Pegozafermin dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Pegozafermin is a long-acting copy of FGF21, a liver hormone, given every week or two. Roche now owns it, and it is in two large final-stage studies in fatty liver disease.
Evidence grade for Pegozafermin: Limited. The rule: people have taken it in a published study, but fewer than 100 of them. The sum on this page: 1 completed trial, none stating how many people. A grade counts how much has been done to people, not whether it works.
- People given it
- 0
- Human studies
- 1
- Found nothing
- 0
Dose
No human dose established
Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose.
1 completed trial, 0 people given it
2 effects reported, 1 unwanted, 1 wanted, by people using it, not a trial
Goal pages: Fat loss and metabolism, Gut health
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
Pegozafermin is a shot that copies FGF21, a liver hormone. It is given every week or two. Roche owns it now. It is being tested for fatty liver disease. It is not approved.
What people take it for
- Reversing liver scarring from fatty liver disease.
- Lower blood fats.
What studies in people showed
The main study had 219 people with moderate or severe scarring from fatty liver disease. After 24 weeks, scarring improved in 22 to 27 percent of people on the drug. It improved in 7 percent on a dummy shot. Nausea and diarrhoea were the most common side effects. The maker paid for the study. Two large final-stage studies are running.
What people report
Reports, not study results
The good
- In the study on this page, liver scarring improved in about a quarter of people on the drug.
The bad
- Nausea and diarrhoea were the most common side effects in the study on this page.
Where these come from: Both lines are from the study on this page. We have not collected forum or user reports for this drug yet.
My bottom line
Promising for a liver problem most people do not know they have. Blood work first. This is still in testing.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals Pegozafermin has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Liver fat and liver healthno headcount stated · 1 study
35 of the 36 indexed goals have no study of any kind behind Pegozafermin
No study in people, animals or cells on this page reports a result for these. That does not prove Pegozafermin does nothing for them. It does mean anything you have heard about Pegozafermin and one of these did not come from a study cited here.
Show full evidence
What is Pegozafermin?
Pegozafermin is a long-acting copy of FGF21, a liver hormone, given every week or two. Roche now owns it, and it is in two large final-stage studies in fatty liver disease.
Pegozafermin was made by 89bio, which Roche bought in 2025. It copies FGF21, a liver hormone. In the mid-stage ENLIVEN study, 219 people with moderate or severe scarring from fatty liver disease took it or a dummy shot for 24 weeks. Scarring improved in 22 to 27 percent on the drug, against 7 percent on the dummy. Two large final-stage studies are running. ENLIGHTEN-Fibrosis covers moderate to severe scarring, and ENLIGHTEN-Cirrhosis covers cirrhosis. Both judge the drug on a liver sample after 52 weeks. Roche now holds an FGF21 drug, a GLP-1 and GIP drug called enicepatide, and an amylin partnership.
How does Pegozafermin work?
It copies FGF21 and lasts a long time. It lowers liver fat and scarring and improves blood fats.
The evidence, in charts
Fig. 1a · how many people
2studies in people cited, but none says how many people took part
number of people not stated
We do not draw a total, because none of the studies in people on this page gives one. Read the sources below for what each study measured.
We read the number of people from the source lines on this page. Where a line gives no number, we count nothing for it. We do not guess.
Fig. 1b · evidence mix
All 2 sources here are studies in people.
- Study in people · done in people2100%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
Sources here come from just two years, 2023 and 2024.
Too few different years on this page to draw a timeline.
Fig. 3 · legal status at a glance
US
Not approved
UK
Not approved
AU
Not approved
CA
Not approved
Not approved in any of the four countries shown. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 4 · how much does what
Nobody has tested different amounts in people
This chart would show how the effect changes as the amount goes up. For this compound, nobody has measured that in people. So we leave it empty. We will not borrow an animal chart and pretend it works the same in people.
Fig. 5 · what the molecule is
- Kind of compound
- Biologic
- Molecule weight
- No single molecular weight: a glycoPEGylated FGF21 analog whose PEG chain length varies (KEGG lists the protein plus an indefinite PEG term)
- Half-life
- Stated in words, not a numbersee the exact wording below
- Chain length
- None on file
No amino acid sequence is on file for Pegozafermin, so none is drawn rather than guessed from a name.
The studies we cite
- Study in people2023Randomized, Controlled Trial of the FGF21 Analogue Pegozafermin in NASH
Liver scarring improved on the drug in a mid-stage study. 219 people with moderate or severe scarring from fatty liver disease got pegozafermin or a dummy shot for 24 weeks. Scarring improved in 22 to 27 percent of those on the drug, against 7 percent on the dummy. Nausea and diarrhoea were the most common side effects. Twenty four weeks is a short window for liver scarring, and 89bio, which made the drug, paid for the study.
Fibrosis improvement without worsening of MASH at 24 weeks.
- Study in people202489bio initiates Phase 3 ENLIGHTEN-Fibrosis
This trial is running and has published nothing. It is the large final-stage test of pegozafermin, judged on what a liver biopsy shows after a year. A biopsy result is a stronger measure than the blood markers and scans most liver trials lean on. No results have been reported.
52-week histology co-primary endpoints.
Common questions
Has Pegozafermin been tested in people?
Yes. 0 people given it across 1 completed trial cited here, 0 of which found nothing. Pegozafermin is a long-acting copy of FGF21, a liver hormone, given every week or two. Roche now owns it, and it is in two large final-stage studies in fatty liver disease.
What is the Pegozafermin dosage?
No human dose established. Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose. 1 completed trial, 0 people given it
Is Pegozafermin FDA-approved?
Investigational; in final-stage studies
How does pegozafermin differ from efruxifermin?
Both copy FGF21. They use different tricks to last longer, a PEG chain versus part of an antibody, and they have different dose schedules. Neither has final-stage results yet.