Pemvidutide: evidence, FDA status and research

A weekly injection being tested for fatty liver disease and weight loss. In a 212-person trial about half cleared the liver damage, versus a fifth on a dummy shot.

Sold for

Pemvidutide is pitched as a weight-loss injection that also clears fat from the liver, with the glucagon component sold as a way to lose fat while sparing muscle.

Studies say

Phase 2 trials show large reductions in liver fat and resolution of MASH in about half of treated patients versus a fifth on placebo, with moderate weight loss, which is B-grade evidence pending a confirmatory trial.

Why grade B. Two randomized, double-blind, placebo-controlled trials have been published: the IMPACT phase 2b trial in 212 patients with biopsy-confirmed MASH and a 64-patient fatty liver trial with 24 weeks of treatment. IMPACT met its MASH-resolution endpoint but not its co-primary fibrosis endpoint at 24 weeks; the smaller trial met its liver-fat endpoint. What is missing is a phase 3 trial, long-term safety data, and any peer-reviewed publication of the obesity trial. ²³

FDA. Not approved by the FDA or any other regulator for any use. Pemvidutide is an investigational once-weekly injection from Altimmune; after the phase 2b IMPACT trial in metabolic dysfunction-associated steatohepatitis (MASH), a phase 3 MASH trial (PERFORMA) began in July 2026. Phase 2 trials have also covered obesity, alcohol use disorder and alcohol-associated liver disease.

Written from 3 cited sources. Fact-checked 2026-10-27: 18 claims checked, 8 corrected. Last refreshed 2026-10-27. Not physician reviewed.

What this means for you

What people take it for: Losing weight and clearing fatty liver disease.
Can a US doctor prescribe it?: Not yet; it is still in trials.
Properly tested in people?: Partly: some human trials, with gaps: a 212-person trial lasting 24 weeks so far.

Evidence checklist

Randomised controlled trial IMPACT phase 2b, placebo-controlledyes
Human study over 100 people IMPACT 212 patientsyes
More than one research group One sponsor's phase 2 programno
Clinical outcomes, not surrogate markers MASH resolution on biopsy at 24 weeksno
Human safety data beyond case reports Small phase 2 samples; no long-term datano

Drawn from the cited studies below. A dash means the sources give no information.

What it is

Pemvidutide is a synthetic peptide that activates two hormone receptors at once: the GLP-1 receptor, the target of semaglutide, and the glucagon receptor. It is attached to a fatty acid chain so it binds albumin in the blood and lasts a week, allowing once-weekly injection. Altimmune, a Maryland biotechnology company, is developing it. ¹²

The lead indication is MASH, the inflammatory, scarring form of fatty liver disease that was formerly called NASH. Obesity and alcohol use disorder with liver disease are also being studied. Nothing is approved. The compound appears on research-chemical websites, where the material sold has no connection to the clinical program. ²

How it works

GLP-1 receptor agonists slow stomach emptying, blunt appetite in the brain and improve insulin release after meals, which is how semaglutide and liraglutide produce weight loss. Glucagon, by contrast, raises energy expenditure and drives the liver to burn fat and release stored sugar. On its own glucagon would raise blood sugar, but paired with a GLP-1 signal the insulin response offsets that. The hope with dual agonists is that the glucagon half adds direct liver fat burning and extra energy expenditure to the GLP-1 appetite effect. Pemvidutide is tuned to a roughly balanced activity at the two receptors. ¹²

What human research shows

IMPACT, published in the Lancet in late 2025, randomized 212 adults with biopsy-confirmed MASH and moderate to advanced fibrosis to one of two doses of weekly pemvidutide or placebo, without the gradual dose escalation used for most GLP-1 drugs. At 24 weeks, MASH resolved without worsening fibrosis in 58 percent and 52 percent of patients at the two doses versus 20 percent on placebo. The co-primary endpoint, fibrosis improvement without worsening of MASH, was not met: 33 and 36 percent versus 28 percent on placebo, differences that were not statistically significant. Liver fat on imaging fell sharply and body weight fell. The trial continues to 48 weeks. ²

The earlier program tested pemvidutide in people with fatty liver disease without biopsy. In the 12-week extension published in JHEP Reports, 64 participants who had completed a 12-week placebo-controlled trial continued their assigned treatment, for 24 weeks in total. Relative liver fat fell by about 56 to 76 percent across the three doses against 14 percent on placebo, more than half of patients at the middle dose reached normal liver fat, and body weight fell by 6.2 percent over 24 weeks. ³

Altimmune has reported a 48-week obesity trial in press releases with weight loss in the range of other GLP-1-based drugs, but that trial has not been published in a peer-reviewed journal in these sources and is not counted here. ²

Study	Model	Finding
IMPACT phase 2b, 24-week analysis	Humans, n=212 with biopsy-confirmed MASH and F2-F3 fibrosis, randomized double-blind placebo-controlled	MASH resolution without worsening fibrosis in 58 and 52 percent at the two doses versus 20 percent on placebo; the fibrosis co-primary endpoint was not met. ²
MASLD extension, 24 weeks total (Browne 2025)	Humans, n=64 with fatty liver disease, double-blind 12-week extension of a randomized placebo-controlled trial	Liver fat fell 56 to 76 percent versus 14 percent on placebo, with about 6 percent weight loss. ³
GLP-1 receptor agonist pharmacology	Reference review	Describes the GLP-1 mechanisms that pemvidutide shares with approved drugs in the class. ¹

Safety

The adverse events in both trials were mostly gastrointestinal, nausea and vomiting above all, as with every GLP-1-based drug, and the sponsor reported that fixed dosing without titration was tolerated. Discontinuations for side effects were low. The glucagon component raises theoretical concerns about blood sugar and heart rate; the published trials did not show a hyperglycemia signal, though the samples are small and the populations did not include people with poorly controlled diabetes. ²³

Long-term safety is unknown. The longest controlled exposure published is 24 weeks in 212 patients, which cannot detect uncommon harms, and the effects of stopping the drug on weight and liver fat have not been reported. ²

Questions for your clinician

Is there a clinical trial of pemvidutide I could join?
What approved options exist for my fatty liver disease?
What do we know about its effect on blood sugar and heart rate?

Questions people ask

How does pemvidutide differ from semaglutide?

Semaglutide activates only the GLP-1 receptor. Pemvidutide activates GLP-1 and glucagon receptors together, aiming to add direct liver fat burning and energy expenditure. There is no head-to-head trial, and pemvidutide has not reached phase 3. ¹²

Does the glucagon part protect muscle?

That is a marketing claim ahead of the evidence. The published trials measured liver fat, liver histology and total weight; they did not report body composition in a way that shows muscle was spared relative to GLP-1 drugs. ²³

Does pemvidutide treat liver scarring?

Not yet shown. In IMPACT, fibrosis improved in 33 to 36 percent of patients on pemvidutide versus 28 percent on placebo at 24 weeks, a difference that was not statistically significant, so the trial missed that co-primary endpoint. MASH resolution was the positive result. The trial continues to 48 weeks, and longer trials are planned. ²

Can I buy pemvidutide?

Research-chemical websites list it, but it is an unapproved investigational drug and anything sold that way has no verified identity, purity or dose. The only legitimate access is through a clinical trial. ²

Citations

StatPearls: glucagon-like peptide-1 receptor agonists ncbi.nlm.nih.gov
2025, Lancet: safety and efficacy of weekly pemvidutide versus placebo for MASH, 24-week results of the IMPACT phase 2b trial doi.org
Browne 2025, JHEP Reports: safety and efficacy of 24 weeks of pemvidutide in metabolic dysfunction-associated steatotic liver disease, randomized controlled trial doi.org