Pemvidutide Weight Loss & Liver Data (2026)

PIPELINE + LIVER RESULTS GUIDE · INVESTIGATIONAL MEDICINE · VERIFIED AUGUST 12, 2026

Pemvidutide Weight Loss and Liver Results: What the Trials Actually Show

The 15.6% obesity result and the 54.7% liver-fat result are real, but they came from different trials, doses, populations, and measurements. Here is what each result does — and does not — prove.

Pemvidutide weight loss and liver results come from different human trials — and that changes how the headline numbers should be read. In an obesity trial, the 2.4 mg dose averaged 15.6% weight loss at 48 weeks. In people with biopsy-confirmed liver disease, the 1.8 mg dose averaged 7.5% while liver fat fell 54.7%. Pemvidutide is not approved anywhere and cannot be prescribed.

Both of those numbers are real. Neither came from the trial you probably think it came from. And once you see which study produced which result, the whole story reads differently — including the part many summaries miss, which is what happened to the plan to develop this as a weight-loss drug.

What changes the answer

If you care about scale weight: the biggest number came from the obesity trial, at a dose the liver trial never used.
If you care about liver fat: the biggest drops came from a small early study, measured by MRI.
If you care about MASH: the liver trial hit its MASH-resolution goal.
If you care about scarring: the biopsy goal for scarring was missed. We explain that in full below.

What changes the answer
FDA status	Furthest stage	Can you get it?
Investigational. Not approved in the U.S. or anywhere else.	Phase 3 for MASH. Enrollment opened August 3, 2026.	Only inside an official Altimmune trial. No prescriptions, no pharmacy product, and no lawful U.S. compounded version for human use.

This page is for you if you want the trial numbers explained straight, you just got a fatty liver or MASH result and heard about this drug, or you're trying to figure out what's real versus hype.

This page is not for you if you want dosing, sourcing, or "stacking" advice for an unapproved peptide — we don't publish that — or you want a guaranteed approval date. Nobody has one.

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If you're here because of your own liver

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What we actually verified

We read the primary documents, not the coverage of the coverage. Specifically: Altimmune's dated press releases for the MOMENTUM obesity trial, the IMPACT liver trial at 24 and 48 weeks, the Breakthrough Therapy announcement, and the August 3, 2026 Phase 3 launch. We used the peer-reviewed papers in The Lancet, the Journal of Hepatology, and JHEP Reports for the trial results. We used the company's SEC filings for program status. We used the FDA-approved Wegovy label and the American Association for the Study of Liver Diseases (AASLD) November 2025 practice guidance for what's available today.

We kept the obesity results and the liver results in separate columns, and we kept biopsy findings separate from scan findings. Those are not the same kind of evidence, and blending them is how the internet got this drug wrong.

Where a number has only been reported by the company and not yet published in a journal, we say so on the line.

Pemvidutide weight loss and liver results, sorted by trial

Pemvidutide has been studied in five main human trials, and each one asked a different question in a different group of people. The obesity trial measured scale weight. The liver studies measured liver fat, inflammation, and scarring. The Phase 3 trial that began in August 2026 has no results yet. That is why the numbers online don't match — they were never supposed to.

Here is the whole evidence base in one table. This is the part of the page we'd want if we were the reader.

Pemvidutide weight loss and liver results, sorted by trial
Trial	Who was in it	Dose and length	Weight result	Liver result	Tolerability	Evidence status	What it does not prove
Phase 1b MASLD (NCT05006885, Journal of Hepatology, 2025; online 2024)	94 adults with fatty liver, liver fat 10% or higher, BMI 28+	1.2 / 1.8 / 2.4 mg weekly, 12 weeks	Best dose: −4.3%	At 1.8 mg: 94.4% cut liver fat by 30%+, 72.2% cut it by half, 55.6% reached a normal liver-fat level (5% or less). Placebo: −4.4%	No severe or serious side effects reported	Peer-reviewed	Nothing about scarring. No biopsies. Twelve weeks is short.
24-week extension (NCT05292911, JHEP Reports, 2025)	64 people who continued from the study above	Same doses, 24 weeks total	−6.2% overall	Liver fat fell 56.3% / 75.2% / 76.4% vs 14.0% on placebo	Safety findings are limited by the 64-person sample	Peer-reviewed	Not a MASH trial. No biopsy endpoint. No outcome data.
MOMENTUM — obesity	391 adults with obesity or excess weight plus one related condition, no diabetes	1.2 / 1.8 / 2.4 mg weekly, 48 weeks	−10.3% / −11.2% / −15.6% vs −2.2% on placebo	Liver fat was not the focus of this trial	Adverse-event discontinuations: 5.1% / 19.2% / 19.6% vs 6.2% placebo	Company-reported; conference data	It does not tell you what a person with MASH would lose. Different disease, different doses.
IMPACT — MASH Phase 2b (NCT05989711, The Lancet)	212 adults with biopsy-confirmed MASH and stage F2–F3 scarring, with and without diabetes	1.2 and 1.8 mg only — no 2.4 mg arm, 48 weeks	24 wk: −4.8% / −5.8% vs −0.5%. 48 wk: −4.5% / −7.5% vs −0.2%	MASH cleared in 58% / 52% vs 20% placebo. Scarring improved in 33% / 36% vs 28% — not statistically significant. Liver fat at 48 wk: −45.2% / −54.7% vs −8.2%	Adverse-event discontinuations at 24 wk: 0% / 1% vs 2%. At 48 wk: 0% / 1.2% vs 3.5%	Peer-reviewed at 24 weeks; company-reported at 48 weeks	The 48-week scarring signals came from blood tests and scans, not a second biopsy.
PERFORMA — MASH Phase 3	Adults with MASH and F2–F3 scarring. About 1,790 people planned	Steps up from 1.2 mg to 1.8 or 2.4 mg. Primary look at 52 weeks	Not the main goal	Designed to test scarring improvement, MASH clearing, and real liver outcomes	No results yet	Active; no results	Nothing yet. A 52-week readout is expected in 2029. Approval is not guaranteed.

Two more trials sit outside the weight-and-liver question but explain where this drug is headed. RECLAIM tested pemvidutide 2.4 mg for alcohol use disorder and reported a positive main result on July 28, 2026. RESTORE, in alcohol-associated liver disease, completed enrollment in July 2026 and expects topline data in the second half of 2027.

The five questions to ask about any pemvidutide number

We built this because we needed it ourselves. Any time you see a pemvidutide figure — in a headline, a forum post, a video — ask:

Which trial? Obesity and liver trials are not interchangeable.
Which patients? Diabetes in or out. Liver disease confirmed or not.
Which dose? 1.2, 1.8, and 2.4 mg produced very different results.
Which week? 12, 24, and 48 weeks tell different stories.
What was measured? A biopsy is not a scan. A scan is not a blood test.

Miss any one of those and the number can mislead you. Save this five-question check. It is the fastest way to test a new pemvidutide headline without trusting the headline.

What is pemvidutide, and why does it show up in both weight-loss and liver news?

Pemvidutide, earlier called ALT-801, is an investigational once-weekly injection made by Altimmune. It's designed to switch on two receptors at once — GLP-1 and glucagon — in an even 1-to-1 balance. The GLP-1 side is linked to appetite and weight. The glucagon side is being studied for direct effects in the liver. It has not been approved for any use.

Think of a receptor as a switch on the outside of a cell. Some familiar medicines, including Wegovy and Ozempic, flip one switch. Pemvidutide was built to flip two.

The GLP-1 switch does what you'd expect if you've read anything about Wegovy or Ozempic: it turns down appetite.
The glucagon switch is the unusual part. Glucagon activity in the liver is being studied for its effect on how the liver handles fat.

That two-switch design is why the same drug name shows up in weight-loss articles and liver-disease articles in the same week. The company ran trials in both directions.

Some numbers that put the program in context: as of December 31, 2025, more than 700 people had received pemvidutide across eight completed and two ongoing studies, according to Altimmune's annual filing. Altimmune picked up the molecule when it acquired Spitfire Pharma in July 2019. You'll also see the old code names ALT-801 and SP-1373 in older documents.

MASLD, MASH, and fibrosis are three different things

This trips up almost everyone, and you can't read the liver results without it.

MASLD — extra fat in the liver, tied to metabolic health. Formerly called NAFLD. Very common.
MASH — that fat plus inflammation and cell damage. Formerly called NASH. This is the stage that does real harm.
Fibrosis — scar tissue building up from the damage. Staged F0 through F4. F4 is cirrhosis.

The key line, and hold onto it for the rest of this page: less liver fat is encouraging, but it does not automatically mean scar tissue got better. Those are separate measurements with separate evidence.

Pemvidutide weight loss results: how much did people lose?

The largest reported pemvidutide weight-loss result was 15.6% at 48 weeks on the 2.4 mg dose, in the MOMENTUM Phase 2 obesity trial. The 1.2 mg and 1.8 mg groups averaged 10.3% and 11.2%, against 2.2% on placebo. Those 391 participants had obesity or excess weight with a related condition, and none had diabetes.

Here's the dose ladder, including how many people hit the milestones people actually care about:

Pemvidutide weight loss results: how much did people lose?
Weekly dose	Average weight change at 48 weeks	Lost 15% or more	Lost 20% or more
Placebo	−2.2%	2.0%	2.0%
1.2 mg	−10.3%	21.4%	10.0%
1.8 mg	−11.2%	28.6%	9.5%
2.4 mg	−15.6%	51.8%	32.1%

The responder percentages use smaller Week 48 analysis groups than the full randomized groups: 51 people on placebo, 70 at 1.2 mg, 63 at 1.8 mg, and 56 at 2.4 mg.

Look at the jump from 1.8 to 2.4 mg. The average moved about four points, but the share of people losing 20% or more roughly tripled. That top dose was doing something the middle doses weren't.

What 15.6% looks like in pounds. At 200 pounds, 15.6% is about 31 pounds. At 250 pounds, about 39 pounds. That's arithmetic on a trial average, not a forecast for you — trial averages include people who lost far more, people who lost almost nothing, and people who stopped.

The honest catch on that 15.6% number

Here's the thing most write-ups leave out, and we'd rather you hear it from us.

The dose that produced 15.6% also had the highest adverse-event discontinuation rate. In MOMENTUM, 19.6% of the 2.4 mg group stopped treatment after an adverse event. The 1.8 mg group was 19.2%. Placebo was 6.2%. Roughly one in five people on the two highest doses stopped treatment after an adverse event. That's not a footnote. That's a real cost attached to the biggest number on this page.

Now the part that makes it interesting rather than disqualifying.

MOMENTUM gave 1.2 and 1.8 mg with no dose step-up. The 2.4 mg arm used only a four-week step-up. If tolerability is your top priority, an approved medicine with a proven step-up ladder is the better path today, and we'd point you to our best GLP-1 for fatty liver guide instead. But look at what happened when the liver trial used lower doses: at 48 weeks, adverse-event discontinuations were 0% and 1.2% — below the 3.5% seen on placebo. Same drug. Different dose. Almost nobody quit.

And the Phase 3 trial addresses the gap directly. PERFORMA adds a one- or two-step monthly step-up from 1.2 mg to 1.8 or 2.4 mg — something IMPACT never used.

Why do some reports say 15.6% and others say 7.5%?

Both figures are accurate. They came from different trials. The 15.6% came from the 2.4 mg arm of an obesity trial in adults without diabetes. The 7.5% came from the 1.8 mg arm of a liver trial in people with biopsy-confirmed MASH and moderate-to-advanced scarring. They are not competing claims and should never be compared directly.

Why do some reports say 15.6% and others say 7.5%?
	The 15.6% result	The 7.5% result
Trial	MOMENTUM	IMPACT
Main condition	Obesity or excess weight	Biopsy-confirmed MASH, F2–F3 scarring
Diabetes	Excluded	43% had type 2 diabetes
Dose	2.4 mg	1.8 mg
Length	48 weeks	48 weeks
What the trial was built to measure	Weight	Liver inflammation and scarring
The catch	Roughly 1 in 5 stopped after an adverse event at this dose	Lower dose, sicker livers; the 48-week scarring data came from scans, not biopsy

The single most useful fact in that table: the liver trial never tested 2.4 mg. So there is no 48-week result showing what the strongest dose does in a MASH patient's liver. PERFORMA is the first trial that will answer that, and it just started.

What did pemvidutide do to liver fat?

Pemvidutide produced large drops in liver fat in every study that measured it. In a 24-week extension study of 64 people, liver fat fell 56.3%, 75.2%, and 76.4% at the 1.2, 1.8, and 2.4 mg doses, against 14.0% on placebo. In the larger MASH trial at 48 weeks, liver fat fell 45.2% and 54.7% at 1.2 and 1.8 mg, against 8.2% on placebo. These were imaging results, not proof that scarring reversed.

Liver fat here was measured by MRI-PDFF — a specialized MRI scan that estimates what percent of your liver is fat. It's the standard research tool for this, and it's far more precise than the ultrasound most people get first.

The relative-versus-absolute trap

A "76% liver fat reduction" does not mean three-quarters of your liver vanished. Here's what it means:

If your liver fat starts at 20% and drops to 5%, that's a 15-point absolute drop and a 75% relative reduction. Same result, two ways of saying it. Trials report relative change because that was the planned measure used to judge response.

Every big liver-fat percentage you'll read about this drug — and about its competitors — is the relative kind. Once you know that, the numbers stop sounding like magic and start being comparable.

The finding that made us look twice

In the earliest 12-week study, on the 1.8 mg dose, participants had lost about 4.3% of their body weight. That's modest. But by that point 72.2% of them had cut their liver fat in half, and 55.6% had reached a normal liver-fat level of 5% or less.

Big liver change on small weight change. In the 24-week extension at 1.8 mg, 84.6% had cut liver fat by half or more and 53.8% were at or under 5%.

That pattern is consistent with the idea behind the drug's design — that the glucagon side does something in the liver beyond what the weight loss alone would do. We want to be careful here: consistent with is not the same as proven. These were small studies without a design built to separate the two effects. But it's a real observation, it's in the peer-reviewed record, and it's the strongest argument for why this drug is being developed as a liver drug rather than a weight drug.

What less liver fat does not prove

It does not prove MASH went away.
It does not prove scar tissue improved.
It does not prove cirrhosis was prevented.
It does not predict your result.
It does not establish that the drug will be approved.

Did pemvidutide clear MASH or improve liver scarring?

At 24 weeks in the IMPACT trial, pemvidutide met one of its two main goals and missed the other. MASH cleared without worsening scarring in 58% of the 1.2 mg group and 52% of the 1.8 mg group, versus 20% on placebo — a clear win. Scarring improvement without worsening MASH came in at 33% and 36% versus 28% on placebo, which was not statistically significant.

This is the section that separates an honest page from a hype page, so let's be precise.

The IMPACT trial had two main goals, both judged at 24 weeks on paired liver biopsies:

Did pemvidutide clear MASH or improve liver scarring?
Goal at 24 weeks	Placebo	1.2 mg	1.8 mg	Result
MASH cleared, scarring not worse	20%	58%	52%	Met — statistically significant
Scarring improved by at least one stage, MASH not worse	28%	33%	36%	Missed — not statistically significant

"MASH cleared" means a pathologist looking at the biopsy no longer saw active MASH by the study's definition, and the person's scarring hadn't gotten worse. That is a genuine and meaningful result. It is not the same as "cured."

The second goal is the one people care most about long-term, because scarring is what leads to cirrhosis and liver failure. Pemvidutide's numbers were higher than placebo, but the treatment-placebo gaps were only 5 and 8 points, and neither comparison reached statistical significance. Note the placebo rate: 28% improved their scarring by a stage. That high response made the drug-placebo gap small.

The dose oddity hidden by “up to 58%”

Read the resolution row again. 58% on the lower dose. 52% on the higher dose.

The lower dose scored better on the biopsy. Most machine-measured outcomes — liver fat, liver stiffness, ELF, cT1, and weight — favored the higher dose at 48 weeks. ALT was nearly the same at the two doses. The one biopsy number went the other way.

Three honest readings, and you deserve all three:

The 1.2 mg group was the smallest arm in the trial. With a small group, a difference like this can easily be noise.
This kind of biopsy scoring involves human judgment, and the swing between 52% and 58% is within the range where that matters.
Phase 3 uses 1.2 mg only as a starting step, then moves people up to 1.8 or 2.4 mg.

We're flagging it because you'd want to know, and because a page that only reports "up to 58% MASH resolution" is quietly hiding which arm produced it.

What changed at 48 weeks, and what didn't

At 48 weeks the trial reported more improvement, but it's important to know what kind. There was no second biopsy at 48 weeks. The later findings came from blood tests and scans:

ELF score (a blood test that estimates liver scarring): −0.49 / −0.58 at 1.2 / 1.8 mg versus +0.16 on placebo.
Liver stiffness by FibroScan (an ultrasound-based scan; stiffer usually means more scarring): −3.04 / −3.97 kPa versus −0.03 kPa.
Combined responders — people who hit both a 0.5-point ELF drop and a 30% stiffness drop: 27.8% / 32.4% versus 3.2% on placebo.
ALT (a blood enzyme that rises when liver cells are stressed): −37.8 / −37.4 IU/L versus −10.3 IU/L.
cT1 (an MRI measure of liver inflammation and fluid): −124 / −140 milliseconds versus −21 milliseconds.

Those are meaningful, and the 3.2% placebo response rate on the combined measure is striking. But blood tests and scans are supporting evidence. They are not the biopsy endpoints used for current accelerated-approval decisions in MASH, and no honest page should present them as if they were. The 48-week figures also come from the company's own report rather than a peer-reviewed publication, and we've labeled them that way throughout.

Two people who ran these trials, on the record:

Mazen Noureddin, MD, principal investigator on IMPACT and a professor of medicine at Houston Methodist Hospital, said of the blood-and-scan results that these markers have been shown to "correlate with histologic fibrosis stage" — in plain terms, they track with what a biopsy would show. (Altimmune release, December 19, 2025.)

Naim Alkhouri, MD, a principal investigator on the Phase 3 trial, framed the goal as needing "therapies that can effectively address both liver disease and the broader metabolic dysfunction." (Altimmune release, August 3, 2026.)

Both are investigators in the pemvidutide program. Their statements are expert context, not independent proof. The trial numbers above are the evidence.

What side effects showed up in pemvidutide trials?

Stomach and gut effects were the main issue. In the obesity trial at 1.8 and 2.4 mg, nausea affected 59.6% and 51.5% of participants and vomiting affected 27.3% and 27.8%. One drug-related serious side effect — vomiting — occurred in the 2.4 mg group. In the liver trial, which used lower doses, 24-week adverse-event discontinuations were 0% and 1% versus 2% on placebo. At 48 weeks, the company reported 0% and 1.2% versus 3.5%, with no serious or severe treatment-related side effects.

Here's the obesity trial's side-effect picture, by dose:

What side effects showed up in pemvidutide trials?
Side effect	Placebo	1.2 mg	1.8 mg	2.4 mg
Nausea	11.3%	25.5%	59.6%	51.5%
Vomiting	3.1%	6.1%	27.3%	27.8%
Diarrhea	5.2%	8.2%	10.1%	18.6%
Constipation	8.2%	17.3%	13.1%	22.7%
Stopped treatment after an adverse event	6.2%	5.1%	19.2%	19.6%

And the same drug in the liver trial, at 1.2 and 1.8 mg with no step-up: the peer-reviewed 24-week rates were 0% and 1%, against 2% on placebo. At 48 weeks, the company reported 0% and 1.2%, against 3.5% on placebo.

Why so different? We won't invent a mechanism. What we can say for certain is that the populations differed, the trial designs differed, and the liver trial had no 2.4 mg arm at all. Anyone telling you pemvidutide "solved" tolerability is going past the evidence. What's fair to say is that at 1.2 and 1.8 mg, in that population, almost nobody quit.

What still isn't known

Long-term safety beyond about a year.
Rare side effects that only show up in thousands of patients.
Whether it's safe in cirrhosis — those patients were excluded from these trials.
How it behaves outside a monitored trial, where nobody's checking labs on schedule.
Whether the Phase 3 safety picture matches Phase 2.

Is pemvidutide FDA approved, and can a doctor prescribe it?

No. Pemvidutide is investigational and has not been approved by the FDA or any other regulator. It has FDA Fast Track designation for MASH and alcohol use disorder, plus Breakthrough Therapy designation for MASH — both speed up development, and neither is approval. Altimmune's published expanded access policy limits pemvidutide to people enrolled in its ongoing trials.

There is no approved pemvidutide product, no FDA label, no pharmacy stock, and no approved-product price. A doctor who wanted to prescribe it has nothing to prescribe.

What Breakthrough Therapy designation actually means

This one gets misread constantly, usually on purpose.

What Breakthrough Therapy designation actually means
It does mean	It does not mean
The FDA will work more closely with the company on development	The drug is approved
Early evidence looked promising enough to justify faster development	Long-term benefit is proven
Review steps may move faster later	A doctor can prescribe it
The condition is serious and the drug may offer a substantial improvement over available therapy	The Phase 3 trial will succeed

The designation was granted based on the 24-week IMPACT data. It's a real vote of confidence. It is not a finish line.

Can you get it through expanded access?

Expanded access — sometimes called compassionate use — is a pathway where a seriously ill person who can't join a trial gets an unapproved drug anyway, with FDA and company sign-off. Companies developing drugs at this stage are required to publish their policy.

Altimmune says pemvidutide is available only to people taking part in its ongoing trials and that it is not currently considering expanded-access requests. Policies can change, so recheck the company's page rather than trusting any article — including this one — as your final word on it.

Your access question is now answered: there is no lawful way to get this drug for treatment today outside a trial. That means the useful next question is what you can do.

→ See which FDA-approved treatment paths fit your situation — answer a few questions about your state, your insurance, your diagnosis, and your budget, and get a matched path with source-verified pricing. No provider gets your information unless you choose one.

Is pemvidutide still being developed as a weight-loss drug?

Not right now — and this is the most important thing on this page for anyone searching for pemvidutide as a weight-loss option. In November 2024, Altimmune announced it had completed an end-of-Phase-2 meeting with the FDA and agreed on the design of a Phase 3 program for pemvidutide in obesity: four trials, roughly 5,000 participants, 60 weeks each, testing all three doses. As of August 12, 2026, no obesity Phase 3 trial is active or enrolling, and the company lists pemvidutide in development for MASH, alcohol use disorder, and alcohol-associated liver disease.

We want to be exact about this, because it's easy to overstate.

What the company said in November 2024: the FDA had reviewed the data from six completed trials and agreed on a four-trial registrational obesity program of about 5,000 people. Two of those planned trials were specifically interesting — one aimed at people with obesity and elevated liver fat, another at body composition including older adults with low muscle mass.

What the company says now: its filings and releases through 2026 describe pemvidutide as being in development for MASH, AUD, and ALD. Obesity is not listed among the current indications. The filings add that the company "may also pursue additional indications." The Phase 3 program that did start, in August 2026, is the liver trial.

What that means for you, plainly: there is no active or enrolling obesity Phase 3 trial right now. The registrational trial that is running is for MASH. That is the only approval path with a public Phase 3 program today.

What did not happen: nobody announced that pemvidutide failed in obesity, and nobody announced the obesity program was cancelled. The public record shows a planned obesity program that has not started, not a failed obesity drug.

If you came here hoping for a new weight-loss option, that's the honest answer — and there are approved ones you can actually get. Our pemvidutide alternatives guide lays out what's available now, by goal and by cost.

Can you buy pemvidutide online? Is it hitting the gray market?

No, there is no lawful U.S. way to buy pemvidutide for human use. It has no FDA approval and no approved product for a pharmacy to dispense. Laboratory chemical suppliers list it as a research reagent with language like "for research use only" and "we do not sell to patients."

We're not going to walk you through the gray market or name places selling it. Here's what we will tell you, because it's what actually protects you.

Why it can't lawfully be compounded in the U.S. today. The law does not require every compounding ingredient to already be an approved drug. But the ingredient still has to fit a legal route. For a 503A pharmacy, that means an applicable USP or NF monograph, a component of an FDA-approved drug, or FDA's 503A bulk-substance route. For a 503B outsourcing facility, it must be used for a drug on FDA's shortage list or appear on the 503B bulk-substance list. We found no applicable monograph or shortage route for pemvidutide. It is not a component of an FDA-approved drug, and it does not appear by name on FDA's current 503A or 503B lists or interim categories. We found no lawful U.S. route to compound it for human use. FDA-approved medicines and compounded medicines are different categories with different rules and different evidence behind them — and pemvidutide is in neither.

What suppliers themselves say. Pemvidutide appears in chemical catalogs under ALT-801, CAS number 2538014-94-5, sold by the milligram as a research reagent. Those listings carry the suppliers' own disclaimers: research use only, not for human use, not for sale to patients. Those aren't warnings we wrote. They're the sellers' own words.

The three things the label does not prove. If a vial arrives at your door with "pemvidutide" on the label, the label alone does not verify:

Identity — whether the contents are the molecule on the label.
Dose — whether the milligram amount is what it says, which matters enormously for a drug where 1.2, 1.8, and 2.4 mg produced very different dropout rates.
Sterility — whether it's safe to inject.

Every result on this page came from a specific manufactured product, made under trial conditions, given to monitored patients with scheduled lab work. None of that transfers to an unverified vial. The trial data is not a safety record for something you bought online.

If your liver is the reason you're here, this is exactly the wrong risk to take. Liver disease is monitored with labs, scans, and sometimes biopsies over months. That process is the whole point, and it doesn't work if the drug is unknown.

Can I join the pemvidutide Phase 3 trial?

Possibly. Altimmune began enrolling the PERFORMA Phase 3 trial on August 3, 2026, for adults with MASH and moderate-to-advanced scarring (F2–F3). It plans to enroll about 1,790 people across two groups. Screening is demanding: the earlier Phase 2b trial screened 1,557 people to enroll 212.

Do that math with us, because it sets expectations honestly. 1,557 screened, 212 enrolled — 13.6%. About seven people were screened for every one enrolled. A MASH trial needs confirmed disease at a specific stage, so screening removes many people who do not match the protocol.

What PERFORMA is actually built to do

This design is worth understanding, because it tells you when this drug could realistically arrive:

Two groups running side by side. Group one, about 990 people, needs liver biopsies and carries the main goal: MASH clearing and/or scarring improvement at 52 weeks. Group two, about 800 people, is selected using scans and blood tests rather than biopsy, and adds to the safety record.
Doses. A one- or two-step monthly step-up from 1.2 mg to either 1.8 or 2.4 mg — the first time the 2.4 mg dose gets tested for a full year in liver patients.
A standardized biopsy reader. The trial uses the FDA-qualified AIM-MASH AI Assist tool to help score biopsies consistently.
Two finish lines. An interim look supports a possible accelerated approval — a conditional FDA green light based on a lab or biopsy measure that's expected to predict real benefit. Full approval depends on actual liver events, tracked out to about 60 months.
Placebo. It's a placebo-controlled trial. Volunteers may receive placebo.

How to find out if you're eligible

Bring these four questions to your doctor or a hepatologist (a liver specialist):

Do my records confirm MASH, not just fatty liver?
What is my fibrosis stage, and what evidence establishes it?
Am I cirrhotic? Trials at this stage exclude cirrhosis.
Is there a trial site within a distance I could realistically travel to for a year of visits?

→ Check Altimmune's official clinical trials page for PERFORMA enrollment information. As of our August 12, 2026 check, we could not locate a public ClinicalTrials.gov record for PERFORMA, even though the company has confirmed enrollment is open.

One reality check: a trial is not a treatment plan. You may get placebo, the visit schedule is heavy, and enrollment closes.

When could pemvidutide be available?

There is no reliable date, and any specific year you see is someone's guess. Altimmune expects the 52-week Phase 3 readout in 2029. An application and FDA review would still have to follow supportive results. Full approval depends on liver-outcome data tracked to roughly 60 months.

Here's the arithmetic, so you can judge for yourself instead of trusting a number:

When could pemvidutide be available?
Step	Status
Phase 3 enrollment opens	Done — August 3, 2026
Finish enrolling about 1,790 people	Not announced
Every participant completes 52 weeks	Follows enrollment
52-week results	Company expects 2029
Application filed with the FDA	No filing date; would require supportive results first
FDA review	No review timeline until an application is filed and accepted
Earliest U.S. availability	No company or FDA date
Full approval on liver outcomes	Depends on events tracked to about 60 months

That uncertainty carries real weight. Phase 3 trials fail. PERFORMA has to meet its prespecified biopsy endpoint or endpoints. Phase 2 did not show statistically significant categorical scarring improvement.

And a faster regulatory pathway can shorten a review. It cannot produce a positive result.

The timeline so far

2023 — 48-week obesity results (MOMENTUM).
June 2025 — 24-week liver biopsy results (IMPACT). One goal met, one missed.
November 2025 — 24-week results published in The Lancet.
December 2025 — 48-week liver follow-up reported.
January 2026 — Breakthrough Therapy designation for MASH.
May 2026 — additional 48-week metabolic data presented at EASL 2026.
July 28, 2026 — positive main result in alcohol use disorder (RECLAIM).
July 2026 — RESTORE enrollment completed; topline data expected in the second half of 2027.
August 3, 2026 — Phase 3 liver trial opens enrollment.
2029 — expected 52-week Phase 3 readout.

How does pemvidutide compare to Wegovy, Zepbound, and Rezdiffra?

Pemvidutide can't be compared as a treatment choice, because it isn't one yet and no trial has tested it head-to-head against any of these. Two drugs have FDA-approved MASH indications: Rezdiffra since March 2024 and Wegovy since August 2025. Zepbound is approved for weight management, not MASH.

How does pemvidutide compare to Wegovy, Zepbound, and Rezdiffra?
Medicine	How it works	Status that matters to you	Available now?
Pemvidutide	GLP-1 + glucagon, balanced 1:1	Investigational. Phase 3 for MASH, enrolling.	No — trials only
Wegovy injection (semaglutide 2.4 mg)	GLP-1	FDA approved under accelerated approval for adults with noncirrhotic MASH and moderate-to-advanced scarring (F2–F3)	Yes, by prescription
Rezdiffra (resmetirom)	Liver-targeted thyroid hormone receptor-beta	FDA approved for adults with noncirrhotic MASH and moderate-to-advanced scarring, with diet and exercise. Not a weight-loss drug.	Yes, by prescription
Zepbound (tirzepatide)	GIP + GLP-1	FDA approved for weight management and other labeled uses. Not approved for MASH.	Yes, by prescription

Why we won't put the percentages side by side

We could easily build a table with pemvidutide's 58% next to Wegovy's 63% and let you draw a conclusion. Plenty of pages do. It would be misleading, and here's exactly why:

Different lengths. Pemvidutide's biopsy result was at 24 weeks. Wegovy's was at 72 weeks. Longer trials give the liver more time to change.
Different patients. Different diabetes rates, baseline scarring, and body weight.
Different doses, with no shared reference point.
Different math. Trials handle dropouts and missing data differently, and those choices move the headline number.
No randomization between them. Nobody was ever assigned to pemvidutide-or-Wegovy in the same trial.

Cross-trial percentage comparisons are a serious error in coverage of this drug. We're not going to make it, and you should be skeptical of any page that does.

→ Compare the treatment paths you can actually get now — approved options by goal, cost, and who each one fits.

What can you actually do about a fatty liver right now?

If a doctor has confirmed MASH with moderate-to-advanced scarring, Wegovy injection is the only GLP-1 medication with that use in its FDA label. It received accelerated approval on August 15, 2025. In the FDA label, 63% of participants had MASH clear without worse scarring versus 34% on placebo, and 37% had scarring improve versus 22%, at 72 weeks. Rezdiffra is an approved non-GLP-1 option. Whether either fits you depends on your confirmed stage and your coverage.

Notice what Wegovy did that pemvidutide hasn't: in a Phase 3 interim analysis, it hit both biopsy goals, including the scarring one. That's the evidence behind the approved indication today.

How doctors decide you're in the F2–F3 group

This is the practical gate on everything above. In its November 2025 practice guidance on semaglutide for MASH, the AASLD said most patients should be identified using non-invasive tests rather than biopsy, and gave ranges that suggest moderate-to-advanced scarring:

FibroScan (VCTE): about 8 to 15 kPa
MR elastography: about 3.1 to 4.4 kPa
ELF blood test score: about 9.2 to 10.5

These are treatment-selection ranges, not a diagnosis by themselves. If you've had any of these, those numbers are probably on your results. Ask for them. If you haven't had any of them, that's the conversation to have — because "a little fat on your liver" from a routine ultrasound is a completely different situation from confirmed MASH with F2–F3 scarring, and it leads to a different plan. Our best GLP-1 for fatty liver guide walks through the decision stage by stage.

The honest limitation on the Wegovy path

Wegovy's MASH indication came through accelerated approval, which means the FDA cleared it based on biopsy improvement while a longer trial confirms it prevents real liver events. That confirmatory data isn't expected until 2029. It's also a weekly injection with real gut side effects, and it's approved for noncirrhotic patients — not people with cirrhosis.

If you want a liver-targeted medicine that isn't a GLP-1 and is not approved as a weight-loss drug, Rezdiffra is the approved option to raise with your doctor, and our fatty liver guide covers it. If you don't have a confirmed diagnosis yet, none of this applies to you yet — get the staging done first.

But if you and your doctor are looking at an approved GLP-1 for MASH, coverage can turn on the paperwork. An insurer may want documentation of your diagnosis and stage and may require prior authorization.

→ Check what your insurance covers before you commit (affiliate link). Ro has an insurance team that checks coverage and handles prior-authorization paperwork, plus a free GLP-1 insurance coverage checker. Ro Body membership is $39 for the first month, then $149 month to month or as low as $74/month on the annual plan paid up front; medication costs extra (verified August 12, 2026).

One thing we won't pretend: no telehealth service prescribes based on a website. A licensed clinician reviews your history and decides what's appropriate, and for a MASH indication you'll need your liver records. If you don't have them yet, start with your primary care doctor or a hepatologist. Coverage details also change — for the full insurance picture, see our guide on whether insurance covers GLP-1s for fatty liver.

Are pemvidutide reviews trustworthy?

Pemvidutide has no approved-product review pool. A trial participant can describe an experience, but someone in a blinded trial may not know whether they received pemvidutide or placebo, and a gray-market story does not establish that an unverified vial matched the trial drug. Treat online “reviews” as stories, not evidence.

We looked. We're telling you what we found instead of manufacturing something.

This matters more than it sounds. A review of a gray-market vial is not evidence about the trial drug — the post does not establish what was in the vial. And in a blinded trial, a participant's story cannot show that pemvidutide caused what they felt, because they may have been on placebo.

So instead of testimonials, here's the closest thing to a large exposure count that exists: as of December 31, 2025, more than 700 people had received pemvidutide across eight completed and two ongoing studies, per Altimmune's annual filing. The two statements from trial investigators above are labeled as what they are — expert context from people involved in the program, not independent proof and not patient outcomes.

If we publish a first-hand account of this drug, it will be labeled as an anecdote, not evidence.

How we verified this page

We separated every result by trial, population, dose, week, and type of measurement. We used peer-reviewed publications where they exist, the FDA-approved label for approved comparisons, and dated company disclosures for newer findings — clearly labeled as company-reported when a journal hasn't published them yet.

Our source order, highest first:

FDA approval records and approved labels.
Peer-reviewed publications — The Lancet, Journal of Hepatology, JHEP Reports.
Clinical trial registry records.
Dated company press releases and SEC filings, for findings not yet published.
Medical trade coverage — used to check ourselves, never as the source of a number.
Patient forums — used only to learn which questions people are actually asking. Never as medical evidence.

One conflict we had to resolve, and how

The 24-week IMPACT figures have been reported two slightly different ways. The company's June 2025 press release cited MASH resolution of 59.1% and 52.1% versus 19.1% on placebo, with scarring improvement of 31.8% and 34.5% versus 25.9%. The peer-reviewed publication and the company's later annual filing report approximately 58% and 52% versus 20%, and 33% and 36% versus 28%.

Altimmune's early topline release and the later peer-reviewed paper report slightly different percentages. The public documents do not explain the reconciliation in enough detail to assign a cause. We publish the peer-reviewed figures, because a journal's reviewed analysis outranks a press release. The conclusion is identical either way: the MASH-clearing goal was met and the scarring goal was missed.

This is also exactly why the five questions earlier in this page exist. If a page gives you a percentage without telling you which analysis it came from, you can't check it.

What we could not confirm

A public trial-registry record for PERFORMA, as of August 12, 2026.
A peer-reviewed publication of the full 48-week IMPACT results. Those figures remain company-reported here.

Update log

Update log
Date	What changed
August 12, 2026	Page published. Added Phase 3 enrollment opening, the two-cohort trial design and step-up dosing, RESTORE enrollment completion, the current obesity-program status, and the July 2026 alcohol use disorder result. Rechecked the expanded-access policy, FDA compounding routes, FDA-approved MASH options, internal links, and Ro pricing.

We'll add a line here every time we re-verify. If the top of this page says a date and this log doesn't, hold us to it.

Frequently asked questions

Is pemvidutide the same as Ozempic?

No. Ozempic contains semaglutide and works on one receptor, GLP-1. Pemvidutide is an investigational molecule designed to work on two — GLP-1 and glucagon — in a 1:1 balance. Ozempic is approved. Pemvidutide is not.

Is pemvidutide a GLP-1 drug?

Partly. It's a dual glucagon/GLP-1 receptor agonist. Calling it "a GLP-1" leaves out half its design, and the glucagon half is the reason it's being developed for liver disease.

What was the biggest pemvidutide weight-loss result?

15.6% average weight loss at 48 weeks on the 2.4 mg dose in the MOMENTUM Phase 2 obesity trial, in adults with obesity or excess weight and no diabetes. About 32% of that group lost 20% or more.

Why was weight loss lower in the liver trial?

Different patients and lower doses. The liver trial used 1.2 and 1.8 mg — it never tested 2.4 mg. At 48 weeks, the 1.8 mg group averaged 7.5%.

Did pemvidutide reverse fatty liver?

It produced large drops in liver fat — up to about 76% relative reduction in one small study. But "reversed fatty liver" is too broad. Liver fat, MASH activity, scarring, and long-term outcomes are four separate measurements.

Did pemvidutide reverse liver scarring?

Not conclusively. The 24-week biopsy goal for scarring improvement was not statistically significant. Blood tests and scans at 48 weeks improved, but those aren't a second biopsy.

Did pemvidutide clear MASH?

In the Phase 2b trial, 52% to 58% of treated participants met the study's definition of MASH clearing without worse scarring at 24 weeks, versus 20% on placebo. That's a trial endpoint, not a cure.

Is pemvidutide FDA approved?

No. It is investigational, with Fast Track and Breakthrough Therapy designations for MASH. Neither is approval.

Can a doctor prescribe pemvidutide?

No. There's no approved product to prescribe. Access is limited to people enrolled in Altimmune's trials.

Is pemvidutide in Phase 3?

Yes, for MASH. The PERFORMA trial opened enrollment on August 3, 2026, with about 1,790 participants planned.

When will Phase 3 results come out?

The company expects a 52-week readout in 2029. Full approval would depend on liver-event data tracked to roughly 60 months in the trial.

Can I join a pemvidutide trial?

Possibly, if a site is recruiting near you and you meet the protocol. Altimmune says PERFORMA is for adults with MASH and confirmed F2–F3 fibrosis. Check Altimmune's official trials page for enrollment information. Expect a demanding screening process.

Is "research grade" pemvidutide sold online the same as the trial drug?

There's no basis to assume so. A label doesn't establish identity, purity, dose accuracy, or sterility, and lab suppliers state plainly that these products are not for human use.

Can pemvidutide be compounded?

We found no lawful U.S. route to compound it for human use. We found no applicable USP or NF monograph or shortage route. Pemvidutide is not a component of an approved drug and does not appear by name on FDA's current 503A or 503B bulk-substance lists or interim categories.

Is pemvidutide better than Wegovy or Zepbound?

Unknown, and not established by any head-to-head trial. Wegovy is approved for MASH with moderate-to-advanced scarring; pemvidutide is not approved for anything.

Does pemvidutide help with alcohol cravings?

The July 2026 topline report showed fewer heavy-drinking days, more alcohol-free days, and lower PEth blood-marker levels. It did not report a separate craving endpoint. That is a different development program at the 2.4 mg dose, and pemvidutide is not approved for alcohol use disorder.

Was it studied in people with diabetes?

Yes in the liver trial — 43% of IMPACT participants had type 2 diabetes. The obesity trial excluded diabetes.

What is ALT-801?

The earlier development name for pemvidutide. You'll also see SP-1373 in older documents.

Does it protect muscle during weight loss?

In a 50-person imaging substudy of the obesity trial, about 21.9% of the weight lost was lean mass and 78.1% was fat. That's a small substudy, not a proven advantage over other medications.

The bottom line

Pemvidutide's weight-loss and liver results are real, and they came from different trials at different doses in different people. The 15.6% figure is an obesity-trial number at a dose the liver trial never tested — and roughly one in five people at that dose stopped treatment after an adverse event. The liver numbers are strong on fat, inflammation, and scan-based markers, and short of the mark on the one biopsy measure that matters most for scarring.

It isn't approved. It isn't for sale. The only registrational trial running is for liver disease, not weight loss, and its first real answer arrives in 2029.

That means the useful move today isn't waiting. It's finding out what your liver records actually say, and what you can get with them.

Still not sure which GLP-1 program is right for you? Take our free matching quiz — about 2 minutes, no signup.

This page is educational and is not medical advice. Pemvidutide is investigational; its safety and effectiveness have not been established. Talk to a licensed clinician about your own liver results and treatment options. Individual results vary.