Is pemvidutide FDA-approved, and what does the research show?

What is pemvidutide?

Pemvidutide is an investigational peptide drug made by Altimmune, which funded the IMPACT trial ² and sponsors its trials ⁴, ¹⁰, ⁷. It is a dual agonist, a single molecule built to turn on two receptors, the GLP-1 receptor and the glucagon receptor ², ³. GLP-1, glucagon-like peptide-1, is a gut hormone of the incretin class; it signals the pancreas to release insulin after eating ¹. Semaglutide works through the GLP-1 receptor, and tirzepatide through both the GLP-1 receptor and the receptor for GIP, a second gut hormone ¹.

Pemvidutide adds glucagon receptor activity to GLP-1 instead of GIP, and Altimmune describes the two activities as balanced one to one ⁶. Its early trials ran under the code name ALT-801 ⁴, ⁷.

Is pemvidutide FDA-approved?

Pemvidutide is not FDA-approved: Drugs@FDA lists no approved pemvidutide product as of November 9, 2026 ⁵. It is an investigational drug, and its first phase 3 trial, in MASH, began recruiting in 2026 ⁷. Altimmune's own releases call it "a novel, investigational peptide" ⁶. An FDA label, with its prescribing and safety information, exists only for an approved drug, and pemvidutide has none ⁵.

Altimmune says FDA granted pemvidutide Fast Track designation for MASH, announced October 26, 2023, and for alcohol use disorder, announced August 19, 2025 ¹¹, ¹². It says FDA granted Breakthrough Therapy designation for MASH, announced January 5, 2026 ⁶. Neither designation is an approval.

FDA's own page on Fast Track calls it "a process designed to facilitate the development, and expedite the review of drugs to treat serious conditions and fill an unmet medical need" ¹³. Its page on Breakthrough Therapy designation calls that "a process designed to expedite the development and review of drugs" for a serious condition where early evidence points to "substantial improvement over available therapy" ¹⁴. The company's January 2026 release names no date for a marketing application; it says the phase 3 trial is meant to support "a potential accelerated approval" ⁶.

See the FDA status of every peptide, updated weekly.

How does pemvidutide work?

Pemvidutide acts on two receptors, the GLP-1 receptor and the glucagon receptor ², ³. GLP-1 receptor agonists raise insulin release after a meal, slow the stomach's emptying, and hold back glucagon when blood sugar is high ¹. What the glucagon arm adds is proposed, not shown in a trial of its own. The trial investigators write that glucagon receptor agonists "act directly on the liver to stimulate fatty acid oxidation and inhibit lipogenesis" ³, ¹⁵. That, they say, could cut liver fat beyond what weight loss alone achieves ¹⁵.

They hypothesized that the pair might reduce liver fat more than GLP-1 activity alone ³. It might also produce more weight loss, "as glucagon-like peptide-1 (GLP-1) reduces food consumption through anorectic effects while glucagon stimulates energy expenditure" ³. IMPACT then tested pemvidutide against placebo in people with MASH ²; no trial on this page compares it with a GLP-1 drug alone.

What does the research show?

Studied in people: IMPACT, a randomized, double-blind, placebo-controlled phase 2b trial, 212 people with biopsy-confirmed MASH and liver fibrosis stage F2 or F3, liver biopsy at 24 weeks ². Randomized means assigned by chance, double-blind means neither participants nor investigators knew who had the drug, and placebo-controlled means compared with an inactive injection ². MASH, metabolic dysfunction-associated steatohepatitis, is "a progressive liver disease marked by fat accumulation, inflammation, and fibrosis in the liver," in Altimmune's description ⁶. Fibrosis is scarring, and the company describes stages F2 and F3 as moderate to advanced ⁶, ⁷.

MASH resolution without worsening of fibrosis occurred in 58% and 52% of the two pemvidutide groups, of 41 and 85 people, against 20% of 86 on placebo ². The trial's second primary endpoint, fibrosis improvement by at least one stage without worsening of MASH, was not met ². Fibrosis improved in 33% and 36% against 28%, differences the authors report as not statistically significant ². The authors write that "additional trials of longer duration are planned" ².

Participants were enrolled at 83 sites in the United States and Australia between July 2023 and April 2025 ². ClinicalTrials.gov records the trial as completed in November 2025 ¹⁰.

Altimmune's 48-week figures from the same trial, released December 19, 2025, are the company's and had not appeared in a journal as of November 9, 2026 ¹⁶. By those figures, weight fell by 4.5% and 7.5% in the two pemvidutide groups against 0.2% on placebo, and two blood and imaging markers of fibrosis improved ¹⁶. The release reports no biopsy result at 48 weeks ¹⁶.

Studied in people: a randomized, double-blind, placebo-controlled trial, 94 adults with MASLD and a BMI, body mass index, of 28 or more, liver fat by MRI scan at 12 weeks ¹⁵. MASLD, metabolic dysfunction-associated steatotic liver disease, is the fatty liver condition of which MASH is the progressive form ¹⁵. Liver fat fell by 46.6% to 68.5% across the three pemvidutide groups, against 4.4% on placebo; the largest weight loss in any pemvidutide group was 4.3% ¹⁵. Sixty-four of those participants then continued for another 12 weeks on their assigned treatment ³. At 24 weeks, liver fat had fallen by 56.3% to 76.4% across the pemvidutide groups against 14.0% on placebo, and weight by 5.1% to 6.2% ³.

Studied in people: MOMENTUM, a randomized, double-blind, placebo-controlled phase 2 trial ⁴, ⁸. It enrolled 391 adults with obesity, or overweight with at least one weight-related condition, and without diabetes, and measured weight change at 48 weeks ⁴, ⁸. Its results have not appeared in a journal, so the figures are the company's ⁸. Mean weight fell by 10.3%, 11.2% and 15.6% in the three pemvidutide groups, against 2.2% on placebo ⁸. Of pemvidutide participants, 74.1% completed the trial, against 61.9% on placebo ⁸.

ClinicalTrials.gov records the trial as completed in September 2023, with no results posted ⁴. Since December 2025, Altimmune's releases have listed MASH, alcohol use disorder and alcohol-associated liver disease as the conditions it is developing pemvidutide for, without obesity ⁶, ¹⁷.

Studied in people: RECLAIM, a randomized, double-blind, placebo-controlled phase 2 trial ⁹, ¹⁸. It enrolled 100 adults with moderate to severe alcohol use disorder and a BMI of 25 or more, and measured heavy drinking days at 24 weeks ⁹, ¹⁸. The results so far are the company's, released July 28, 2026 ⁹.

Heavy drinking days per week fell by 4.20 with pemvidutide against 2.75 with placebo ⁹. On the World Health Organization's risk drinking scale, 64.4% of the 45 pemvidutide participants assessed dropped two levels, against 34.8% of 46 on placebo ⁹. The company says it will submit the results to a journal ⁹.

RESTORE, a phase 2 trial in alcohol-associated liver disease, has enrolled 121 people and is due to complete its primary measurement in September 2027 ¹⁹. Neither alcohol trial has published results in a journal; the company's release is the only report so far ⁹.

No published trial has run beyond 48 weeks, and none was designed to test heart attacks, strokes, deaths or liver failure ², ³, ¹⁵, ⁸. The phase 3 MASH trial, which lists a clinical outcome event among its primary measures, is recruiting an estimated 1,800 people with an estimated primary completion date of December 2028 ⁷.

What are the side effects?

In the trials that report it, gastrointestinal effects were the most common adverse events ³, ⁸. In IMPACT, whose participants had MASH and fibrosis, adverse events of any kind affected 78% and 81% of the two pemvidutide groups, against 67% on placebo ². The authors describe the majority as mild or moderate ². Adverse events led none of 41 and one of 85 pemvidutide participants to stop treatment, against two of 86 on placebo ². At 48 weeks, by the company's figures, no serious or severe adverse event was judged related to treatment ¹⁶.

In MOMENTUM, whose participants had obesity or overweight without diabetes, the company reports nausea in 25.5%, 59.6% and 51.5% of the three pemvidutide groups, against 11.3% on placebo ⁸. Vomiting affected 6.1%, 27.3% and 27.8%, against 3.1% ⁸. Adverse events led 5.1%, 19.2% and 19.6% of the pemvidutide groups to stop treatment, against 6.2% on placebo, most of them in the first 16 weeks ⁸. One participant had a serious adverse event the company attributed to the drug, a case of vomiting ⁸.

The company reports no major adverse cardiac events and no imbalance in arrhythmias ⁸. Heart rate changed by 0.1 to 3.1 beats per minute in the pemvidutide groups, against a fall of 1.4 on placebo ⁸.

The MASLD trial's 12-week extension included 64 adults who had already had 12 weeks of treatment ³. Nausea was the most common adverse event during the extension, in 33.3% of pemvidutide-treated participants, mostly mild to moderate ³. Three pemvidutide participants stopped treatment because of adverse events and none on placebo, and no serious adverse event occurred ³. Two severe events in pemvidutide recipients, a Salmonella infection and high blood pressure more than three weeks after the last dose, were judged unrelated to the drug ³. Heart rate did not change significantly ³.

In RECLAIM, whose participants had alcohol use disorder, the company reports nausea in 44% of the pemvidutide group against 24% on placebo ⁹. Vomiting affected 18% against 6%, and constipation 26% against 6% ⁹. Serious adverse events occurred in two of 50 pemvidutide participants and one of 50 on placebo; the investigator judged one, low blood sodium, possibly related to the drug ⁹. Five pemvidutide participants stopped for drug-related adverse events, against none on placebo ⁹.

Because FDA has approved no pemvidutide product, no label exists from which to quote warnings or contraindications ⁵. The trial papers and company releases above are the safety record so far, and none of them says who should not take it ², ³, ⁸, ⁹.

In sport

WADA, the World Anti-Doping Agency, does not name pemvidutide on its 2026 Prohibited List ²⁰. The list names neither pemvidutide nor ALT-801 in section S2, peptide hormones, or section S4, hormone and metabolic modulators, and the words glucagon and GLP-1 do not appear in it ²⁰.

Section S0 of the list reads: "Any pharmacological substance which is not addressed by any of the subsequent sections of the List and with no current approval by any governmental regulatory health authority for human therapeutic use (e.g. drugs under pre-clinical or clinical development or discontinued, designer drugs, substances approved only for veterinary use) is prohibited at all times" ²⁰. FDA's is the only regulator's record opened here, and it shows no approval ⁵.

What JumpstartMD offers

JumpstartMD does not prescribe pemvidutide. Our peptide library covers it so you have the facts on its FDA status and the evidence, current as of November 9, 2026.

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