How much weight can you lose on pemvidutide?

In the MOMENTUM Phase 2 trial, pemvidutide produced dose-dependent weight loss over 48 weeks: 10.3% at 1.2 mg, 11.2% at 1.8 mg, and 15.6% at 2.4 mg, versus 2.2% for placebo. Over 50% of subjects on the 2.4 mg dose lost at least 15% of their body weight, and over 30% lost at least 20%. Body composition analysis showed 78.1% of weight lost was fat mass.

Next-Generation Obesity Peptides

Pemvidutide: The GLP-1/Glucagon Dual Agonist for MASH

14 min read|March 25, 2026

Next-Generation Obesity Peptides

54.7% liver fat reduction

Pemvidutide 1.8 mg reduced liver fat content by 54.7% versus 8.2% for placebo at 48 weeks in the IMPACT Phase 2b trial.

Harrison et al., J Hepatol, 2025

View as image

Most GLP-1 drugs on the market target a single receptor. Pemvidutide targets two. Developed by Altimmune, pemvidutide is a GLP-1/glucagon dual receptor agonist designed to treat both obesity and metabolic dysfunction-associated steatohepatitis (MASH, formerly NASH) simultaneously. In Phase 2 trials, it reduced liver fat by up to 54.7% and body weight by up to 15.6%.^[1] The FDA granted Breakthrough Therapy Designation for pemvidutide in MASH in January 2026, and a registrational Phase 3 trial is being planned. What makes pemvidutide different from semaglutide, tirzepatide, or survodutide is its balanced activation of both GLP-1 and glucagon receptors, a strategy rooted in the observation that these two hormones produce complementary effects on liver metabolism, appetite, and energy expenditure. For the broader pipeline context, see our pillar article on next-generation obesity peptides.

Key Takeaways

Pemvidutide is a balanced 1:1 GLP-1/glucagon dual receptor agonist administered as a once-weekly subcutaneous injection
In the IMPACT Phase 2b trial, pemvidutide 1.8 mg reduced liver fat by 54.7% versus 8.2% for placebo at 48 weeks (Harrison et al., 2025)
In the MOMENTUM Phase 2 trial, pemvidutide 2.4 mg produced 15.6% body weight loss at 48 weeks versus 2.2% for placebo
The glucagon receptor component drives direct hepatic effects (fat oxidation, de novo lipogenesis reduction) that pure GLP-1 agonists lack
78.1% of weight loss on pemvidutide was fat mass, with 21.9% lean mass loss, based on MRI body composition analysis
FDA granted Breakthrough Therapy Designation for MASH in January 2026; Phase 3 planning is underway

Why Add Glucagon to GLP-1?

The rationale for combining GLP-1 and glucagon receptor activation starts with a counterintuitive insight: glucagon, the hormone best known for raising blood sugar, also has powerful effects on liver fat metabolism and energy expenditure that are lost when it is blocked or ignored.

Cegla et al. (2014) demonstrated this principle in a human proof-of-concept study. They co-infused low-dose GLP-1 and glucagon into healthy volunteers and found that the combination reduced food intake more than either hormone alone. Glucagon contributed an independent energy expenditure effect, while GLP-1 offset glucagon's glucose-raising action and added appetite suppression. The net result was reduced hunger, increased metabolic rate, and stable blood glucose.^[2]

This dual mechanism is not a new idea in biology. Oxyntomodulin, a natural gut hormone released after eating, activates both GLP-1 and glucagon receptors. Zhihong et al. (2023) reviewed the emerging therapeutic potential of oxyntomodulin-based dual agonists, noting that the endogenous peptide reduces food intake, improves glucose tolerance, and increases energy expenditure in humans, but its short half-life (approximately 12 minutes) prevents clinical use in native form.^[3] Pemvidutide is essentially an engineered version of this natural dual signal, optimized for weekly dosing.

The glucagon component does something that pure GLP-1 agonists cannot: it directly activates hepatic glucagon receptors, increasing fatty acid oxidation, reducing de novo lipogenesis, and promoting lipolysis in the liver. This is why pemvidutide's liver fat reductions are substantially larger than those seen with semaglutide alone. For a deeper look at why adding receptor targets may amplify weight loss, see our article on the science behind multi-agonism.

IMPACT Trial: Liver Fat and Fibrosis Results

The IMPACT Phase 2b trial is pemvidutide's most important clinical dataset to date. Harrison et al. (2025) published the 24-week results in the Journal of Hepatology, and Altimmune reported 48-week data in December 2025.^[1]

Study design

Patients with BMI of 28 kg/m2 or higher, liver fat content of 10% or greater (measured by MRI-PDFF), and metabolic dysfunction-associated steatotic liver disease (MASLD) were randomized 1:1:1:1 to pemvidutide 1.2 mg, 1.8 mg, 2.4 mg, or placebo, administered subcutaneously once weekly.

Liver fat reduction at 24 weeks

The primary endpoint was relative change in liver fat content. At 24 weeks:

Pemvidutide 1.2 mg: approximately 37% reduction
Pemvidutide 1.8 mg: approximately 42% reduction
Pemvidutide 2.4 mg: approximately 47% reduction
Placebo: approximately 6% reduction

All doses achieved statistical significance versus placebo.

48-week results

At 48 weeks, continued treatment showed further reductions:

Pemvidutide 1.2 mg: 45.2% liver fat reduction
Pemvidutide 1.8 mg: 54.7% liver fat reduction
Placebo: 8.2% reduction

The Enhanced Liver Fibrosis (ELF) score and Liver Stiffness Measurement (LSM) both showed statistically significant improvements versus placebo, with additional reductions from the 24-week timepoint. These fibrosis markers matter because fibrosis stage is the strongest predictor of liver-related mortality in MASH patients. The 1.8 mg dose showed no evidence of effect plateauing at 48 weeks, suggesting that longer treatment may produce even greater benefits.

This level of liver fat reduction exceeds what has been reported for semaglutide alone in MASH trials. Siranart et al. (2026) conducted a meta-analysis of GLP-1 receptor agonists in histologic MASH and found that while GLP-1 agonists produce meaningful improvements, the magnitude of liver fat reduction and fibrosis improvement with dual agonists like pemvidutide appears to be larger, likely due to the direct hepatic effects of glucagon receptor activation.^[4]

For a broader look at the MASH treatment landscape, see our article on MASH and peptide solutions.

MOMENTUM Trial: Weight Loss Results

The MOMENTUM Phase 2 trial evaluated pemvidutide specifically for obesity, separate from liver disease.

At 48 weeks, mean body weight loss by dose:

Pemvidutide 1.2 mg: 10.3%
Pemvidutide 1.8 mg: 11.2%
Pemvidutide 2.4 mg: 15.6%
Placebo: 2.2%

At the 2.4 mg dose, over 50% of subjects achieved at least 15% weight loss, and over 30% achieved at least 20% weight loss.

Body composition

MRI-based body composition analysis in 50 subjects receiving pemvidutide showed that 78.1% of weight lost was fat mass, with 21.9% lean mass loss. This ratio is comparable to tirzepatide and better than many weight loss interventions where lean mass loss often accounts for 25-40% of total weight reduction. The glucagon component may contribute to lean mass preservation by promoting fat oxidation preferentially, though this has not been directly tested in pemvidutide trials.

These weight loss numbers are competitive with approved GLP-1 agonists but not category-leading. Semaglutide 2.4 mg (Wegovy) produces approximately 15-17% weight loss, and tirzepatide (Zepbound) produces 20-25% depending on dose. Pemvidutide's value proposition is not weight loss alone; it is the combination of meaningful weight loss with liver-specific benefits that no pure GLP-1 agonist can match.

How Pemvidutide Compares to Other Dual and Multi-Agonists

The GLP-1/glucagon dual agonist space has multiple competitors, each with a different receptor balance.

Survodutide (Boehringer Ingelheim) is also a GLP-1/glucagon dual agonist, currently in Phase 3 trials for both obesity and MASH. Le et al. (2026) described the baseline characteristics of participants in survodutide's Phase 3 obesity program, confirming the broad enrollment criteria designed to demonstrate efficacy across diverse patient populations.^[5] For a detailed comparison, see our article on how survodutide differs from other dual agonists.

Retatrutide (Eli Lilly) takes a different approach: it adds a third receptor (GIP) to GLP-1 and glucagon, creating a triple agonist. In Phase 2, retatrutide produced up to 24% weight loss at 48 weeks and dramatic liver fat reductions. Its inclusion of glucagon receptor activation is likely responsible for its liver-specific benefits, similar to pemvidutide. See our article on how retatrutide targets three receptors.

Tirzepatide (Eli Lilly) is a GLP-1/GIP dual agonist that does not include glucagon. It produces greater weight loss than pemvidutide (up to 25.3% in the SURMOUNT-1 trial) but lacks the direct hepatic effects of glucagon receptor activation. See our article on tirzepatide's dual mechanism.

Reytor-Gonzalez et al. (2026) reviewed single versus dual agonist pharmacotherapy for managing weight regain after bariatric surgery, noting that dual agonists offer theoretical advantages for patients who need both metabolic and hepatic improvement, though head-to-head data is limited.^[6]

The Glucagon Receptor in the Liver: Why It Matters

Understanding why pemvidutide works for MASH requires understanding what glucagon does in the liver beyond glucose regulation.

Hepatocytes express glucagon receptors abundantly. When activated, these receptors trigger a cascade that increases fatty acid beta-oxidation (burning fat for energy), decreases de novo lipogenesis (making new fat from sugars), and promotes amino acid catabolism. In a healthy liver, postprandial glucagon helps clear excess nutrients. In MASH, this clearance mechanism is impaired, and fat accumulates.

Pure GLP-1 agonists reduce liver fat primarily by reducing caloric intake and improving insulin sensitivity, which indirectly decreases hepatic fat delivery. Glucagon receptor activation adds a direct hepatic mechanism: it tells the liver cells themselves to burn fat rather than store it. This explains why pemvidutide's liver fat reductions (54.7% at 48 weeks) substantially exceed those reported with semaglutide alone in MASH populations, where reductions typically range from 30-40%.

The concern with glucagon activation has always been hyperglycemia. In a fasting state, glucagon mobilizes glucose from the liver, raising blood sugar. Pemvidutide addresses this by balancing glucagon with equal GLP-1 activity. GLP-1 stimulates insulin secretion, suppresses glucagon's glucose-raising effect, and promotes glucose disposal. In IMPACT and MOMENTUM trials, this balance held: fasting glucose and HbA1c did not increase meaningfully, even at the highest pemvidutide doses.

Safety and Tolerability

Pemvidutide's safety profile across both IMPACT and MOMENTUM trials has been generally favorable. The most common adverse events are gastrointestinal: nausea, vomiting, and diarrhea, consistent with the GLP-1 component. These events were dose-dependent and typically occurred during dose escalation, diminishing over time.

A potential concern with any glucagon-containing drug is hyperglycemia, since glucagon raises blood glucose. In pemvidutide trials, the GLP-1 component appears to offset the glucagon-mediated glucose rise. No clinically meaningful increases in fasting glucose or HbA1c have been reported. Pemvidutide also produced robust reductions in serum lipids (total cholesterol, LDL, triglycerides) and improvements in blood pressure without imbalances in cardiac events or arrhythmias.

Discontinuation rates due to adverse events were lower at 48 weeks than might be expected, with the 1.8 mg dose showing a particularly favorable tolerability profile in the IMPACT trial. This is relevant for a disease like MASH where long-term treatment will likely be required.

Regulatory Status and What Comes Next

The FDA granted Breakthrough Therapy Designation (BTD) for pemvidutide in MASH in January 2026. BTD is reserved for drugs that treat serious conditions where preliminary evidence shows substantial improvement over existing therapies. For MASH, no GLP-1/glucagon dual agonist is currently approved, making pemvidutide a potential first-in-class treatment.

Altimmune completed an end-of-Phase 2 meeting with the FDA, reaching alignment on parameters for a registrational Phase 3 trial in MASH patients with moderate to advanced fibrosis (F2-F3). The primary endpoint will likely involve histologic improvement on liver biopsy, the current gold standard for MASH drug approval.

Beyond MASH and obesity, Altimmune has initiated Phase 2 trials of pemvidutide in alcohol use disorder (RECLAIM trial, began May 2025) and alcohol-associated liver disease (RESTORE trial, began July 2025). These expansions are based on emerging evidence that GLP-1 pathway activation reduces alcohol consumption in both preclinical models and retrospective human studies, a finding with relevance across the broader GLP-1 drug class.

Limitations and Open Questions

Pemvidutide's Phase 2 data is promising but comes from relatively small trials (under 400 total subjects across IMPACT and MOMENTUM). Phase 3 will need to confirm these results in larger, more diverse populations and demonstrate histologic improvement on liver biopsy, not just changes in imaging-based liver fat measurements. The 48-week MOMENTUM data showed 15.6% weight loss at the highest dose, which is competitive but not dramatically better than semaglutide; the liver data is the stronger differentiator. No head-to-head trial has compared pemvidutide directly to semaglutide, tirzepatide, or survodutide, so all comparisons are cross-trial and subject to differences in study populations and design. The long-term safety of sustained glucagon receptor activation in the liver (beyond 48 weeks) is unknown and will require extended follow-up from Phase 3. Whether the lean mass preservation observed in MOMENTUM holds across different patient populations and longer treatment durations is also unresolved.

The Bottom Line

Pemvidutide is a GLP-1/glucagon dual receptor agonist that produces substantial liver fat reduction (54.7% at 1.8 mg) and meaningful weight loss (15.6% at 2.4 mg) in Phase 2 trials. The glucagon component provides direct hepatic effects that pure GLP-1 agonists lack, making pemvidutide particularly suited for MASH treatment. With FDA Breakthrough Therapy Designation and Phase 3 planning underway, pemvidutide represents a different approach from the GLP-1/GIP dual agonists (tirzepatide) and triple agonists (retatrutide) by prioritizing liver-specific outcomes alongside weight reduction.

Frequently Asked Questions

Pemvidutide is a once-weekly injectable peptide that activates both GLP-1 and glucagon receptors in a balanced 1:1 ratio. The GLP-1 component suppresses appetite, slows gastric emptying, and improves insulin sensitivity. The glucagon component directly increases hepatic fat oxidation, reduces de novo lipogenesis in the liver, and boosts energy expenditure. This dual mechanism produces both weight loss and liver fat reduction, as demonstrated in Phase 2 trials by Altimmune.

Pemvidutide and semaglutide produce similar weight loss (15-16% at their highest doses), but pemvidutide adds glucagon receptor activation that semaglutide lacks. This gives pemvidutide substantially greater liver fat reduction: 54.7% in the IMPACT trial versus smaller reductions reported with semaglutide in MASH studies. Semaglutide is FDA-approved and available now; pemvidutide is still in clinical trials with Phase 3 planning underway.

No. Pemvidutide is not yet FDA-approved as of March 2026. The FDA granted Breakthrough Therapy Designation for pemvidutide in MASH in January 2026, and Altimmune is planning a registrational Phase 3 trial. The drug has completed Phase 2 trials for both obesity (MOMENTUM) and MASH (IMPACT) with positive results. Additional Phase 2 trials are ongoing for alcohol use disorder and alcohol-associated liver disease.

The most common side effects in Phase 2 trials were gastrointestinal: nausea, vomiting, and diarrhea, consistent with other GLP-1-based drugs. These effects were dose-dependent and typically lessened over time. Despite containing a glucagon component, pemvidutide did not cause clinically meaningful increases in blood glucose. It also produced favorable effects on lipids and blood pressure without cardiac safety concerns.

All three drugs include glucagon receptor activation, but they differ in additional targets. Pemvidutide activates GLP-1 and glucagon only. Survodutide (Boehringer Ingelheim) also activates GLP-1 and glucagon but with different receptor balance and potency ratios. Retatrutide (Eli Lilly) adds a third target, GIP, creating a triple agonist that produces up to 24% weight loss. No head-to-head trials have compared these drugs directly.