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Comparison

Semaglutide vs Tirzepatide

Both are GLP-1 & incretins, so the meaningful differences are in kinetics, evidence and regulatory status.

Semaglutide Tirzepatide
Class GLP-1 & incretins GLP-1 & incretins
Evidence Regulator approved Regulator approved
Human trials ~90 ~60
Half-life ~7 days ~5 days
Reported range 250 mcg - 2.4 mg 2.5-15 mg
Frequency Once weekly, titrated over 16+ weeks Once weekly, titrated over 20+ weeks
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 Type 2 diabetes, Chronic weight management, Obstructive sleep apnoea with obesity
Reported side effects Nausea, Vomiting, Diarrhoea, Constipation, Abdominal pain, Injection-site reactions Nausea, Diarrhoea, Vomiting, Constipation, Dyspepsia, Injection-site reactions

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.

Tirzepatide

Tirzepatide is a 39-amino-acid synthetic peptide that agonises both the glucose-dependent insulinotropic polypeptide receptor and the GLP-1 receptor, a combination sometimes called a twincretin. GIP receptor activity appears to add to the metabolic effect through adipose tissue and central pathways, and may attenuate some GLP-1-related nausea. A C20 fatty diacid moiety confers albumin binding and weekly dosing. The SURMOUNT programme reported mean weight reductions above 20% at the highest dose, and SURMOUNT-5 showed superiority over semaglutide directly.

Semaglutide vs Tirzepatide: common questions

What is the difference between Semaglutide and Tirzepatide?

Both are GLP-1 & incretins. Semaglutide: A long-acting GLP-1 receptor agonist and the compound that reset expectations for pharmacological weight loss. Tirzepatide: A dual GIP and GLP-1 receptor agonist that produced greater weight loss than semaglutide in head-to-head trial data.

Which has stronger evidence, Semaglutide or Tirzepatide?

They sit at the same evidence level: regulator approved. Semaglutide has about 90 human studies and Tirzepatide about 60.

Are Semaglutide and Tirzepatide 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). Tirzepatide: Type 2 diabetes mellitus (Mounjaro); Chronic weight management (Zepbound); Moderate to severe obstructive sleep apnoea in adults with obesity.

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 156588324) ↗ · structure, identifiers, synonyms
  6. DailyMed: FDA-approved labeling for Tirzepatide ↗ · indications, dosing, warnings as approved
  7. FDA Drugs@FDA database ↗ · approval history
  8. CAS Registry Number 2023788-19-2 ↗ · 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. Jastreboff AM, le Roux CW, Stefanski A, et al.. Tirzepatide for Obesity Treatment and Diabetes Prevention.N Engl J Med 2025.PubMed 39536238 · doi:10.1056/NEJMoa2410819
  10. Jastreboff AM, Aronne LJ, Ahmad NN, et al.. Tirzepatide Once Weekly for the Treatment of Obesity.N Engl J Med 2022.PubMed 35658024 · doi:10.1056/NEJMoa2206038
  11. Aronne LJ, Sattar N, Horn DB, et al.. Continued Treatment With Tirzepatide for Maintenance of Weight Reduction in Adults With Obesity: The SURMOUNT-4 Randomized Clinical Trial.JAMA 2024.PubMed 38078870 · doi:10.1001/jama.2023.24945
  12. Malhotra A, Grunstein RR, Fietze I, et al.. Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity.N Engl J Med 2024.PubMed 38912654 · doi:10.1056/NEJMoa2404881
  13. Packer M, Zile MR, Kramer CM, et al.. Tirzepatide for Heart Failure with Preserved Ejection Fraction and Obesity.N Engl J Med 2025.PubMed 39555826 · doi:10.1056/NEJMoa2410027
  14. Look M, Dunn JP, Kushner RF, et al.. Body composition changes during weight reduction with tirzepatide in the SURMOUNT-1 study of adults with obesity or overweight.Diabetes Obes Metab 2025.PubMed 39996356 · doi:10.1111/dom.16275

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.