Efruxifermin dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Efruxifermin is a weekly shot that copies FGF21, a liver hormone. In people with cirrhosis from fatty liver disease, it missed its main test at 36 weeks. By 96 weeks, scarring improved in 29 percent against 11 percent on a dummy shot. Three large final-stage studies are running.
Evidence grade for Efruxifermin: Moderate. The rule: at least one finished study in people, and at least 100 people who took it. The sum on this page: 1 completed trial, 181 people given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 181
- Human studies
- 1
- Found nothing
- 1
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, 181 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.
Efruxifermin is a weekly shot from Akero that copies FGF21, a liver hormone. It is being made for fatty liver disease, including cirrhosis. It is not approved. It does little for weight.
What people take it for
- Reversing liver scarring from fatty liver disease.
- Lower liver fat.
What studies in people showed
The main study had 181 people with cirrhosis from fatty liver disease. It missed its main test at 36 weeks. Scarring improved in 19 percent on the 50 mg dose, against 13 percent on a dummy shot. By 96 weeks it was 29 percent against 11 percent. A late result like that is a reason to run another study. Three large final-stage studies are running, with the main result due in 2027.
What people report
Reports, not study results
The good
- In the study on this page, scarring improved in more people on the drug by 96 weeks.
The bad
- It missed the main test the study was built to pass at 36 weeks.
- The studies on this page do not list side effects, and we have not collected user reports on this one yet.
Where these come from: Both lines are from the studies on this page. We have not collected forum or user reports for this drug yet.
My bottom line
Fatty liver sneaks up on people. Get your liver numbers on your blood work. This drug is still being tested.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals Efruxifermin 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 health181 people · 1 study · 1 found nothing
35 of the 36 indexed goals have no study of any kind behind Efruxifermin
No study in people, animals or cells on this page reports a result for these. That does not prove Efruxifermin does nothing for them. It does mean anything you have heard about Efruxifermin and one of these did not come from a study cited here.
Show full evidence
What is Efruxifermin?
Efruxifermin is a weekly shot that copies FGF21, a liver hormone. In people with cirrhosis from fatty liver disease, it missed its main test at 36 weeks. By 96 weeks, scarring improved in 29 percent against 11 percent on a dummy shot. Three large final-stage studies are running.
Efruxifermin joins FGF21 to part of an antibody so it lasts longer. FGF21 is a hormone made by the liver that helps the body handle sugar and fat. In the mid-stage SYMMETRY study, 181 people with cirrhosis from fatty liver disease got 28 mg, 50 mg or a dummy shot. Their cirrhosis was confirmed with a liver sample, and their livers were still coping. The drug missed its main test at 36 weeks. Scarring improved, without the liver disease getting worse, in 19 percent on the drug against 13 percent on the dummy. By 96 weeks, the 50 mg group reached 29 percent against 11 percent. Akero is running three large final-stage studies, called SYNCHRONY, and the main liver sample result is expected in 2027.
How does Efruxifermin work?
It turns on the FGF21 receptor for a long time. That lowers liver fat, helps the body use insulin and reduces scarring.
The evidence, in charts
Fig. 1a · how many people
181people, across 1 study in people cited here
| Study | People | Share |
|---|---|---|
| SYMMETRY, New England Journal of Medicine 2025 | 181 | 100% |
The whole total is one study of 181. Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. 1 more study in people gives no headcount and is not counted here. Studies still signing people up are left out, and only studies cited on this page are counted.
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, 2025 and 2026.
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
- 92,108 Da (Fc-FGF21 fusion protein)
- 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 Efruxifermin, so none is drawn rather than guessed from a name.
The studies we cite
- Study in people2026SYNCHRONY Phase 3 program of efruxifermin
Nothing has been published from this program. Akero is running three large final-stage trials of efruxifermin across different degrees of liver scarring, including one that follows what happens to people rather than what a biopsy shows. The main biopsy result is not expected until 2027. Everything known about this drug today comes from earlier and smaller studies.
Three pivotal trials across fibrosis stages.
- Study in people2025Efruxifermin in compensated liver cirrhosis caused by MASH
The trial failed the test it was built to pass, then looked better later. 181 people with liver scarring from fatty liver disease got efruxifermin or a dummy injection. At 36 weeks, when the answer was due, 19% on the 50 mg dose had less scarring against 13% on the dummy, which is not a gap you can lean on. By 96 weeks it was 29% against 11%. A result that arrives after the deadline is a reason to run another trial, not a finding.
SYMMETRY, a Phase 2b trial in 181 patients with biopsy-confirmed compensated cirrhosis. The primary endpoint was missed: at 36 weeks fibrosis improved without worsening MASH in 19% on 50 mg against 13% on placebo. At 96 weeks the figures were 29% on 50 mg against 11% on placebo, a 16 percentage point difference (95% CI 2 to 30).
Common questions
Has Efruxifermin been tested in people?
Yes. 181 people given it across 1 completed trial cited here, 1 of which found nothing. Efruxifermin is a weekly shot that copies FGF21, a liver hormone. In people with cirrhosis from fatty liver disease, it missed its main test at 36 weeks. By 96 weeks, scarring improved in 29 percent against 11 percent on a dummy shot. Three large final-stage studies are running.
What is the Efruxifermin 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, 181 people given it
Is Efruxifermin FDA-approved?
Investigational; in final-stage studies
What is FGF21?
FGF21, short for fibroblast growth factor 21, is a hormone made mainly by the liver when you fast. It helps the body handle fat and sugar. Drugs like efruxifermin copy it and last longer.
Does efruxifermin cause weight loss?
Only a little, if any. It mainly acts on liver fat, scarring and blood fats, not appetite.
Latest reading on Efruxifermin
Blog posts about Efruxifermin, newest first.