TL;DR
The dual-agonist that knocked semaglutide off its pedestal in a head-to-head.
What is it? A once-weekly GIP/GLP-1 dual agonist from Eli Lilly. Sold as Mounjaro (diabetes) and Zepbound (obesity, sleep apnea with obesity).
What does it do? Activates both incretin receptors at once. Suppresses hunger, slows stomach emptying, and remodels adipose tissue in ways pure GLP-1 drugs can't touch.
Does the evidence hold up? SURMOUNT-1 hit 20.9% body weight loss at 72 weeks. SURPASS-2 beat semaglutide head-to-head on HbA1c and weight. SURMOUNT-OSA cut sleep apnea severity 27-30 events/hour. SUMMIT reduced heart failure events in HFpEF with obesity by 38%.
Who uses it? Endocrinologists, obesity medicine, primary care, and increasingly sleep medicine clinics for the OSA indication.
Bottom line? Best-in-class weight loss. Deepest trial program. The one to beat.
What It Is
Tirzepatide is a first-in-class once-weekly synthetic peptide that activates both the glucose-dependent insulinotropic polypeptide (GIP) receptor and the glucagon-like peptide-1 (GLP-1) receptor. It is a 39-amino-acid linear peptide engineered from the native GIP sequence, with non-proteinogenic aminoisobutyric acid (Aib) residues at positions 2 and 13 to protect against DPP-4 degradation, a C-terminal amide cap, and a C20 fatty diacid moiety covalently attached via a γGlu-2xOEG linker at Lys20. That fatty-acid tail enables reversible albumin binding, which is what drives the drug's ~5-day plasma half-life and supports once-weekly subcutaneous dosing (Coskun et al., Mol Metab 2018; PMID 30473097).
Tirzepatide is marketed as Mounjaro for type 2 diabetes (FDA approved May 13, 2022), as Zepbound for chronic weight management in adults with obesity or overweight with weight-related comorbidities (FDA approved November 8, 2023), and as Zepbound for moderate-to-severe obstructive sleep apnea in adults with obesity (FDA approved December 2024 on the basis of SURMOUNT-OSA). Both brands contain identical active ingredient — only labeling, dose range, and indication differ.
What separates tirzepatide from every selective GLP-1 agonist that preceded it is the GIP component. Native GIP signaling had historically been dismissed as a metabolic dead end — partially because GIP receptors are relatively desensitized in type 2 diabetes and partially because GIP elevation alone does not improve glycemia. The tirzepatide hypothesis was that co-activating both incretin receptors on the same molecule would produce synergistic — not merely additive — effects on insulin secretion, glucagon suppression, energy intake, and adipose tissue biology. Head-to-head data (SURPASS-2) and the obesity program (SURMOUNT-1 through SURMOUNT-4, plus SURMOUNT-OSA) have largely validated that hypothesis — tirzepatide produces the largest weight loss and the largest HbA1c reductions of any injectable incretin to date.
The drug's development trajectory has been unusually rapid: from first-in-human in 2016 to T2D approval in 2022 (6 years), then obesity expansion at 18 months, then OSA expansion at 12 more months. Phase 3 programs in MASH (SYNERGY-NASH), HFpEF + obesity (SUMMIT, positive), and cardiovascular outcomes (SURPASS-CVOT, primary completion expected 2026–27) are all in the pipeline. The cumulative Phase 3 patient exposure dwarfs almost any other peptide compound in recent pharmaceutical history.
Mechanism of Action
Tirzepatide is a balanced dual agonist engineered so that receptor engagement approximates the biology of combined endogenous incretin signaling. Binding affinity at the GIP receptor is roughly equivalent to native GIP; affinity at the GLP-1 receptor is about 5-fold weaker than native GLP-1 — an intentional imbalance that shifts signaling toward sustained, lower-intensity GLP-1R activation with full GIP-R activation. This profile appears to drive both efficacy and tolerability.
- GLP-1 receptor activation (glucose-dependent insulin secretion) — Stimulates pancreatic β-cell insulin release in a glucose-dependent manner, suppresses inappropriate glucagon release from α-cells, slows gastric emptying acutely, and engages central GLP-1R populations (hindbrain, hypothalamus) that reduce energy intake. Because insulinotropic activity is glucose-dependent, intrinsic hypoglycemia risk is low (Coskun et al., 2018).
- GIP receptor activation (adipose biology + glucagon modulation) — Potentiates glucose-dependent insulin secretion, but the more distinctive effects are in adipose tissue and the CNS. GIP-R activation enhances insulin sensitivity in subcutaneous adipose, improves lipid buffering, and — through hypothalamic GIP-R populations — contributes to satiety. Preclinical work suggests GIP co-agonism also mitigates GLP-1-associated nausea via central circuits, which may explain the relatively favorable tolerability profile at high efficacy doses.
- Gastric emptying (transient) — Acute tirzepatide delays gastric emptying to a degree similar to selective long-acting GLP-1 receptor agonists, but tachyphylaxis develops over ~2 weeks of repeated dosing. The early delay contributes to initial satiety and some early-titration GI adverse effects; sustained weight loss depends on central, not gastric, mechanisms.
- Central appetite and reward — fMRI and eating-behavior studies with GLP-1-class agents show decreased food-reward signaling, reduced "food noise," and lower hedonic eating. Tirzepatide mirrors the GLP-1 class plus additional hypothalamic GIP-mediated satiety effects.
- Adipose tissue remodeling — SURPASS-3 MRI substudy and SUMMIT CMR substudy show tirzepatide preferentially reduces visceral and ectopic fat (liver, pancreas, epicardial) beyond what would be expected from weight loss alone. GIP-R activity in subcutaneous adipocytes is the leading mechanistic explanation.
- Hepatic effects (MASH/NAFLD) — In SYNERGY-NASH Phase 2, tirzepatide achieved MASH resolution without fibrosis worsening in 44–62% of participants across doses vs 10% placebo (Loomba et al., NEJM 2024; PMID 38856224). The hepatic benefit is presumably downstream of weight loss, visceral-fat reduction, improved insulin sensitivity, and lipotoxic-substrate clearance.
- Cardio-renal effects — SURPASS-4 post-hoc analysis: slowed eGFR decline and reduced new-onset macroalbuminuria vs insulin glargine (Heerspink et al., Lancet Diabetes Endocrinol 2022; PMID 36152639). SUMMIT: 38% reduction in composite CV death / worsening HF in HFpEF + obesity (Packer et al., NEJM 2025; PMID 39555826).
What the Research Shows
Tirzepatide has the strongest human-efficacy evidence base of any compound on this site. The SURPASS (T2D), SURMOUNT (obesity), SURMOUNT-OSA (sleep apnea), SYNERGY-NASH (MASH), and SUMMIT (HFpEF + obesity) programs together enrolled tens of thousands of patients across global Phase 2 and Phase 3 trials.
- SURPASS-1 (Rosenstock 2021; PMID 34186022) — Drug-naïve T2D, 40 weeks. HbA1c reductions 1.87–2.07% across 5/10/15 mg vs –0.04% placebo; 88% of 15 mg patients reached HbA1c <7%; weight loss 7.0–9.5 kg.
- SURPASS-2 (Frías 2021; PMID 34170647) — Head-to-head vs semaglutide 1 mg on background metformin, 40 weeks. Tirzepatide 5/10/15 mg: HbA1c –2.01/–2.24/–2.30% vs –1.86% semaglutide; weight loss 7.6/9.3/11.2 kg vs 5.7 kg. Superiority on both endpoints at all doses.
- SURPASS-3, -4, -5 — vs insulin degludec (PMID 34370970), vs insulin glargine in high CV-risk T2D (PMID 34672967), added to glargine (PMID 35133415). Tirzepatide outperformed basal insulins on HbA1c and weight with favorable hypoglycemia profile.
- SURMOUNT-1 (Jastreboff 2022; PMID 35658024) — 72 weeks, 2,539 adults with obesity without diabetes. Mean weight loss: –15.0% (5 mg), –19.5% (10 mg), –20.9% (15 mg) vs –3.1% placebo. 57% of 15 mg participants lost ≥20%; 36% lost ≥25%.
- SURMOUNT-2 (Garvey 2023; PMID 37385275) — 72 weeks, obesity + T2D. Weight loss 13.4% (10 mg) / 15.7% (15 mg) vs 3.3% placebo.
- SURMOUNT-4 withdrawal (Aronne 2024; PMID 38078870) — 36-week lead-in then randomization to continue or placebo. Continued arm lost additional 5.5%; placebo regained 14%. Confirms maintenance therapy paradigm.
- SURMOUNT-1 3-yr prediabetes (Jastreboff 2025; PMID 39536238) — Sustained weight loss over 3 years; ~93% reduction in progression to T2D vs placebo.
- SURMOUNT-OSA (Malhotra 2024; PMID 38912654) — 52 weeks in moderate-to-severe OSA + obesity. AHI reduction 27.4–30.4 events/hr; basis for FDA OSA indication December 2024.
- SYNERGY-NASH (Loomba 2024; PMID 38856224) — 52-week Phase 2 in biopsy-confirmed MASH with F2/F3 fibrosis. MASH resolution without fibrosis worsening 44/56/62% (5/10/15 mg) vs 10% placebo.
- SUMMIT (Packer 2025; PMID 39555826) — 731 patients with obesity-related HFpEF. Primary composite (CV death or worsening HF event) reduced ~38% over median 104-week follow-up. KCCQ-CSS improved substantially; 6-MWD improved ~18 m vs placebo. CMR substudy showed reductions in LV mass and paracardiac adipose (Kramer et al., 2025).
Context — What This Evidence Does and Does Not Show
Tirzepatide has strong, replicated Phase 3 efficacy evidence across glycemic, weight, OSA, liver, and HFpEF endpoints. What is still missing: a completed dedicated MACE cardiovascular outcomes trial (SURPASS-CVOT vs dulaglutide is ongoing, primary completion expected late 2026), long-term (>5 year) durability and adverse event data, MASH Phase 3 histologic outcomes, and a large body of real-world safety data for the rapidly expanding obesity population. Many of the most concerning signals (pancreatitis, biliary disease, gastroparesis, muscle/bone loss during rapid weight loss, mood changes) are class- or rate-of-weight-loss-related, not uniquely tirzepatide, but they apply here too.
Human Data
Tirzepatide's human dataset is among the largest in modern peptide pharmaceutical development:
- SURPASS program (T2D) — SURPASS-1 through SURPASS-5 + SURPASS J-mono + SURPASS J-combo. N > 6,000. NCT03954834, NCT03987919, NCT03882970, NCT03730662, NCT04039503.
- SURMOUNT program (obesity) — SURMOUNT-1 through SURMOUNT-5. N > 5,000. NCT04184622, NCT04657003, NCT04657016, NCT04660643, NCT05536804.
- SURMOUNT-OSA — NCT05412004. Two master-protocol arms (with/without baseline CPAP); pooled analyses supported OSA label expansion.
- SYNERGY-NASH — NCT04166773. Phase 2 histologic endpoint; Phase 3 program in development.
- SUMMIT — NCT04847557. HFpEF + obesity. Positive for clinical and imaging endpoints.
- SURPASS-CVOT — NCT04255433. Dedicated CV outcomes trial vs dulaglutide in T2D with established CVD; primary completion late 2026.
- Pharmacokinetics — Half-life ~5 days; steady-state at 4 weeks; exposure ~2× higher in obesity doses. Dose adjustment not required for renal or hepatic impairment (Urva et al., 2021, 2022; Schneck & Urva, 2024).
Dosing from the Literature
Tirzepatide is an FDA-approved drug; the following reflects labeled prescribing in the United States. This does not substitute for a prescribing clinician's instructions.
| Indication | Starting Dose | Dose Escalation | Maximum Dose |
|---|
| Type 2 diabetes (Mounjaro) | 2.5 mg SC once weekly × 4 weeks | Increase by 2.5 mg every 4 weeks as tolerated | 15 mg SC once weekly |
| Obesity / overweight (Zepbound) | 2.5 mg SC once weekly × 4 weeks | Increase by 2.5 mg every 4 weeks as tolerated | 15 mg SC once weekly |
| OSA with obesity (Zepbound) | 2.5 mg SC once weekly × 4 weeks | Increase by 2.5 mg every 4 weeks as tolerated | 10 or 15 mg SC once weekly |
| Maintenance doses | 5 mg, 10 mg, or 15 mg once weekly. Maintenance individualized to weight goal, tolerability, and comorbidity response. |
| Missed dose | If <4 days late, take as soon as possible. If >4 days late, skip and resume normal schedule. Do not double-dose. |
Dosing Disclaimer
Tirzepatide is a prescription medication. Optimal dosing is individualized by a licensed prescriber based on indication, comorbidities, renal/hepatic function, concomitant medications, and tolerability. Escalating faster than the 4-week interval increases GI adverse events substantially. This profile is educational and does not replace the prescribing label or your clinician.
Reconstitution & Storage
Branded tirzepatide (Mounjaro / Zepbound) is supplied as a pre-filled, ready-to-inject single-dose pen or single-dose vial — no reconstitution required. Compounded tirzepatide (lyophilized powder requiring BAC-water reconstitution) exists in narrower form; the legal landscape has shifted since FDA resolved the tirzepatide shortage in late 2024.
| Product | Presentation | Concentration | Dose per unit | Storage |
|---|
| Mounjaro / Zepbound pen | 0.5 mL single-dose auto-injector | 2.5, 5, 7.5, 10, 12.5, or 15 mg / 0.5 mL | One pen = one weekly dose | Refrigerate 36–46°F (2–8°C). May be stored at room temp up to 86°F for 21 days. |
| Zepbound single-dose vial | 0.5 mL glass vial | Matched per-strength to pen | Drawn into separate syringe | Same as pen. |
| Compounded 10 mg vial (lyophilized) | Powder — requires reconstitution | Typical: 10 mg in 1 mL BAC water = 10 mg/mL | 2.5 mg = 25 units (0.25 mL); 5 mg = 50 units | Refrigerate after reconstitution; 28–42 days depending on compounder. |
| Compounded 15 mg vial (lyophilized) | Powder — requires reconstitution | Typical: 15 mg in 1.5 mL BAC water = 10 mg/mL | Same as above | Refrigerate after reconstitution. |
- Injection site rotation — Abdomen (avoiding 2 inches around navel), thigh, or upper arm (caregiver-administered). Rotate weekly to minimize lipohypertrophy and site reactions.
- Warming — Allowing the pen to reach room temperature for 15–30 minutes before injection typically reduces discomfort.
- Inspection — Clear and colorless. Discard if cloudy, discolored, or particulate.
- Needle — Branded pens contain a pre-attached hidden needle. For vial use, 29–31G ½-inch insulin syringes are standard.
→ Use the Kalios Dosing Calculator for exact syringe units on compounded vials
Side Effects & Risks
Important
This is a medication. Side effects are real. Below is what the trial data shows — worth discussing with your doctor before starting or switching.
Tirzepatide's safety profile is broadly consistent with the GLP-1 receptor agonist class, with a handful of boxed and class-specific concerns.
- Gastrointestinal (most common) — Nausea (up to ~33% at high doses), diarrhea (~19%), constipation (~12%), vomiting (~10%), dyspepsia, abdominal pain. Most GI events are mild-to-moderate, occur during dose escalation, and resolve with continued dosing or slower titration.
- Boxed warning — thyroid C-cell tumors — In rats, tirzepatide causes dose- and duration-dependent thyroid C-cell tumors at clinically relevant exposures. Human relevance unknown. Contraindicated in personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).
- Pancreatitis — Acute pancreatitis reported in GLP-1 class trials including tirzepatide. Discontinue if suspected; do not restart if confirmed. Caution in prior pancreatitis history.
- Gallbladder disease — Cholelithiasis and cholecystitis elevated on rapid weight loss; partly class effect, partly weight-loss-related.
- Gastroparesis / delayed gastric emptying — Symptomatic gastroparesis reported. Pre-operative considerations (aspiration risk during anesthesia) have led professional societies to recommend temporarily holding GLP-1-class agents before elective procedures.
- Hypoglycemia — Low with monotherapy due to glucose-dependent insulinotropic activity. Increased when combined with insulin or sulfonylureas; those agents typically require dose reduction on initiation.
- Acute kidney injury — Volume depletion from severe vomiting/diarrhea can precipitate AKI, especially in elderly or those on diuretics/ACEi/ARBs. Hydrate aggressively during GI upset.
- Injection-site reactions — Mild erythema, pruritus, or bruising. Typically self-limited.
- Suicidal ideation / mood — Post-marketing reports raised concern. Large registry analyses do not show clear excess signal vs matched controls, but mood monitoring is reasonable.
- Lean mass loss — Rapid weight loss from any cause produces fat-mass and lean-mass loss. Resistance training and protein (≥1.6 g/kg/day) during active weight loss are the best-validated countermeasures.
- Pregnancy + oral contraceptives — Reduces oral contraceptive efficacy via delayed gastric emptying; switch to non-oral or add barrier for 4 weeks after initiation and each dose increase. Not recommended in pregnancy/breastfeeding; discontinue ≥2 months before planned conception.
- Diabetic retinopathy — Rapid glycemic improvement can transiently worsen retinopathy; baseline eye exam and monitoring recommended.
Bloodwork & Monitoring
Monitoring overlaps with standard metabolic / weight-management labs. Typical cadence: baseline, 3 months, then every 6 months depending on indication.
- HbA1c + fasting glucose — For diabetes, expect ~2% HbA1c reduction by 3–6 months. For non-diabetic weight management, still useful for tracking metabolic response.
- Comprehensive metabolic panel — Liver enzymes, renal function (eGFR, creatinine), electrolytes. Recheck during GI adverse events to catch AKI early.
- Lipid panel — Triglycerides and non-HDL-C typically improve; LDL-C modest change; HDL-C relatively stable.
- Lipase / amylase (selective) — Not routinely required; reasonable if abdominal pain develops.
- Vitamin D, B12, iron studies — Reduced food volume can cause micronutrient dips. Baseline and annual.
- DEXA body composition — Useful during active weight-loss phase to quantify lean-mass preservation.
- Blood pressure + heart rate — SBP typically decreases 5–10 mmHg; HR may increase modestly (class effect).
- Thyroid exam (selective) — Not routine screening, but unexplained neck mass, dysphagia, or persistent hoarseness warrants evaluation.
Commonly Stacked With
Adjunct for gut-protection during high-nausea, low-food-volume early titration. Oral BPC-157 is stable in gastric juice and reported anecdotally to reduce GI discomfort. No controlled evidence. Use under clinician guidance.
Common pairing during active tirzepatide weight loss to preserve lean mass via GH pulsatility. Rationale: rapid weight loss produces fat + lean-mass loss; GH secretagogues may bias toward greater fat oxidation. No head-to-head tirzepatide trials; mechanistically coherent.
FDA-approved specifically for visceral adipose tissue reduction in HIV-lipodystrophy. Used off-label alongside tirzepatide in patients with disproportionate visceral adiposity or MASH. Overlapping visceral-fat effects; no combination data.
Next-generation triple GIP/GLP-1/glucagon agonist. Not a concurrent stack — these are alternatives. Patients switching from tirzepatide to retatrutide (via trials) typically do so for greater weight-loss ceiling. Do not co-administer.
Not a stack — direct competitors. Never used simultaneously. Patients transition between them based on insurance, access, or tolerability. SURPASS-2 and SURMOUNT-5 show tirzepatide superior efficacy at matched or higher doses.
→ Check compound compatibility in the Stack Builder
Regulatory Status
Current Status — April 2026
Tirzepatide is an FDA-approved prescription medication available in the United States as Mounjaro (approved May 13, 2022) for adults with type 2 diabetes mellitus and as Zepbound (approved November 8, 2023) for chronic weight management in adults with obesity (BMI ≥30) or overweight (BMI ≥27) with at least one weight-related comorbidity. In December 2024, Zepbound received an additional indication for moderate-to-severe obstructive sleep apnea in adults with obesity, based on the SURMOUNT-OSA trial.
The FDA resolved the tirzepatide shortage in late 2024. Under sections 503A/503B of the FD&C Act, compounding of drugs on the FDA shortage list is permitted; once resolved, compounding of "essentially a copy" of an approved drug is restricted to documented clinical need. Compounded tirzepatide availability is therefore significantly narrower than during the 2022–2024 shortage window. Legal compounded supply now typically requires patient-specific clinical justification (e.g., documented allergy to an inactive ingredient, or a clinically required dose not commercially available).
Tirzepatide is not on the WADA Prohibited List. The FDA boxed warning for thyroid C-cell tumors applies to both brands. Ongoing major trials: SURPASS-CVOT (cardiovascular outcomes), SYNERGY-NASH Phase 3 (MASH histology), and SURMOUNT-MMO (morbidity/mortality in obesity).
Cost & Access
Brand pricing (FDA-approved Eli Lilly products): Mounjaro and Zepbound are priced at standard branded-drug tier for the diabetes / obesity pharmaceutical category in the United States. Eli Lilly's LillyDirect single-dose vial program offers Zepbound at reduced cash-pay tier for lower doses; manufacturer savings programs substantially reduce out-of-pocket cost for qualifying insured patients. Insurance coverage varies widely — most commercial plans and Medicare Part D cover Mounjaro for documented type 2 diabetes; Zepbound coverage for obesity and OSA remains variable across payers and is evolving rapidly.
503B / 503A compounded pricing: Compounded tirzepatide was widely available during the FDA-declared tirzepatide shortage of 2022–2024 at substantially lower price points than branded product. With the shortage resolved in October 2024 and Eli Lilly's active litigation against compounding pharmacies, 503A / 503B compounded availability has narrowed substantially. Some clinics continue to dispense via 503A pharmacies for clinician-documented patient-specific medical necessity, though this pathway has tightened under FDA enforcement.
Tirzepatide is not on the Category 2 bulk substance list addressed by HHS Secretary Robert F. Kennedy Jr.'s February 2026 peptide reclassification announcement, which applies specifically to peptide bulk substances historically restricted from compounding. Tirzepatide is an FDA-approved branded drug; the regulatory question affecting its compounded supply is the FDA shortage list and active manufacturer litigation, not the Category 2 framework.
Estimated pricing as of April 2026. Actual costs vary by provider, location, and prescription status. Kalios does not sell compounds.
Related Compounds
People researching tirzepatide often also look at these:
SURMOUNT-5 head-to-head (NEJM 2025) — weight loss, CV outcomes, side effects, cost, and when to choose which.
Fixed-dose combination of cagrilintide + semaglutide. Amylin + GLP-1 obesity protocol.
Dual GLP-1 / glucagon receptor agonist. Boehringer Ingelheim's competitor to retatrutide.
Dual GLP-1 / glucagon receptor agonist developed by Innovent / Eli Lilly, principally for Asian markets.
Dual GLP-1 / glucagon receptor agonist with emphasis on MASH (liver fat) alongside weight loss.
Key References
- Coskun T, Sloop KW, Loghin C, Alsina-Fernandez J, Urva S, Bokvist KB, et al. LY3298176, a novel dual GIP and GLP-1 receptor agonist for the treatment of type 2 diabetes mellitus: From discovery to clinical proof of concept. Mol Metab. 2018;18:3-14. PMID: 30473097.
- Jastreboff AM, Aronne LJ, Ahmad NN, Wharton S, Connery L, Alves B, et al.; SURMOUNT-1 Investigators. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022;387(3):205-216. PMID: 35658024.
- Jastreboff AM, le Roux CW, Stefanski A, Aronne LJ, Halpern B, Wharton S, et al.; SURMOUNT-1 Investigators. Tirzepatide for Obesity Treatment and Diabetes Prevention. N Engl J Med. 2025;392(10):958-971. PMID: 39536238.
- Frías JP, Davies MJ, Rosenstock J, Pérez Manghi FC, Fernández Landó L, Bergman BK, et al.; SURPASS-2 Investigators. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes. N Engl J Med. 2021;385(6):503-515. PMID: 34170647.
- Rosenstock J, Wysham C, Frías JP, Kaneko S, Lee CJ, Fernández Landó L, et al.; SURPASS-1 Investigators. Efficacy and safety of a novel dual GIP and GLP-1 receptor agonist tirzepatide in patients with type 2 diabetes (SURPASS-1): a double-blind, randomised, phase 3 trial. Lancet. 2021;398(10295):143-155. PMID: 34186022.
- Ludvik B, Giorgino F, Jódar E, Frias JP, Fernández Landó L, Brown K, et al. Once-weekly tirzepatide versus once-daily insulin degludec as add-on to metformin with or without SGLT2 inhibitors in patients with type 2 diabetes (SURPASS-3): a randomised, open-label, parallel-group, phase 3 trial. Lancet. 2021;398(10300):583-598. PMID: 34370970.
- Del Prato S, Kahn SE, Pavo I, Weerakkody GJ, Yang Z, Doupis J, et al.; SURPASS-4 Investigators. Tirzepatide versus insulin glargine in type 2 diabetes and increased cardiovascular risk (SURPASS-4): a randomised, open-label, parallel-group, multicentre, phase 3 trial. Lancet. 2021;398(10313):1811-1824. PMID: 34672967.
- Dahl D, Onishi Y, Norwood P, Huh R, Bray R, Patel H, Rodríguez Á. Effect of Subcutaneous Tirzepatide vs Placebo Added to Titrated Insulin Glargine on Glycemic Control in Patients With Type 2 Diabetes: The SURPASS-5 Randomized Clinical Trial. JAMA. 2022;327(6):534-545. PMID: 35133415.
- Garvey WT, Frias JP, Jastreboff AM, le Roux CW, Sattar N, Aizenberg D, et al.; SURMOUNT-2 Investigators. Tirzepatide once weekly for the treatment of obesity in people with type 2 diabetes (SURMOUNT-2). Lancet. 2023;402(10402):613-626. PMID: 37385275.
- Aronne LJ, Sattar N, Horn DB, Bays HE, Wharton S, Lin WY, et al.; SURMOUNT-4 Investigators. Continued Treatment With Tirzepatide for Maintenance of Weight Reduction in Adults With Obesity: The SURMOUNT-4 Randomized Clinical Trial. JAMA. 2024;331(1):38-48. PMID: 38078870.
- Malhotra A, Grunstein RR, Fietze I, Weaver TE, Redline S, Azarbarzin A, et al.; SURMOUNT-OSA Investigators. Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity. N Engl J Med. 2024;391(13):1193-1205. PMID: 38912654.
- Loomba R, Hartman ML, Lawitz EJ, Vuppalanchi R, Boursier J, Bugianesi E, et al.; SYNERGY-NASH Investigators. Tirzepatide for Metabolic Dysfunction-Associated Steatohepatitis with Liver Fibrosis. N Engl J Med. 2024;391(4):299-310. PMID: 38856224.
- Packer M, Zile MR, Kramer CM, Baum SJ, Hurt K, Litwin SE, et al.; SUMMIT Trial Study Group. Tirzepatide for Heart Failure with Preserved Ejection Fraction and Obesity. N Engl J Med. 2025. PMID: 39555826.
- Heerspink HJL, Sattar N, Pavo I, Haupt A, Duffin KL, Yang Z, et al. Effects of tirzepatide versus insulin glargine on kidney outcomes in type 2 diabetes in the SURPASS-4 trial: post-hoc analysis of an open-label, randomised, phase 3 trial. Lancet Diabetes Endocrinol. 2022;10(11):774-785. PMID: 36152639.
- Schneck K, Urva S. Population pharmacokinetics of the GIP/GLP receptor agonist tirzepatide. CPT Pharmacometrics Syst Pharmacol. 2024;13:494-503. PMID: 38356317.
- Urva S, Quinlan T, Landry J, Ma X, Martin JA, Benson CT. Effects of hepatic impairment on the pharmacokinetics of the dual GIP and GLP-1 receptor agonist tirzepatide. Clin Pharmacokinet. 2022;61(7):1057-1067. PMID: 35507285.
- Urva S, Quinlan T, Landry J, Martin J, Loghin C. Effects of Renal Impairment on the Pharmacokinetics of the Dual GIP and GLP-1 Receptor Agonist Tirzepatide. Clin Pharmacokinet. 2021;60(8):1049-1059. PMID: 33778934.
- U.S. Food and Drug Administration. FDA Approves New Medication for Chronic Weight Management (Zepbound). fda.gov. November 8, 2023.
- Eli Lilly and Company. Mounjaro (tirzepatide) and Zepbound (tirzepatide) Prescribing Information. 2024.
Last updated: April 2026 | Profile authored by Kalios Peptides research team