Tirzepatide

Grade A applies only to the FDA-approved brand products (Mounjaro, Zepbound), backed by multiple large phase 3 trials including a cardiovascular outcomes trial; it does not extend to research material.

Strengths: 10, 15, 20, 30, 60, 100, 200 mg
Also known as: Mounjaro (brand), Zepbound (brand), LY3298176, GIP/GLP-1 receptor agonist
Molecule: 39-amino-acid lipidated peptide (dual incretin agonist)
Formula: C225H348N48O68
Mol. weight: 4813.45 g/mol
CAS: 2023788-19-2

Origin

Developed by Eli Lilly on a GIP-like backbone with non-natural Aib residues and a C20 fatty diacid that binds albumin, allowing a roughly 5-day half-life.

How it works

Activates both the GIP and GLP-1 receptors. In studies this raises insulin and lowers glucagon when glucose is high, slows stomach emptying and reduces appetite signaling.

What the research shows

Studied in large phase 3 programs in type 2 diabetes (SURPASS), obesity (SURMOUNT), obstructive sleep apnea, heart failure with preserved ejection fraction (SUMMIT) and cardiovascular outcomes (SURPASS-CVOT). Obesity trials reported average weight reductions of about 20% at the top dose over 72 weeks, and a head-to-head trial reported larger reductions than semaglutide. Open questions include weight maintenance after stopping and the functional effect of lean-mass loss.

Key studies

Jastreboff et al., NEJM 2022 (SURMOUNT-1) 2,539 adults; mean weight change 15.0–20.9% vs 3.1% on placebo over 72 weeks.
Aronne et al., NEJM 2025 (SURMOUNT-5) Head-to-head: 20.2% weight reduction vs 13.7% for semaglutide.
Malhotra et al., NEJM 2024 (SURMOUNT-OSA) Apnea-hypopnea index fell about 20–24 more events per hour than placebo.
Packer et al., NEJM 2024 (SUMMIT) Cardiovascular death or worsening heart failure 9.9% vs 15.3%.

Safety findings

Gastrointestinal effects were most common in trials, especially while doses rose. Brand labels carry a boxed warning for thyroid C-cell tumors seen in rats and warnings for pancreatitis, gallbladder disease and reduced oral-contraceptive effectiveness.

Regulatory status

The molecule is FDA-approved as Mounjaro and Zepbound for specific uses; that approval does not cover research material. FDA declared the shortage resolved in late 2024, ending compounding of copies, and has warned sellers of "research use only" tirzepatide marketed for people. Not prohibited by WADA (monitored).

Catalog notes

Available in 10, 15, 20, 30, 60, 100 and 200 mg. Current-lot certificates cover 10, 20, 30, 60 and 100 mg (99.79–99.85% purity); none is published for 15 or 200 mg. It is one of the catalog's best sellers.

In kits: Metabolix Bundle