Tirzepatide dose calculator
Calculate your tirzepatide titration schedule based on the SURMOUNT clinical trial protocol. Escalation every 4 weeks as tolerated.
Tirzepatide is a dual GIP and GLP-1 receptor agonist developed by Eli Lilly and approved by the FDA as Mounjaro (type 2 diabetes) and Zepbound (obesity). It is the first approved dual incretin therapy, targeting two hormone receptors simultaneously to produce greater weight loss than GLP-1 mono-agonists like semaglutide.
This calculator implements the SURMOUNT-1 trial escalation protocol — the clinical methodology used in the pivotal trial that demonstrated a mean 22.5% reduction in body weight at maximum dose. The protocol starts at 2.5mg weekly and escalates every 4 weeks if tolerated, progressing through 5mg, 7.5mg, 10mg, and 12.5mg to a maximum of 15mg weekly.
The escalation schedule is not arbitrary. Each 4-week period is the minimum required to assess tolerability at a given dose before advancement. Rushing escalation increases gastrointestinal side effect burden; the protocol is designed to minimize adverse events while achieving therapeutic weight loss.
This tool is for research purposes only. Enter your current body weight, the week of your protocol, your current dose, and your tolerability status. The calculator determines whether the SURMOUNT protocol recommends escalation, holding at the current dose, or reducing based on tolerability. It also calculates expected weight loss at the SURMOUNT trial average of 22.5% and your personalized target weight.
calc.currentDose
2.5mg
calc.onceWeekly
Recommendation
calc.continueProtocol
Week 1
calc.expectedWeightLoss
22.5 lbs
calc.targetWeight: 77.3 lbs
calc.clinicalRecommendation
Week 1 of 4 at 2.5mg. Continue current dose. Escalation assessment at week 5.
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Frequently asked questions
What is the standard tirzepatide titration schedule from SURMOUNT-1?+
The SURMOUNT-1 protocol starts at 2.5mg weekly for 4 weeks, then escalates to 5mg, 7.5mg, 10mg, 12.5mg, and 15mg — each held for a minimum of 4 weeks before advancing. Total time to maximum dose is approximately 20 weeks if all escalations are tolerated.
What should I do if I have severe nausea on tirzepatide?+
Mild nausea is expected during dose escalation and typically resolves within 1-2 weeks at a new dose level. For moderate nausea affecting daily function, the SURMOUNT protocol recommends holding at the current dose for an additional 4 weeks before attempting escalation. Severe or persistent nausea warrants dose reduction to the previous tolerated dose.
How long does it take to reach the maximum tirzepatide dose of 15mg?+
Following the SURMOUNT protocol with successful escalation at each 4-week mark, it takes approximately 20 weeks (5 months) to reach 15mg from the starting dose of 2.5mg. Many researchers stay at lower doses (5-10mg) if weight loss goals are achieved with good tolerability.
Can tirzepatide cause hypoglycemia without diabetes medications?+
In people without diabetes and not on insulin secretagogues, clinically significant hypoglycemia with tirzepatide is rare. The SURMOUNT trials in non-diabetic participants showed low rates of hypoglycemia. Tirzepatide's glucose-lowering effect is glucose-dependent, meaning the mechanism is blunted at normal glucose levels.
What is the difference between Mounjaro and Zepbound?+
Both contain tirzepatide and are made by Eli Lilly. Mounjaro is FDA-approved for type 2 diabetes management; Zepbound is FDA-approved for chronic weight management in obesity. They are the same molecule at the same doses — the difference is the approved indication.
Research background
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Jastreboff AM, Aronne LJ, Ahmad NN, et al. (2022). Tirzepatide once weekly for the treatment of obesity title: . New England Journal of Medicine. DOI: 10.1056/NEJMoa2206038
Garvey WT, Frias JP, Jastreboff AM, et al. (2023). Tirzepatide once weekly for the treatment of obesity in people with type 2 diabetes title: . The Lancet. DOI: 10.1016/S0140-6736(23)01554-3
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