Evidence Grade A — Regulatory approved. 192 published studies. 25 registered clinical trials.
Medically reviewed by a licensed medical professional
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Setmelanotide (sold as Imcivree) is a precision medicine treatment for severe obesity caused by specific rare genetic mutations that break the brain's hunger control system. People with these mutations experience constant, insatiable hunger from early childhood. Setmelanotide is the first drug that directly fixes the broken signalling pathway — but only in patients whose genes have been tested and confirmed to carry an eligible mutation.
Setmelanotide is also known by these brand and alternate names:
192 published studies: 112 human, 10 animal, 11 in-vitro, 79 reviews
Setmelanotide is marketed as Imcivree (Rhythm Pharmaceuticals; approved November 2020 for POMC, PCSK1, or LEPR deficiency; June 2022 for Bardet-Biedl syndrome; December 2024 expanded to patients aged 2 years and older). Genetic testing confirming an eligible mutation is required before treatment.
In patients with POMC or PCSK1 deficiency, approximately 80% achieved at least 10% weight loss in clinical trials. In Bardet-Biedl syndrome, 32.3% achieved the same threshold. The most common side effects are injection-site reactions and skin darkening (due to the melanocortin pathway's connection to pigmentation). Setmelanotide exemplifies precision medicine — it is highly effective in the specific genetic populations it targets but is not indicated for common obesity.
In a healthy brain, a pathway runs from the hormone leptin through a series of intermediary signals (POMC, PCSK1) to the melanocortin-4 receptor (MC4R), which controls feelings of fullness. When any link in this chain is broken by a genetic mutation, the MC4R never receives the 'you are full' signal, resulting in constant, insatiable hunger and severe obesity from early childhood. Setmelanotide bypasses the broken links by directly activating the MC4R, restoring the satiety signal that was genetically absent.
In patients with POMC or PCSK1 gene deficiencies, approximately 80% achieved at least 10% weight loss, with average losses of 23% — remarkable results in a population that had no previous treatment option. In Bardet-Biedl syndrome (a broader genetic condition), 32% achieved the same threshold. The expanding list of approved genetic conditions shows the manufacturer's strategy to widen the eligible population. Setmelanotide exemplifies precision medicine: it is highly effective in the specific genetic populations it targets but is not indicated or expected to work for common obesity. Side effects include injection-site reactions, skin darkening (because the melanocortin pathway also controls pigmentation), and monitoring for depression and suicidal thoughts is required. The eligible patient population is very small — approximately 2,500–3,000 diagnosed patients in the US across all approved indications.
PeptideTrace tracks 25 registered clinical trials for Setmelanotide sourced from ClinicalTrials.gov.
An Expanded Access Protocol for Setmelanotide for Treatment of Bardet-Biedl Syndrome (BBS)
Setmelanotide to Treat Obesity in a Patient With Pseudohypoparathyroidism Type 1a (PHP1a)
A Trial of Setmelanotide in Patients With Congenital Hypothalamic Obesity (Sub-study of NCT05774756)
A Study of Setmelanotide in Patients With Prader-Willi Syndrome
Open-Label Extension Study of Setmelanotide
FDA ORIG 1
EMA Marketing Authorisation
FDA SUPPL 1
Health Canada Market Authorisation
FDA SUPPL 5
FDA SUPPL 7
FDA SUPPL 8
Setmelanotide is a cyclic 8-amino-acid peptide that acts as a selective melanocortin-4 receptor (MC4R) agonist. It is a precision medicine therapy designed to treat obesity caused by specific genetic defects in the leptin-melanocortin satiety signaling pathway.
Setmelanotide directly activates MC4R, restoring the downstream satiety signaling that is lost when upstream components (POMC, PCSK1, LEPR) are genetically deficient. In patients with these rare monogenic obesity disorders, the leptin-melanocortin pathway is disrupted at various upstream points, but MC4R itself remains functional. Setmelanotide bypasses the defect by directly activating the intact downstream receptor. Unlike bremelanotide, setmelanotide does not cause tachycardia or hypertension (a critical differentiator for a chronic obesity medication).
Setmelanotide is marketed as Imcivree (Rhythm Pharmaceuticals). Approved November 25, 2020 for obesity due to POMC, PCSK1, or LEPR deficiency; June 2022 for Bardet-Biedl syndrome; December 20, 2024 expanded to patients aged ≥2 years. Requires genetic testing confirming eligible mutations. POMC/PCSK1 trial (N=10): 80% achieved ≥10% weight loss; mean −23.1%. LEPR trial (N=11): 45.5% achieved ≥10% loss; mean −9.7%. BBS trial (N=32): 32.3% achieved ≥10% loss. Hyperpigmentation occurred in 51–61% (MC1R cross-activation).
Semaglutide is one of the most extensively studied peptide medications available today, with clinical trial data spanning over 50,000 patients. It is sold as Ozempic for type 2 diabetes (approved 2017), Rybelsus as an oral tablet for diabetes (approved 2019), and Wegovy for weight management (approved 2021). Wegovy has since received additional approvals for reducing heart attack and stroke risk, for use in adolescents aged 12 and older, and for liver disease related to obesity. In clinical trials, patients taking Wegovy lost an average of 14.9% of their body weight over 68 weeks, and the SELECT trial demonstrated a 20% reduction in major cardiovascular events such as heart attack and stroke. Research is now exploring its potential in early Alzheimer's disease. The main side effects are gastrointestinal, particularly nausea, and a key limitation is that most weight tends to return after stopping treatment.
Bimagrumab is in Phase II/III development (not yet approved). A Phase II trial (75 patients with type 2 diabetes and obesity) showed 20.5% fat mass reduction with 3.6% lean mass increase — essentially reshaping body composition without net appetite suppression. The BELIEVE Phase IIb trial (507 patients) showed that bimagrumab plus semaglutide achieved 22% weight loss with the weight lost being 88% fat — significantly better body composition than semaglutide alone. Bimagrumab is not a peptide. Its strategic significance is as a combination partner to address the muscle loss problem inherent in weight loss with current obesity drugs. Eli Lilly's acquisition positions it alongside tirzepatide.
Pemvidutide is in Phase II/III development (not yet approved). In the MOMENTUM Phase II trial (391 patients, 48 weeks), the 2.4 mg dose achieved 15.6% weight loss. Body composition analysis showed 78% of weight lost was fat mass, with only 22% lean mass — a favourable ratio. A Phase IIb MASH trial (212 patients) showed MASH resolution in up to 75% of patients at the highest dose. Pemvidutide's balanced receptor profile and no-titration dosing regimen represent potential practical advantages. The high rate of MASH resolution in Phase II positions it as a candidate for liver disease indications alongside obesity.
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