Compound profile

Tirzepatide

GLP-1 / GIP

A dual GLP-1/GIP receptor agonist, FDA-approved under brand names for diabetes and weight management, and widely researched at a range of doses.

Reviewed for accuracy · Last reviewed July 7, 2026
ClassGLP-1 / GIP dual agonist
RouteSubcutaneous injection
Common research range2.5 – 15 mg, weekly
StorageRefrigerated, ~3–4 weeks once mixed

Overview

Tirzepatide acts on both the GLP-1 and GIP receptors, which together slow gastric emptying, reduce appetite, and improve insulin sensitivity. It's given as a once-weekly subcutaneous injection, usually starting low and increasing every four weeks.

Because it's sold as a prefilled pen at fixed doses commercially, people sourcing it independently as a vial often need to work out unit conversions by hand. The chart below is a starting point.

Dosing

The weight-management label starts at 2.5 mg once weekly and increases no sooner than every four weeks to a maximum of 15 mg. Vial users often convert milligrams to insulin-syringe units by hand.

Read the full Tirzepatide dosage guide →

Side effects

Adverse reactions are predominantly gastrointestinal (nausea, diarrhea, vomiting, constipation, abdominal pain), mostly mild to moderate and concentrated during dose escalation. The label carries a boxed warning for thyroid C-cell tumors.

Read the full Tirzepatide side effects guide →

Storage

Keep unmixed vials refrigerated and away from light. Once reconstituted, most research reports store it refrigerated for roughly 3–4 weeks. See the full storage & safety guide for handling and disposal basics.

FAQ

Why does my dose need a stronger mix at higher amounts?A 100-unit insulin syringe only holds 1 mL. Past 5 mg at a 5 mg/mL concentration, the volume no longer fits one syringe, so people often reconstitute with less water at higher doses.
Is compounded tirzepatide the same as the branded pen?The active peptide is the same molecule, but independently compounded or sourced vials carry no guarantee of the purity or accuracy testing that a regulated pharmacy product does.
How long until effects are noticeable?Appetite changes are often reported within the first week or two; weight and metabolic changes typically build over months of consistent dosing.
How many units is 2.5 mg of tirzepatide?At a 5 mg/mL concentration, 2.5 mg is 50 units on a U-100 insulin syringe. The number changes with the mix (2.5 mg is 25 units at 10 mg/mL), so always recalculate from your own vial and water amounts.
How many mg is 20 units of tirzepatide?At 5 mg/mL, 20 units is 1 mg. Divide units by 100 to get mL, then multiply by your concentration in mg/mL.

References

  1. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1)New England Journal of Medicine · 2022 · PMID 35658024 · DOI 10.1056/NEJMoa2206038
  2. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2)New England Journal of Medicine · 2021 · PMID 34170647 · DOI 10.1056/NEJMoa2107519
  3. MOUNJARO (tirzepatide) injection: DailyMed labelDailyMed (U.S. National Library of Medicine) · current · DailyMed setid d2d7da5d-ad07-4228-955f-cf7e355c8cc0
  4. ZEPBOUND (tirzepatide) injection: DailyMed labelDailyMed (U.S. National Library of Medicine) · current · DailyMed setid 487cd7e7-434c-4925-99fa-aa80b1cc776b
Running this protocol? PepHub can log your weekly doses and remind you.Learn more →

This page is an independent educational reference and is not medical advice. Talk to a doctor before starting or adjusting any compound.