Tirzepatide (Mounjaro)

Overview

Tirzepatide (Mounjaro, Zepbound) is the first approved dual GIP and GLP-1 receptor agonist, developed for type 2 diabetes and chronic weight management. It mimics two incretin hormones: GLP-1 (which slows gastric emptying, suppresses appetite, and stimulates insulin) and GIP (which improves insulin sensitivity and reduces nausea). The dual mechanism produces greater weight loss than single GLP-1 agonists, with trial results reaching 22.5% body-weight reduction at the maximum dose. Its roughly 5-day half-life enables once-weekly subcutaneous dosing, with steady state reached after about 4 weeks. The standard titration escalates every 4 weeks from 2.5 mg to 15 mg to manage gastrointestinal side effects. Common effects include appetite suppression, delayed gastric emptying, and dose-dependent nausea. The compound is FDA-approved with an extensive clinical evidence base including cardiovascular outcomes trials.

Pharmacokinetic summary

Model tier

Advanced (t½ + Cmax + Tmax + F)

Half-life

5 days

Cmax

5826.67 nmol/L

Tmax

1.5 days

Bioavailability

80%

Typical dose

2.5–15 mg