Tirzepatide

aka LY3298176, Mounjaro, Zepbound

Glp-1 / Gip Dual AgonistWeight LossFat LossObesityDiabetesGlucoseSleep ApneaGlp-1GipMashLiver HealthCardiovascularInsulin

Last reviewed April 27, 2026 by Doserr editorial team · 10 references on this page

Information on this page is sourced from published research and is for educational purposes only. It does not constitute medical advice.

TL;DR

What it is: A synthetic dual GIP and GLP-1 receptor agonist given as a once-weekly subcutaneous injection.
What it's used for: FDA-approved for type 2 diabetes and obesity, produces the largest weight loss of any approved pharmacotherapy, across multiple large RCTs.
Evidence level:strongMultiple large phase 3 RCTs, the strongest evidence base on this site.

Dose at a glance

	Beginner	Common	Higher end
Per dose	2.5 mg SC once weekly	5-10 mg SC once weekly	12.5-15 mg SC once weekly
Daily total	2.5 mg (once-weekly dosing, one injection per week)	5-10 mg (once-weekly dosing, one injection per week)	12.5-15 mg (once-weekly dosing, one injection per week)
Schedule	Once weekly	Once weekly	Once weekly
Cycle length	4 weeks at starting dose, then titrate upward	Indefinite maintenance, most community members find 5-10 mg sufficient	Indefinite maintenance, 15 mg is the FDA-approved maximum

Synthesized from community-reported ranges. Not a recommendation. Route varies by compound — see Common route in What people report below.

Half-life: Approximately 5 days (plasma half-life in humans). Well-characterized in published pharmacokinetic studies. The C20 fatty acid attachment enables albumin binding and extends half-life relative to unmodified GLP-1 peptides, supporting once-weekly SC dosing.
Typical dose range: Doses below are from published research, not recommendations. Phase 3 trials: 5 mg, 10 mg, or 15 mg SC once weekly, initiated at 2.5 mg and escalated by 2.5 mg every 4 weeks. FDA-approved label dose range: 2.5 mg (starting dose) -> 5 mg -> 7.5 mg -> 10 mg -> 12.5 mg -> 15 mg (maximum). Community microdosing during compounding era: sub-2.5 mg weekly, no phase 3 trial data at these doses.
Route: Subcutaneous injection (SC), once weekly. Abdomen, thigh, or upper arm. Branded product: single-dose auto-injector pen (KwikPen). Compounded (historical): insulin syringe via multi-dose vial.
Evidence tier: strong
Multiple human RCTs published with consistent results.

Each topic links to the studies behind it. Click a topic to expand.

Long-term cardiovascular outcomes in non-diabetic obesity populations are not yet established, SURPASS-CVOT used an active comparator (dulaglutide) not placebo, SURMOUNT-MMO has not reported as of April.
Weight regain after discontinuation is substantial and well-documented, SURMOUNT-4 shows 82.5% of participants who stopped tirzepatide regained >= 25% of lost weight within one year (PMID: 38078870, 41284285)
Thyroid C-cell tumor risk in humans is uncharacterized, rodent studies show dose-dependent C-cell tumors, human thyroid has lower GLP-1 receptor density but long-term data are insufficient to rule out risk
Efficacy and safety in non-obese populations are not established, all phase 3 trials required BMI >=.
MASH phase 2 data (SYNERGY-NASH) show histological improvement but phase 3 major adverse liver outcome data are not yet available
Pediatric and pregnancy data are absent, the FDA label states safety and efficacy in children under 18 is not known

Reconstitution math, both directions.

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