reported drinking less without intending to, consistently enough that it became a research question rather than an anecdote. That is a weak starting point epistemically — self-report from people undergoing a major metabolic intervention is confounded in obvious ways — which is why randomised trials followed.

The three trials

Hendershot and colleagues reported in JAMA Psychiatry in April 2025 on 48 non-treatment-seeking adults given low-dose weekly semaglutide over nine weeks, finding reduced alcohol consumed in a laboratory self-administration procedure and reduced weekly craving. Schacht and colleagues reported in the American Journal of Psychiatry in July 2026 on 50 people with moderate-to-severe alcohol use disorder given oral semaglutide over eight weeks, finding fewer heavy drinking days, fewer drinks per drinking day and reduced craving. A third trial randomised 108 treatment-seeking patients with comorbid obesity to semaglutide or placebo alongside cognitive behavioural therapy for 26 weeks, again reporting fewer heavy drinking days.

What size and duration mean here

Forty-eight, fifty and one hundred and eight participants are small trials. For comparison, SELECT enrolled 17,604 to establish a cardiovascular outcome. Small trials can establish that an effect exists; they are poorly suited to estimating how large it is, and they are vulnerable to chance findings. Nine weeks, eight weeks and twenty-six weeks are also short relative to a chronic condition where relapse is measured over years.

The populations were not the same

This matters more than it looks. The first trial enrolled non-treatment-seeking participants — people not currently trying to stop drinking — which is a standard early-phase design but a very different group from people in treatment. The third enrolled treatment-seeking patients receiving cognitive behavioural therapy alongside the drug. A finding in one population does not transfer automatically to the other, and the third design cannot separate the drug's contribution from the therapy's beyond what the placebo arm captures.

What the meta-analysis adds

A systematic review and meta-analysis in eClinicalMedicine in December 2025 pooled effects of GLP-1 receptor agonists on alcohol consumption. Pooling small trials increases precision but cannot fix their common limitations — if every included trial is short and small, the pooled result is a more precise estimate of a short-term effect in small samples.

Regulatory position

No GLP-1 agonist is approved for alcohol use disorder in any jurisdiction. This is an active research question with a consistent early signal, not an established indication, and material supplied for laboratory research has no relationship to it whatsoever.

Extended research context

The GLP-1 & Incretin Science deep dive

Deep dive: the two routes to a bigger effect

Every compound trying to beat GLP-1 alone has taken one of two routes. The first adds more receptors from the same hormone family — GIP in tirzepatide, GIP and glucagon in retatrutide. The second adds a non-incretin satiety hormone, which in practice means amylin: CagriSema combines cagrilintide with semaglutide, and amycretin engages both receptors from one molecule. Both routes work, because they recruit signalling pathways that do not fully overlap. Neither has escaped the constraint that binds all of them, which is that gastrointestinal tolerability worsens as effect size grows.

Deep dive: why a percentage is not a result

The most-quoted numbers in this field are the least comparable. REDEFINE 1 reported 22.7% and 20.4% for the same compound in the same trial — the first among participants who adhered to treatment, the second across everyone randomised. TRIUMPH-1 reported 28.3% in an uncomplicated obesity population while TRIUMPH-3 reported up to 22.6% in adults with established cardiovascular disease, using the same compound. Before any two figures can be compared they have to match on estimand, population, duration, comparator and whether the number is placebo-adjusted. Most published comparisons match on none of them.

Deep dive: what happens after the trial stops

Every headline figure describes weight while treatment continues. The STEP-1 extension found that a year after semaglutide was stopped, participants had given back roughly two-thirds of what they lost, moving from 17.3% mean reduction to a net 5.6% — though average weight remained below baseline and nearly half stayed at least 5% down. Meta-analysis puts regain at around 0.8 kg per month. This is why maintenance studies such as TRIUMPH-6 matter more to the field's future than another two points of peak reduction.

Research applications

  • Comparing incretin and amylin compounds on a like-for-like basis
  • Interpreting estimands, thresholds and placebo-adjusted figures in trial reports
  • Tracking the obesity pipeline across sponsors and jurisdictions
  • Understanding receptor pharmacology behind GLP-1, GIP, glucagon and amylin
  • Distinguishing licensed medicines from investigational compounds

Handling checklist

  • Identify which estimand a quoted percentage comes from before citing it
  • Check the trial population and baseline BMI against the comparison you are making
  • Confirm the duration and whether the reduction curve had plateaued
  • Read discontinuation rates alongside efficacy figures
  • Verify every NCT identifier against ClinicalTrials.gov rather than secondary reporting

Common research-handling mistakes

Learnt from thousands of researcher orders across our UK labs.

Comparing headline percentages across different trials

Fix: Population, duration, estimand and comparator all differ; the numbers are not interchangeable.

Quoting the larger of two figures from the same trial

Fix: Name the estimand. Efficacy and treatment-policy answer different questions.

Treating peak reduction as a durable outcome

Fix: Substantial regain follows cessation across the class; peak figures describe a maintained state.

Assuming an oral route means a weaker mechanism

Fix: Route and receptor count are independent. Orforglipron is weaker because it hits one receptor, not because it is a tablet.

Reading investigational compounds as available treatments

Fix: Most of this pipeline holds no authorisation anywhere; mazdutide is approved only in China.

Continue researching

Peer-reviewed guides, comparators and matched reference materials.

Related questions researchers ask

  • Which weight-loss compound produces the largest reduction?
  • What is the difference between CagriSema and amycretin?
  • What is an amylin receptor agonist?
  • How much weight is regained after stopping a GLP-1?
  • Why does CagriSema report two different percentages?
  • Why is orforglipron less effective than retatrutide?

Frequently asked questions

Does semaglutide treat alcohol use disorder?
It is not approved for that use anywhere. Three small randomised trials report reductions in craving and heavy drinking, which establishes a signal rather than an established treatment.
How strong is the evidence?
Consistent in direction across three trials, but all were small (48, 50 and 108 participants) and short. Consistency across small studies is encouraging, not conclusive.
Why would a metabolic drug affect drinking?
GLP-1 receptors are expressed in brain regions involved in reward processing as well as in appetite regulation, which is the leading mechanistic hypothesis.

Primary sources & clinical trials

Peer-reviewed research and registered trials from PubMed, ClinicalTrials.gov, PubChem, FDA and NIH. All links open in a new tab and point to the primary source, so every claim can be verified at origin.

JM

Written and reviewed by

Jack Muncaster · Founder, UK Peptides

Jack founded UK Peptides in Manchester after repeatedly receiving research compounds with missing or recycled paperwork. He is responsible for supplier selection, batch release decisions and the content published in this research library. Every article here is sourced to primary literature and every product page to a signed third-party certificate.

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