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Tirzepatide

Also known as: Mounjaro, Zepbound, LY3298176
FDA: FDA-approved (Mounjaro for T2D Nov 2022, Zepbound for weight management Nov 2023) WADA: Not prohibited

Tirzepatide is a 39-amino-acid dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist developed by Eli Lilly. It is the first-in-class dual incretin agonist, designed as a synthetic peptide based on the GIP sequence with modifications enabling GLP-1 receptor co-activation. FDA-approved as Mounjaro (type 2 diabetes, 2022) and Zepbound (chronic weight management, 2023), tirzepatide has demonstrated superior weight loss to Semaglutide in head-to-head analyses, with the SURMOUNT trial program showing up to 22.5% body weight reduction. With over 1,870 PubMed publications as of April 2026, it represents the most significant advancement in incretin-based therapy since semaglutide. For educational

This content is for educational and research purposes only. VialBase does not provide medical advice. Consult a healthcare professional before using any peptide.

Molecular weight 4,813.45 Da
Half-life ~5 days 120
CAS number —
Route Subcutaneous
02

Mechanism

Dual GIP/GLP-1 receptor agonist — simultaneously activates glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptors for enhanced metabolic effects

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Dosing

DOSE RANGE 2500–15000 mcg
FREQUENCY 1x weekly
CYCLE LENGTH Ongoing (titrate over 20+ weeks)

Titration: 2.5mg (wk 1-4) → 5mg (wk 5-8) → 7.5mg (wk 9-12) → 10mg (wk 13-16) → 12.5mg (wk 17-20) → 15mg (maintenance). Slower titration than semaglutide.

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Research summary

Study Type Year Key Finding
Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2) Phase 3 RCT (open-label, head-to-head comparison) 2021 Tirzepatide 15mg achieved HbA1c reduction of -2.46% vs -1.86% for semaglutide 1mg
Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1) Phase 3 RCT (double-blind, placebo-controlled) 2022 22.5% mean body weight loss with tirzepatide 15mg at 72 weeks
Tirzepatide Once Weekly for the Treatment of Obesity in People with Type 2 Diabetes (SURMOUNT-2) Phase 3 RCT (double-blind, placebo-controlled) 2023 14.7% mean weight loss with tirzepatide 15mg at 72 weeks in T2D patients
Health-Related Quality of Life and Work-Related Outcomes in People with Obesity Treated with Tirzepatide Cross-sectional real-world study (Adelphi Disease Specific Programme) 2026 Tirzepatide users reported higher SF-36v2 scores than non-medication users
Cost-Effectiveness of Incretin Therapies: A Canadian Lens on Diabetes, Obesity, and Emerging Indications review 2026 GLP-1 receptor agonists and dual agonists (semaglutide, tirzepatide) are now among Canada's costliest outpatient drug classes
GLP-1 Receptor Agonist Use and Wound Outcomes After Free Flap Breast Reconstruction retrospective-cohort 2026 GLP-1 users had significantly lower composite wound complication rates than non-users (9.0% vs 17.1%, p = 0.002) after free flap breast reconstruction
A Study of Tirzepatide in Participants With Obstructive Sleep Apnea and Obesity (SURMOUNT-OSA) — — —
A Study of Tirzepatide in Participants With Heart Failure With Preserved Ejection Fraction and Obesity (SUMMIT) — — —
A Study of Tirzepatide in Participants With Metabolic Dysfunction-Associated Steatotic Liver Disease With Alcohol Component (MetALD) — — —
ALN-2232 Phase 1/2 in Obesity, Alone and Co-Initiated with Tirzepatide — — —
Pharmacogenomics of GLP-1 Receptor Agonists: Precision Medicine in the Age of Ozempic and Mounjaro narrative-review 2026 Inter-individual variability in GLP-1 RA response is large and clinically meaningful — some patients lose >20% body weight while others lose <5%; nausea tolerance varies just as widely
Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1) RCT 2022 Tirzepatide 15mg produced 22.5% mean weight loss at 72 weeks
Tirzepatide for the Treatment of Obesity in People with Type 2 Diabetes (SURMOUNT-2) RCT 2023 Tirzepatide 15mg produced 14.7% weight loss in T2DM patients
Tirzepatide for Weight Management after Withdrawal — the SURMOUNT-4 Randomized Clinical Trial RCT 2024 Continued tirzepatide maintained 25.3% weight loss at 88 weeks
Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2) RCT 2021 All tirzepatide doses superior to semaglutide 1mg for HbA1c reduction
Case Report: Gastric Retention Induced by Tirzepatide in a Patient Undergoing Gastroscopy case-report 2026 42-year-old female on weekly subcutaneous tirzepatide for 1 month developed gastric retention discovered during painless gastroscopy despite a standard 12-hour fast
GIP and GLP-1 as treatment targets in type 2 diabetes and obesity: a dual incretin perspective review 2022 Dual GIP/GLP-1 agonism produces greater weight loss than GLP-1 alone
Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity (SURMOUNT-OSA) RCT 2024 Tirzepatide reduced AHI by ~50-60% in obstructive sleep apnea
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Stacking & interactions

Gut protection and GI side effect mitigation

Lean mass preservation during weight loss

Growth hormone support to counter lean mass loss

Metabolic and mitochondrial support during caloric deficit

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Sourcing

Current prices

Updated today

15mg

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What bloodwork do I need?

Reference ranges are general guidelines. Consult your physician for interpretation.

PRE-CYCLE
  • CMP
  • CBC
  • Lipid Panel
  • Fasting Glucose
  • HbA1c
  • Fasting Insulin
  • Amylase
  • Lipase
  • Thyroid Panel (TSH, Free T3, Free T4)
DURING CYCLE
  • Fasting Glucose
  • HbA1c
  • Lipid Panel
  • Amylase
  • Lipase
POST-CYCLE
  • CMP
  • Lipid Panel
  • Fasting Glucose
  • HbA1c
  • Fasting Insulin
Safety & Regulatory Status
FDA STATUS FDA-approved (Mounjaro for T2D Nov 2022, Zepbound for weight management Nov 2023)
WADA STATUS Not prohibited (as of 2026)

Regulatory status for Tirzepatide may change. Verify current status with your jurisdiction before use. This is not legal or medical advice.

References

  1. Frías JP, Davies MJ, Rosenstock J, et al.. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2). New England Journal of Medicine (2021). PMID: 35143054
  2. Jastreboff AM, Aronne LJ, Ahmad NN, et al.. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). New England Journal of Medicine (2022). PMID: 35658024
  3. Garvey WT, Frias JP, Jastreboff AM, et al.. Tirzepatide Once Weekly for the Treatment of Obesity in People with Type 2 Diabetes (SURMOUNT-2). Lancet (2023). PMID: 37385275
  4. Gibble TH, Leith A, Harrison L, et al.. Health-Related Quality of Life and Work-Related Outcomes in People with Obesity Treated with Tirzepatide. Advances in Therapy (2026). PMID: 41965443
  5. Awadalla L, Iskander S, Chu C et al.. Cost-Effectiveness of Incretin Therapies: A Canadian Lens on Diabetes, Obesity, and Emerging Indications. Canadian Journal of Physiology and Pharmacology (2026). PMID: 42013575
  6. Ha J, Lester E, De May H et al.. GLP-1 Receptor Agonist Use and Wound Outcomes After Free Flap Breast Reconstruction. Journal of Reconstructive Microsurgery (2026). PMID: 42013898
  7. A Study of Tirzepatide in Participants With Obstructive Sleep Apnea and Obesity (SURMOUNT-OSA).
  8. A Study of Tirzepatide in Participants With Heart Failure With Preserved Ejection Fraction and Obesity (SUMMIT).
  9. A Study of Tirzepatide in Participants With Metabolic Dysfunction-Associated Steatotic Liver Disease With Alcohol Component (MetALD).
  10. ALN-2232 Phase 1/2 in Obesity, Alone and Co-Initiated with Tirzepatide.
  11. Kannan S. Pharmacogenomics of GLP-1 Receptor Agonists: Precision Medicine in the Age of Ozempic and Mounjaro. Preprints.org (2026).
  12. Jastreboff, A.M., Aronne, L.J., Ahmad, N.N. et al.. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). New England Journal of Medicine (2022). PMID: 35658024
  13. Garvey, W.T., Frias, J.P., Jastreboff, A.M. et al.. Tirzepatide for the Treatment of Obesity in People with Type 2 Diabetes (SURMOUNT-2). Lancet (2023). PMID: 37385275
  14. Aronne, L.J., Sattar, N., Horn, D.B. et al.. Tirzepatide for Weight Management after Withdrawal — the SURMOUNT-4 Randomized Clinical Trial. JAMA (2024). PMID: 38078870
  15. Frias, J.P., Davies, M.J., Rosenstock, J. et al.. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2). New England Journal of Medicine (2021). PMID: 34170647
  16. Zhao Y. Case Report: Gastric Retention Induced by Tirzepatide in a Patient Undergoing Gastroscopy. Research Square (2026).
  17. Nauck, M.A., D'Alessio, D.A.. GIP and GLP-1 as treatment targets in type 2 diabetes and obesity: a dual incretin perspective. Diabetes Care (2022). PMID: 35202211
  18. Malhotra, A., Grunstein, R.R., Engleman, H.M. et al.. Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity (SURMOUNT-OSA). New England Journal of Medicine (2024). PMID: 38912654