Bivamelagon dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Bivamelagon is a pill meant to turn down appetite. It works on the same brain switch, called MC4R, as setmelanotide, which is a shot. A 28 person study in people whose obesity came from brain damage finished in February 2026. No results have been posted. Nothing on this drug has been published in a science journal.
Evidence grade for Bivamelagon: 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
1 effects reported, 1 unwanted, by people using it, not a trial
Goal pages: Fat loss and metabolism
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.
Bivamelagon is a pill meant to turn down hunger. It works on the same brain switch as setmelanotide, which is a daily shot. The switch is called MC4R. It is being tested in people whose obesity came from damage to the part of the brain that runs hunger. It is not approved anywhere.
What people take it for
- Weight loss from a pill instead of a shot.
- Hunger that will not switch off after brain damage from a tumour or its treatment.
What studies in people showed
At least 140 people have taken it, and nobody outside the company knows what happened. A first safety study had 112 adults carrying extra weight. It ended in 2022 with no results shared. A study in 28 people with brain related obesity ended in February 2026. No results have been posted. A search of medical papers finds zero on this drug. Any weight loss number you see comes from company slides. In monkeys, a different pill that also hits a related switch caused weight loss. That is not this drug.
What people report
Reports, not study results
The good
- We have not collected user reports on this one yet.
The bad
- No side effects have been published. The shot in the same family, setmelanotide, often darkens the skin. Nobody knows yet if this pill does too.
Where these come from: There are no user reports. The side effect note comes from the setmelanotide background on this page, not from a study of this drug.
My bottom line
My opinion: there is nothing here to judge yet. No published results means no reason to chase it. If you are fighting your weight, start with blood work, protein and lifting, and let this one report first.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Animal and lab work, not yet tested in people
Real results, but from animals or cells, not people. What works in a mouse often does not work the same way in a person. Nobody can patent this, so nobody would ever earn back the cost of a study in people. That is usually why there is none. The record on this one is set out below.
- Losing weight1 animal or lab study
35 of the 36 indexed goals have no study of any kind behind Bivamelagon
No study in people, animals or cells on this page reports a result for these. That does not prove Bivamelagon does nothing for them. It does mean anything you have heard about Bivamelagon and one of these did not come from a study cited here.
Show full evidence
What is Bivamelagon?
Bivamelagon is a pill meant to turn down appetite. It works on the same brain switch, called MC4R, as setmelanotide, which is a shot. A 28 person study in people whose obesity came from brain damage finished in February 2026. No results have been posted. Nothing on this drug has been published in a science journal.
Bivamelagon is a pill meant to turn down appetite. It works on the same brain switch as setmelanotide, a daily shot. That switch is called the melanocortin-4 receptor, or MC4R. LG Chem found it under the code LB54640. Rhythm Pharmaceuticals now develops it for hypothalamic obesity. That is weight gain after a tumour, or its treatment, damages the hypothalamus, the part of the brain that runs hunger. The point is simple: a drug for this switch that you swallow instead of inject.
Nothing measured in people has been published yet. A first safety study in 112 healthy adults carrying extra weight (NCT06040372, LG Chem) finished in 2022. A study in 28 people with hypothalamic obesity (NCT06046443, Rhythm) finished in February 2026. As of September 2026 no results are posted. A follow on study (NCT07156578) is taking people by invitation and should finish in 2028. A four person study in obesity caused by a gene fault (NCT06041841) has an unknown status. A search of PubMed, the main index of medical papers, for bivamelagon or LB54640 finds zero papers. Any weight loss number you see comes from company slides. Nobody can check it against a paper or a posted result.
In animals, the background is about the drug family, not this drug. A 2026 study in obese male monkeys tested a different pill that hits both MC3R and MC4R. The monkeys lost weight. The authors say drugs that hit MC4R alone have done poorly in common obesity. Bivamelagon is not approved anywhere, and no regulator has reviewed it.
How does Bivamelagon work?
In people, drugs in this family turn down appetite by switching on MC4R in the brain. Some rare gene faults, in POMC, PCSK1 and LEPR, break the chain of signals that leads to this switch. Setmelanotide works by flipping the switch anyway. The company says bivamelagon hits MC4R and not much else, and that it works as a pill. No lab data, blood level data or dose data on bivamelagon has been published. So this explanation comes from the drug family and the company, not from data on this drug. In monkeys, a 2026 study of a different pill found that hitting MC3R as well as MC4R caused more weight loss than MC4R alone. That tells you about the appetite system in monkeys. It says nothing direct about bivamelagon.
What have studies in people found about Bivamelagon?
At least 140 people have taken bivamelagon across two studies. Nothing from either has been published or posted. No human data on this drug has been checked by outside scientists.
- NCT06040372: 112 healthy adults carrying extra weight, a first safety study run by LG Chem. Finished March 2022. No results posted, no paper.
- NCT06046443: 28 people with hypothalamic obesity, a mid-stage study run by Rhythm Pharmaceuticals. Finished 9 February 2026. No results posted as of September 2026.
- NCT07156578: a follow on study in hypothalamic obesity. About 25 people expected, by invitation only. Due to finish April 2028.
- NCT06041841: a study in obesity caused by a gene fault. About 4 people expected. Status unknown.
- A PubMed search for bivamelagon or LB54640 in September 2026 found zero papers.
What this does not tell you: Nothing on this page tells you if bivamelagon lowers weight. It does not say by how much, in whom, or with what side effects. None of that has been shared outside company materials. Hypothalamic obesity is rare, and it works differently from common obesity. So even a good result there would not carry over to general weight loss. Setmelanotide, the shot in the same family, often darkens the skin and causes reactions where the needle goes in. Nobody knows yet if a pill in this family darkens skin too.
The state of the research
This is a normal early drug programme, and the record looks like one. There are registry entries. There is a finished study whose results belong to the company until it chooses to share them. There is no outside data. Rhythm has a business reason to want a pill. Setmelanotide is its approved shot for the same switch and the same rare kinds of obesity. A pill would extend that business. That cuts both ways. The company will run the studies, and the company decides when and how results come out.
Bivamelagon shows up in peptide catalogues because of the switch it hits, not because of what it is. Setmelanotide, bremelanotide and the melanotans are peptides. Bivamelagon works on the same switch and gets listed next to them. There is no legal supply outside the studies. Nothing sold under the name can be checked against a published recipe, because none exists.
The evidence, in charts
Fig. 1a · how many people
4studies 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
4 of 5 sources here are studies in people. The rest is not.
- Study in people · done in people480%
- Animal study · done in animals120%
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
The studies cover 5 different years, 2020 to 2026, counted from the list of sources on this page.
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
- Small molecule
- Molecule weight
- Not on file
- Half-life
- None on file
- Chain length
- None on file
No amino acid sequence is on file for Bivamelagon, which is expected: a small molecule is not built from amino acids.
The studies we cite
- Study in people2024A Study to Assess Efficacy and Safety of LB54640 in Patients With Hypothalamic Obesity (NCT06046443)
This trial is over and nobody has been told what happened. Twenty eight people whose obesity comes from damage to the hypothalamus took part. It ran from July 2024 and finished in February 2026. As of September 2026 no results have been posted and no paper has been found. The record shows a completed trial and an empty results section. That is all anyone can say about it. The drug company paid for the study.
Phase 2, 28 participants with hypothalamic obesity, started July 2024, primary completion 9 February 2026. Status completed; no results posted as of September 2026. Sponsor funded.
- Study in people2025A Long-Term Study of Bivamelagon in Participants With Hypothalamic Obesity (NCT07156578)
This study is still running and has reported nothing. It is an extension for people who were already in an earlier trial of this drug. About twenty five are expected. Everyone knows they are getting the drug and there is no comparison group. Enrolment is by invitation only and began in November 2025. The first results are not due until 2028. The record shows a study in progress. The drug company is paying for it.
Open label extension, phase 2, estimated 25 participants, enrolling by invitation since November 2025 with primary completion projected for April 2028. Sponsor funded.
- Study in people2020A First in Human Study to Assess the Safety, Tolerability of LB54640 in Healthy Overweight and Obese Subjects (NCT06040372)
A first safety study in healthy people that has never been reported. One hundred and twelve adults carrying extra weight took part. LG Chem ran it from March 2020 to March 2022 and marked it completed. No results were posted and no paper has been found. Nobody outside the company knows what it showed. This is what the record shows, not a judgement about the drug.
Phase 1, 112 healthy adults with overweight or obesity, run by LG Chem from March 2020 to March 2022. Completed; no results posted and no publication located.
- Study in people2023A Phase 2 Study to Assess Efficacy and Safety of LB54640 in Patients With Genetic Obesity (NCT06041841)
This record has been left to go stale. It was set up as a study in people whose obesity comes from a gene fault, and it expected only four of them. The sponsor has not updated the entry since, so its status is listed as unknown. Nobody knows whether it ran, stopped or finished. There are no results because there is no report. Four people would not have settled anything either way.
Estimated 4 participants with genetic obesity; the record has not been updated and is listed with an unknown status.
- Animal study2026Dual activation of MC3R and MC4R drives weight loss and reduces food intake in male primates with obesity
In monkeys. This study is not about bivamelagon. Obese male monkeys got a different pill that hits both MC3R and MC4R, and they lost weight. The authors say drugs that hit MC4R alone have done poorly in common obesity. The senior author owns a stake in the company making that pill.
Class background only, not about bivamelagon. In male nonhuman primates with diet induced obesity, an oral dual MC3R and MC4R agonist (710GO) produced weight loss, and the authors note that selective MC4R agonists have had limited clinical success in general obesity. The senior author holds equity in the company developing the compound.
Common questions
Has Bivamelagon been tested in people?
Yes. 0 people given it across 1 completed trial cited here, 0 of which found nothing. Bivamelagon is a pill meant to turn down appetite. It works on the same brain switch, called MC4R, as setmelanotide, which is a shot. A 28 person study in people whose obesity came from brain damage finished in February 2026. No results have been posted. Nothing on this drug has been published in a science journal.
What is the Bivamelagon 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 Bivamelagon FDA-approved?
Not FDA approved. Investigational. A mid-stage study in hypothalamic obesity, which comes from damage to the part of the brain that controls hunger, is finished with no results posted. A follow-on study, where everyone knows they are getting the drug, is signing people up (September 2026).
Has bivamelagon produced weight loss in a trial?
The 28 person study in hypothalamic obesity finished in February 2026, so it has been run. As of September 2026 the results are not posted and not published. Any percentage you see comes from company slides. Nobody outside the company can check it.
How is it different from setmelanotide?
Both work on the MC4R appetite switch in the brain. Setmelanotide is a ring shaped peptide given as a daily shot. It is approved for obesity caused by certain gene faults and for Bardet-Biedl syndrome. Bivamelagon is a pill that works on the same switch. Nobody has reported yet if it works as well, or if it darkens the skin the way setmelanotide can.
Is bivamelagon a peptide?
The company calls it a pill that switches on MC4R. Its structure has not been published in a science journal. It shows up in peptide catalogues because of the switch it hits. The peptide drugs setmelanotide and bremelanotide hit that switch too.
Can I buy bivamelagon?
It is a test drug with no approval in any country. There is no published recipe for it. Anything sold under the name cannot be checked against anything.