Peptides
Tirzepatide
What is it?
Tirzepatide is a prescription medicine that acts on GIP and GLP-1 receptors. Zepbound is the brand approved for long-term weight reduction in eligible adults and for obstructive sleep apnea in adults with obesity; Mounjaro is a different tirzepatide brand for type 2 diabetes. This page centers weight management. [1]
How does it work?
The two hormone pathways help regulate appetite, food intake, and blood glucose. That can make a sustained calorie reduction easier for some people. It is not a direct muscle-growth treatment, so preserving lean mass still depends on adequate nutrition and resistance training. [1]
What have weight-loss studies found?
In SURMOUNT-1, 2,539 adults with obesity or overweight plus a related condition, without diabetes, were randomized to tirzepatide or placebo for 72 weeks with lifestyle support. Mean weight loss was 15.0%, 19.5%, and 20.9% in the 5, 10, and 15 mg groups, versus 3.1% on placebo. The high-dose result is not a promise for an individual. Digestive side effects were common, especially during dose increases. [2]
What should you know before considering it?
The Zepbound label has a boxed warning about thyroid C-cell tumors in rats; it is contraindicated with personal or family history of medullary thyroid carcinoma or MEN2. Clinicians also consider severe gastrointestinal symptoms, gallbladder disease, pancreatitis concerns, dehydration, and interactions with diabetes medicines. [1]
PRESCRIPTION START
How much?
FORM & SCHEDULE
What it refers to
once weekly for the first 4 weeks
A prescriber guides escalation. The label has a thyroid C-cell tumor warning and important contraindications.
2.5 mg — Zepbound injection once weekly for four weeks is the labeled starting dose. It is increased in 2.5 mg steps after at least four weeks at a dose. The labeled maintenance choices for weight reduction are 5, 10, or 15 mg weekly, chosen for response and tolerability; 15 mg is the maximum. [1]
Read detailed dosing notes
This is the adult prescription schedule for the named product and use, not advice to start or escalate it without a prescriber. [1]