COMPOUND

Compounds / GLP-1 agonists

Tirzepatide

Tirzepatide (Mounjaro / Zepbound)

GLP-1 agonists SubQ FDA approved

First-in-class dual GIP / GLP-1 receptor agonist. Produces the largest weight loss seen in head-to-head trials against semaglutide. Mounjaro for T2D; Zepbound for chronic weight management.

At a glance

Half-life
~5 days ~5 days (range 118-132h in population PK). Steady state in 4 weeks of once-weekly dosing. 80% bioavailability SC.
Tmax
~24 h
Routes
SubQ
Evidence base
3 studies 3 human

Mechanism

Agonist at both the glucose-dependent insulinotropic polypeptide (GIP) receptor and the GLP-1 receptor. The dual incretin action amplifies glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and modulates hypothalamic appetite centers. GIP co-agonism is thought to mitigate some of the GLP-1-mediated GI side effect burden while enhancing weight loss efficacy.

Dosing

Any amounts shown here are reported from published studies only. 3 of 3 catalogued studies involved human subjects. COMPOUND does not publish its own dosing guidance.

Where a study reports an amount, it appears in that study's entry below, attributed to the source.

Published evidence

  1. Human RCT 2022

    Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1)

    Jastreboff AM, Aronne LJ, Ahmad NN, et al. N Engl J Med

    20.9% mean weight loss on 15mg vs 3.1% placebo at 72 weeks in non-diabetic obesity (SURMOUNT-1, n=2,539).

    PMID 35658024

  2. Human RCT 2021

    Tirzepatide versus semaglutide once weekly in patients with type 2 diabetes (SURPASS-2)

    Frías JP, Davies MJ, Rosenstock J, et al. N Engl J Med

    Tirzepatide 15mg produced 2.30% HbA1c reduction + 11.2 kg weight loss vs semaglutide 1mg's 1.86% + 5.7 kg at 40 weeks.

    PMID 34170647

  3. Human observational 2024

    Population pharmacokinetic modeling of tirzepatide

    Urva S, Coskun T, Loh MT, et al. Clin Pharmacokinet

    Mean terminal t½ ~5 days; 80% bioavailability SC; 24h Tmax.

    PMID 38356317

Reported side effects

Nausea
Common Mild · Dose-dependent: 13.3% at 5mg, 17.9% at 10mg, 24.1% at 15mg (SURPASS pooled). Peaks at end of each escalation step; diminishes at maintenance.
Diarrhea
Common Mild · Dose-dependent: 13.2% at 5mg, 17.2% at 10mg, 20.8% at 15mg. Occurs throughout treatment, not tightly coupled to escalation.
Vomiting
Common Moderate · Dose-dependent: 5.7% at 5mg (occasional), 8.3% at 10mg, 14.0% at 15mg (common). Concurrent with nausea pattern during escalation.
Constipation
Common Mild · ~10-17% across doses. Responsive to hydration + fiber.
Pancreatitis
Rare Serious · ~0.2-0.3% across SURPASS (SURMOUNT adjudicated: 0.2% vs 0.2% placebo). FDA recommends baseline lipase; recheck if abdominal symptoms develop.
Lean mass loss
Common Moderate · Up to 25-40% of weight lost may be lean mass without resistance training + 1.2-1.6 g/kg/day protein.

Reconstitution and storage

Brand (Mounjaro/Zepbound): pre-filled KwikPens, no reconstitution needed. Compounded: multi-dose vial + syringe.

Unused pens: refrigerate 2-8°C. In-use pen: room temp up to 21 days. Protect from light. Do not freeze.

Open the reconstitution calculator for Tirzepatide