Common questions
What is the starting dose of tirzepatide?
The starting dose is 2.5 mg once weekly via subcutaneous injection for the first 4 weeks. This is a tolerability dose, not a treatment dose for weight loss or HbA1c. After 4 weeks the dose escalates to 5 mg, the first true maintenance dose. Further escalation occurs in 2.5 mg increments at minimum 4-week intervals up to 15 mg weekly, based on individual tolerance.
What is the highest dose of tirzepatide / Zepbound?
The maximum FDA-approved dose is 15 mg once weekly for both Mounjaro and Zepbound. In SURMOUNT-1 the 15 mg arm averaged −22.5% body weight loss at 72 weeks, only modestly higher than the 10 mg arm at −21.4%. Many users do well at 10 mg without escalating further.
What is tirzepatide's half-life?
Tirzepatide's half-life is approximately 5 days (about 120 hours). With weekly injections, blood levels build up over about 4 weeks before reaching steady state at roughly 1.6× a single dose. That is why each ladder step lasts at least 4 weeks.
How do you convert tirzepatide mg to insulin units?
The cleanest setup is a 40 mg vial with 2.0 mL BAC water, giving 20 mg/mL. At that concentration: 2.5 mg = 12.5 units, 5 mg = 25 units, 7.5 mg = 37.5 units, 10 mg = 50 units, 12.5 mg = 62.5 units, 15 mg = 75 units.
How much weight can you lose on tirzepatide?
In SURMOUNT-1, the 15 mg arm averaged −22.5% body weight loss at 72 weeks, the 10 mg arm −21.4%, and the 5 mg arm −16.0%. In SURMOUNT-5, tirzepatide produced −20.2% weight loss vs −13.7% for semaglutide. These are population averages over 72 weeks, not promises for any individual.
How do you reconstitute tirzepatide?
For a 40 mg lyophilized vial, add 2.0 mL of bacteriostatic water for a 20 mg/mL solution. Inject the water slowly down the inside vial wall, swirl gently (do not shake), and refrigerate at 2–8 °C. Use within 28 days.
Check 40 mg in 2 mL in the calculator →Is tirzepatide FDA-approved?
Yes. Mounjaro was FDA-approved in May 2022 for type 2 diabetes. Zepbound was approved in November 2023 for chronic weight management and in December 2024 for moderate-to-severe obstructive sleep apnea with obesity. Tirzepatide is the first and only FDA-approved dual GIP/GLP-1 receptor agonist.
What is the difference between Mounjaro and Zepbound?
Mounjaro and Zepbound contain the same active drug, tirzepatide, in the same titration ladder. The only differences are the indication on the label and the packaging. Mounjaro is indicated for type 2 diabetes; Zepbound is indicated for chronic weight management and OSA with obesity.