Tirzepatide works on two gut hormone signals, GLP-1 and GIP. This is why it is called a dual agonist. It lowers appetite, helps you feel full sooner and improves how your body handles sugar.
Zepbound vs Mounjaro
Both contain tirzepatide. Zepbound is approved for chronic weight management and for moderate to severe obstructive sleep apnea in adults with obesity. Mounjaro is approved for type 2 diabetes. For weight loss, Zepbound is the approved choice.
Tirzepatide results
In the SURMOUNT-1 trial, adults taking the highest dose of tirzepatide lost about 21 percent of their body weight on average over 72 weeks. In a head-to-head study, tirzepatide led to more weight loss than semaglutide. See our full semaglutide vs tirzepatide comparison.
How tirzepatide is dosed
Tirzepatide is a once-weekly injection. It starts at 2.5 mg and usually goes up by 2.5 mg every four weeks as needed, up to 15 mg. Many people do well on a middle dose. Dr. Siddiqui raises the dose slowly to limit side effects.
Side effects and safety
- Common: nausea, diarrhea, constipation, vomiting, indigestion and belly pain.
- Less common but serious: pancreatitis, gallbladder disease, kidney problems from dehydration and low blood sugar when used with insulin or sulfonylureas.
- Boxed warning: thyroid C-cell tumors in animal studies. Not for people with a history of medullary thyroid cancer or MEN 2.
- Birth control pills may work less well for a short time after starting or raising the dose. Ask about a backup method.
Eating smaller meals, stopping when full, avoiding greasy food and drinking enough water helps most people feel better on tirzepatide.
Fast weight loss can include some muscle loss. We encourage protein at each meal and regular strength training so more of the weight you lose is fat.