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Tirzepatide

Dual GIP and GLP-1 receptor agonist studied for weight and blood sugar; the active ingredient in Mounjaro and Zepbound.

Molecular formulaC225H348N48O6839 amino acids

What it is

Activates the receptors for the natural hormones GIP and GLP-1. This increases insulin release when blood sugar is high, lowers glucagon, slows stomach emptying and reduces calorie intake, likely through effects on appetite.

Sources [4] [3]

What it is studied for

Researchers study weight, blood sugar, heart and sleep-apnea outcomes. In SURMOUNT-1, 2,539 adults with obesity, or overweight plus a weight-related complication, and without diabetes received tirzepatide or placebo for 72 weeks.

Sources [2] [3] [4]

What the evidence says

Large randomized human trials

SURMOUNT-1 found average weight loss of 15% to 21% with tirzepatide versus 3.1% with placebo; gastrointestinal side effects were most common. These results concern the injected medicine. Labels warn of thyroid C-cell tumors seen in rats; human relevance is unknown. FDA says unapproved versions, including compounded ones, are not reviewed for safety, effectiveness or quality.

Sources [2] [4] [3] [5]

How it was studied

SURMOUNT-1 and the approved medicines use once-weekly injections under the skin. Oral capsules, with or without vitamin B12, were not the form studied.

Sources [2] [3] [4]
Regulatory status

Mounjaro is FDA-approved for type 2 diabetes: with diet and exercise to improve blood sugar from age 10, and to lower major cardiovascular event risk in high-risk adults. Zepbound is approved, with diet and activity, for weight reduction in adults with obesity or overweight plus a weight-related condition, and for moderate to severe sleep apnea in adults with obesity.

Sources [3] [4]

Where to find it

Sold by USA Standard Research, the team behind PeptidesGenie, for research use only. Not for human or veterinary use.

Sources

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Source-checked · 27 Oct 2026