The Peptide Directory

FDA-approvedDual GIP / GLP-1 receptor agonistWeight lossType 2 diabetesSleep apnea

Tirzepatide

FDA-approved (Mounjaro for type 2 diabetes; Zepbound for weight management and obstructive sleep apnea with obesity).

Last reviewed by The Peptide Directory Editorial Team

What is Tirzepatide?

Tirzepatide is a once-weekly peptide from Eli Lilly that activates both GIP and GLP-1 receptors; it is FDA-approved as Mounjaro for type 2 diabetes and as Zepbound for chronic weight management and for moderate-to-severe obstructive sleep apnea with obesity.

Key takeaways

  1. First approved dual GIP/GLP-1 agonist.
  2. In SURMOUNT-1, mean weight change at 72 weeks was −15.0%, −19.5% and −20.9% on 5, 10 and 15 mg, versus −3.1% on placebo.
  3. Zepbound label: start 2.5 mg weekly, step up by 2.5 mg no sooner than every 4 weeks, maximum 15 mg.
  4. Same boxed thyroid C-cell tumor warning as other GLP-1 class drugs.

What makes Tirzepatide different?

Tirzepatide adds GIP-receptor activity to GLP-1 activity in one molecule. In head-to-head and cross-trial comparisons it has produced larger average weight loss than semaglutide 2.4 mg.

How does Tirzepatide work?

Its GLP-1 activity lowers appetite and glucagon and slows gastric emptying; its GIP activity adds to insulin secretion and may affect fat metabolism and nausea signaling. Net effect: lower calorie intake and better glucose control.

What the clinical evidence actually shows

  • SURMOUNT-1 (NEJM, 2022): 2,539 adults with obesity or overweight without diabetes; 72-week mean weight change −15.0% (5 mg), −19.5% (10 mg), −20.9% (15 mg) vs −3.1% placebo.
  • Zepbound received an additional indication for moderate-to-severe obstructive sleep apnea in adults with obesity; the label lists 10 or 15 mg maintenance for that use.

How much research exists on Tirzepatide?

PubMed indexes 2,637 papers mentioning Tirzepatide in the title or abstract, 2,630 of them from the last five years and 145 tagged as clinical trials (search run October 19, 2026; repeat the search).

Most relevant recent papers

Registered clinical studies

ClinicalTrials.gov lists 303 studies with Tirzepatide as an intervention (see all). Most recent:

Side effects

Most common per the label: nausea, diarrhea, vomiting, constipation, abdominal pain, indigestion, injection-site reactions, fatigue, hair loss and heartburn. Serious warnings mirror the GLP-1 class (thyroid C-cell tumors, pancreatitis, gallbladder problems, kidney injury from dehydration, hypoglycemia with other agents, aspiration risk under anesthesia).

Regulatory & access status

  • Prescription-only, FDA-approved as Mounjaro and Zepbound (2.5 mg to 15 mg strengths).
  • Compounded tirzepatide is not FDA-approved.

Sourcing & safety

Legal access is by prescription of the brand product through a pharmacy, telehealth service or the manufacturer. Online "research" tirzepatide is not for human use.

Doses in labels and trials

Reference only — copied from the FDA label or published research. Not a recommendation.

SourceWhat it says
Zepbound label (weight)Start 2.5 mg once weekly for 4 weeks, then 5 mg; increase in 2.5 mg steps after at least 4 weeks on the current dose. Maintenance 5, 10 or 15 mg; maximum 15 mg weekly.
Zepbound label (OSA)Maintenance 10 mg or 15 mg once weekly.
SURMOUNT-1 trial5, 10 or 15 mg once weekly for 72 weeks.

What the evidence does not show

  • That compounded tirzepatide is equivalent to Zepbound or Mounjaro.
  • That results persist after stopping treatment.
  • Long-term cardiovascular outcome benefit for weight management (separate trials are reporting).

Tirzepatide FAQ

Is tirzepatide FDA-approved?

Yes — as Mounjaro for type 2 diabetes and as Zepbound for chronic weight management and obstructive sleep apnea with obesity.

What is the maximum tirzepatide dose on the label?

The Zepbound label sets a maximum of 15 mg once weekly.

How much weight did people lose on tirzepatide in SURMOUNT-1?

Mean change at 72 weeks was −15.0% on 5 mg, −19.5% on 10 mg and −20.9% on 15 mg, compared with −3.1% on placebo.

How is tirzepatide different from semaglutide?

Tirzepatide activates both GIP and GLP-1 receptors; semaglutide activates GLP-1 receptors only.

Related peptides & comparisons

SemaglutideRetatrutide Semaglutide vs TirzepatideTirzepatide vs Retatrutide Weight Loss

References

  1. Tirzepatide Once Weekly for the Treatment of Obesity, N Engl J Med (2022), PMID 35658024
  2. ZEPBOUND (tirzepatide) prescribing information, FDA (2026)
  3. Tirzepatide — PubChem compound summary (CID 166567236), PubChem

Tirzepatide calculators

Lab arithmetic only: convert a mass to a volume or syringe units at a known concentration with the units converter, or work out a concentration with the reconstitution calculator.

Tirzepatide is a prescription medicine. The legal route is a prescription for the FDA-approved product (Mounjaro, Zepbound), filled by a licensed pharmacy.

Get Tirzepatide via telehealth

Research suppliers that list Tirzepatide

19 vendors in our directory listed a product matching Tirzepatide in their public catalog on October 19, 2026. Listed alphabetically; a listing is not an endorsement. Research use only.

Prices per mg, where we could verify them, are on our price comparison.

Tirzepatide dosing protocol

The FDA-label schedule is reproduced, with sources, on Tirzepatide 15 mg: Zepbound Label Escalation Schedule (2026).

Find clinics offering Tirzepatide

607 verified clinics name Tirzepatide; browse them by state.

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