Tirzepatide — dosage, half-life & reference guide

Metabolic & GLP-1 peptide · also known as Mounjaro, Zepbound, LY3298176

The first dual-action GIP/GLP-1 receptor agonist — it activates two gut hormone pathways simultaneously for greater weight loss than GLP-1 alone. Clinical trials showed up to 22.5% body weight loss at the highest dose. FDA-approved for both diabetes (Mounjaro) and obesity (Zepbound), with evidence of preserving more lean mass than single-agonist drugs.

Commonly-researched dose ranges

Tirzepatide is commonly researched at 2.5–15 mg, weekly, by SubQ injection. These are reference ranges from the literature and community use, not a prescription.

Half-life

Estimated half-life: ~5 days. See how it accumulates in the half-life calculator.

Safety & interactions

Across the SURMOUNT program and the FDA Zepbound label, the dominant adverse events are gastrointestinal (nausea, diarrhea, vomiting, constipation), mostly mild-moderate and escalation-related. The label carries a boxed warning for thyroid C-cell tumors based on rodent studies (human relevance undetermined; contraindicated with personal/family history of medullary thyroid carcinoma or MEN 2). Trial-adjudicated acute pancreatitis was ~0.2% (similar to placebo) and gallbladder events ~1.1% vs 0.4% placebo, partly attributable to rapid weight loss. These are trial/label findings to review with your clinician.

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