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Comparison

Semaglutide vs Setmelanotide

Semaglutide is GLP-1 & incretins; Setmelanotide is melanocortins. They are compared here because they are frequently considered against each other, not because they act alike.

Semaglutide Setmelanotide
Class GLP-1 & incretins Melanocortins
Evidence Regulator approved Regulator approved
Human trials ~90 ~10
Half-life ~7 days ~11 hours
Reported range 250 mcg - 2.4 mg 1-3 mg
Frequency Once weekly, titrated over 16+ weeks Once daily
Routes Subcutaneous, Oral Subcutaneous
FDA approved Yes Yes
Research use only No No
Banned in sport No No
Studied for Type 2 diabetes, Chronic weight management, Cardiovascular risk reduction POMC, PCSK1 and LEPR deficiency obesity, Bardet-Biedl syndrome
Reported side effects Nausea, Vomiting, Diarrhoea, Constipation, Abdominal pain, Injection-site reactions Injection-site reactions, Skin hyperpigmentation, Nausea, Spontaneous penile erection, Depression

Semaglutide

Semaglutide is a GLP-1 analog with roughly 94% homology to native GLP-1, modified by substituting alpha-aminoisobutyric acid at position 8 to resist DPP-4 cleavage and by attaching a C18 fatty diacid chain that binds albumin. Together these give a half-life of about a week, allowing once-weekly dosing. It lowers blood glucose through glucose-dependent insulin secretion and glucagon suppression, slows gastric emptying, and acts on hypothalamic appetite centres to reduce energy intake. The STEP trial programme reported mean weight reductions near 15% of body weight at 68 weeks on 2.4 mg weekly.

Setmelanotide

Setmelanotide is a cyclic peptide agonist selective for the melanocortin-4 receptor, the terminal node of the leptin-melanocortin pathway that regulates hunger and energy balance. In patients whose obesity stems from defects upstream of MC4R, such as POMC, PCSK1 or LEPR deficiency, it restores signalling through the intact receptor and produces substantial weight loss and reduced hyperphagia. It is ineffective where the MC4R itself is fully non-functional, which is why genetic confirmation gates its use.

Semaglutide vs Setmelanotide: common questions

What is the difference between Semaglutide and Setmelanotide?

Semaglutide is GLP-1 & incretins and Setmelanotide is melanocortins, so they act on different pathways. Semaglutide: A long-acting GLP-1 receptor agonist and the compound that reset expectations for pharmacological weight loss. Setmelanotide: A selective MC4R agonist approved for rare genetic obesity syndromes, and a genuine precision medicine.

Which has stronger evidence, Semaglutide or Setmelanotide?

They sit at the same evidence level: regulator approved. Semaglutide has about 90 human studies and Setmelanotide about 10.

Are Semaglutide and Setmelanotide FDA approved?

Both are FDA approved. Semaglutide: Type 2 diabetes mellitus (Ozempic, Rybelsus); Chronic weight management (Wegovy); Cardiovascular risk reduction in established CVD with overweight or obesity; Reducing the risk of kidney disease progression and cardiovascular death in adults with type 2 diabetes and chronic kidney disease (Ozempic, January 2025); Noncirrhotic MASH with moderate to advanced liver fibrosis in adults (Wegovy, accelerated approval August 2025). Setmelanotide: Obesity due to POMC, PCSK1 or LEPR deficiency; Bardet-Biedl syndrome (Imcivree).

References

Regulatory and primary sources

  1. PubChem compound record (CID 56843331) ↗ · structure, identifiers, synonyms
  2. DailyMed: FDA-approved labeling for Semaglutide ↗ · indications, dosing, warnings as approved
  3. FDA Drugs@FDA database ↗ · approval history
  4. CAS Registry Number 910463-68-2 ↗ · chemical identity
  5. PubChem compound record (CID 11993702) ↗ · structure, identifiers, synonyms
  6. DailyMed: FDA-approved labeling for Setmelanotide ↗ · indications, dosing, warnings as approved
  7. FDA Drugs@FDA database ↗ · approval history
  8. CAS Registry Number 920014-72-8 ↗ · chemical identity

Published literature

  1. Wilding JPH, Batterham RL, Davies M, et al.. Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension.Diabetes Obes Metab 2022.PubMed 35441470 · doi:10.1111/dom.14725
  2. Rubino DM, Greenway FL, Khalid U, et al.. Effect of Weekly Subcutaneous Semaglutide vs Daily Liraglutide on Body Weight in Adults With Overweight or Obesity Without Diabetes: The STEP 8 Randomized Clinical Trial.JAMA 2022.PubMed 35015037 · doi:10.1001/jama.2021.23619
  3. Wilding JPH, Batterham RL, Calanna S, et al.. Once-Weekly Semaglutide in Adults with Overweight or Obesity.N Engl J Med 2021.PubMed 33567185 · doi:10.1056/NEJMoa2032183
  4. Rubino D, Abrahamsson N, Davies M, et al.. Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance in Adults With Overweight or Obesity: The STEP 4 Randomized Clinical Trial.JAMA 2021.PubMed 33755728 · doi:10.1001/jama.2021.3224
  5. Aronne LJ, Horn DB, le Roux CW, et al.. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity.N Engl J Med 2025.PubMed 40353578 · doi:10.1056/NEJMoa2416394
  6. Wharton S, Freitas P, Hjelmesæth J, et al.. Once-weekly semaglutide 7·2 mg in adults with obesity (STEP UP): a randomised, controlled, phase 3b trial.Lancet Diabetes Endocrinol 2025.PubMed 40961952 · doi:10.1016/S2213-8587(25)00226-8
  7. Lincoff AM, Brown-Frandsen K, Colhoun HM, et al.. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes.N Engl J Med 2023.PubMed 37952131 · doi:10.1056/NEJMoa2307563
  8. Frías JP, Davies MJ, Rosenstock J, et al.. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes.N Engl J Med 2021.PubMed 34170647 · doi:10.1056/NEJMoa2107519
  9. Faccioli N, Poitou C, Clément K, et al.. Current Treatments for Patients with Genetic Obesity.J Clin Res Pediatr Endocrinol 2023.PubMed 37191347 · doi:10.4274/jcrpe.galenos.2023.2023-3-2
  10. Markham A. Setmelanotide: First Approval.Drugs 2021.PubMed 33638809 · doi:10.1007/s40265-021-01470-9
  11. Mahmoud R, Kimonis V, Butler MG. Clinical Trials in Prader-Willi Syndrome: A Review.Int J Mol Sci 2023.PubMed 36768472 · doi:10.3390/ijms24032150
  12. Fox CK, Kelly AS, Reilly JL, et al.. Current and future state of pharmacological management of pediatric obesity.Int J Obes (Lond) 2025.PubMed 38321079 · doi:10.1038/s41366-024-01465-y
  13. Shoemaker A. Bardet-Biedl syndrome: A clinical overview focusing on diagnosis, outcomes and best-practice management.Diabetes Obes Metab 2024.PubMed 38383825 · doi:10.1111/dom.15494
  14. Anastasilakis AD, Paccou J, Palermo A, et al.. The effects of anti-obesity medications on bone metabolism: A critical appraisal.Diabetes Obes Metab 2025.PubMed 40555693 · doi:10.1111/dom.16541
  15. Miller JL, van Santen HM, Phillips SA, et al.. Setmelanotide for the Treatment of Acquired Hypothalamic Obesity.N Engl J Med 2026.PubMed 42418774 · doi:10.1056/NEJMoa2512275
  16. Clément K, van den Akker E, Argente J, et al.. Efficacy and safety of setmelanotide, an MC4R agonist, in individuals with severe obesity due to LEPR or POMC deficiency: single-arm, open-label, multicentre, phase 3 trials.Lancet Diabetes Endocrinol 2020.PubMed 33137293 · doi:10.1016/S2213-8587(20)30364-8

Literature retrieved from PubMed on October 16, 2026, favouring human studies and reviews. Numbered markers in the text show which paper supports which statement; uncited entries are background reading.

Read this first This page compares published reference data. It is not medical advice and not a recommendation to use either compound. Several compounds documented on this site are not approved for human use.