Metreleptin vs Setmelanotide
Written by Aaron CuhaReviewed Sep 2026
The short answer
Two approved drugs for rare metabolic diseases that are easy to mix up, because both work on the pathway that links fat stores to appetite. One replaces a missing hormone. The other switches on a target further down the same chain. Which one fits depends entirely on a person's genes.
- Metreleptin people
- 0
- Metreleptin nulls
- 0
- Setmelanotide people
- 38
- Setmelanotide nulls
- 0
Dose
No human dose established
No published study on this page has given this compound to people and reported a result.
1 human study where nobody was given it
Dose
Approved medicine. No human dose established for unlabelled uses
Labeled amounts sit on the prescribing information. This page records what trials measured, not a personal dose.
FDA-approved (Imcivree) for certain rare genetic causes of obesity
First-hand reports are counted on each profile and never added together. This page sets two published records side by side. It does not pick a winner.
Column A
MetreleptinMetreleptin (Myalept), recombinant human leptin analogue
Life-changing in people who make almost no leptin, and useless for ordinary obesity. The clearest case on this site of a hormone that only works when you are short of it.
Column B
SetmelanotideSetmelanotide (MC4R agonist)
An FDA-approved shot for rare genetic types of obesity, where a broken gene stops the brain from feeling full.
Side by side, on the facts we can check
| What we compare | Metreleptin | Setmelanotide |
|---|---|---|
| Category | Hormone | Melanocortin |
| FDA status | FDA-approved as Myalept for problems caused by too little leptin in generalised lipodystrophy, a rare condition where the body has almost no fat. It carries a boxed warning, the FDA's strongest, for two risks. The body can make antibodies that block the drug, and it can raise the risk of T-cell lymphoma, a blood cancer. It is only supplied through a restricted program. Not approved for obesity or partial lipodystrophy. | FDA-approved (Imcivree) for certain rare genetic causes of obesity |
| Half-life | Roughly three to four hours after subcutaneous injection, which is why it is dosed daily. | ~11 hours |
| Molecular weight | 16.2 kDa. A 147-amino-acid recombinant protein. | 1,117.3 Da |
| How it works | Metreleptin is a lab-made copy of human leptin, with one extra amino acid (methionine) added. Fat cells release leptin in line with how much fat you carry. It acts on the brain's hunger center (the hypothalamus). It turns down the nerve cells that drive hunger (NPY and AgRP) and turns up the ones that curb it (POMC). It also tells the systems for reproduction, thyroid and immunity that there is enough food. With no leptin, all those signals read as starving, no matter how much energy the body has stored. That is why replacing it does so much. In ordinary obesity, leptin is already high and the brain has stopped responding, so adding more changes little. | It switches on MC4R, the brain's fullness switch. That brings back the fullness signal that the broken genes shut off. |
| Studies in people | 1 | 2 |
| Evidence | Preliminary: 1 human study where nobody was given it | Limited: 1 completed trial, 38 people given it |
| Legal status, US | FDA-approved, prescription only | FDA-approved, prescription only |
Frequently asked questions
What is the difference between Metreleptin and Setmelanotide?
Metreleptin: Life-changing in people who make almost no leptin, and useless for ordinary obesity. The clearest case on this site of a hormone that only works when you are short of it. Setmelanotide: An FDA-approved shot for rare genetic types of obesity, where a broken gene stops the brain from feeling full.
Which has stronger research evidence, Metreleptin or Setmelanotide?
Each compound gets a band worked out from facts we counted, with the math shown. Metreleptin is Preliminary (1 human study where nobody was given it). Setmelanotide is Limited (1 completed trial, 38 people given it). That counts how much has been done in people. It does not rate whether either one works, and neither one is called the winner.
Are Metreleptin and Setmelanotide FDA-approved?
Metreleptin: FDA-approved as Myalept for problems caused by too little leptin in generalised lipodystrophy, a rare condition where the body has almost no fat. It carries a boxed warning, the FDA's strongest, for two risks. The body can make antibodies that block the drug, and it can raise the risk of T-cell lymphoma, a blood cancer. It is only supplied through a restricted program. Not approved for obesity or partial lipodystrophy.. Setmelanotide: FDA-approved (Imcivree) for certain rare genetic causes of obesity.
Reviewed Sep 2026. This page puts two published records side by side. It is for learning, and it is not medical advice. When this site shows a dose, it is the dose a trial or a clinic actually used, or what people say they did, with the source attached. None of it tells you what to take.