Starting Dose of Tirzepatide for Weight Loss
The recommended starting dose of tirzepatide for weight loss is 2.5 mg injected subcutaneously once weekly for 4 weeks, followed by an increase to 5 mg once weekly. 1, 2
Dosing Schedule and Titration
Initial phase: 2.5 mg subcutaneously once weekly for 4 weeks 1
- This initial 2.5 mg dose is for treatment initiation only and is not approved as a maintenance dose 1
First maintenance dose: After 4 weeks, increase to 5 mg once weekly 1, 2
Further titration: The dose may be increased in 2.5 mg increments after at least 4 weeks on the current dose, up to a maximum of 15 mg once weekly 1, 2
- Potential maintenance doses: 5 mg, 7.5 mg, 10 mg, 12.5 mg, or 15 mg once weekly
- Maximum dose: 15 mg once weekly
Dose Selection Considerations
- Treatment response: Consider the degree of weight loss achieved at current dose 1
- Tolerability: If patients do not tolerate a maintenance dose, consider a lower maintenance dose 1
- Gastrointestinal side effects: The gradual dose escalation schedule is designed to minimize gastrointestinal adverse reactions 1
Administration Guidelines
- Administer subcutaneously in the abdomen, thigh, or upper arm 1, 2
- Rotate injection sites with each dose 1, 2
- Can be administered at any time of day, with or without meals 1, 2
- Must be used in combination with a reduced-calorie diet and increased physical activity 1, 2
Management of Missed Doses
- If a dose is missed, administer as soon as possible within 4 days (96 hours) after the missed dose 1
- If more than 4 days have passed, skip the missed dose and administer the next dose on the regularly scheduled day 1
- The day of weekly administration can be changed if necessary, as long as the time between two doses is at least 3 days (72 hours) 1
Common Side Effects and Management
- Most common adverse effects are gastrointestinal: nausea (31%), diarrhea (23%), vomiting (12%), and constipation (5%) 2
- Management strategies for gastrointestinal effects include:
- Starting at the low dose and titrating slowly (as per the recommended schedule)
- Reducing meal size
- Avoiding high-fat foods
- Limiting alcohol and carbonated drinks 2
Important Precautions
- Contraindicated in patients with personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2) 1
- Monitor for signs of thyroid tumors (neck mass, dysphagia, dyspnea, persistent hoarseness) 1
- Do not coadminister with other tirzepatide-containing products or GLP-1 receptor agonists 1
The starting dose and titration schedule are critical for minimizing side effects while achieving optimal weight loss outcomes. Clinical trials have shown that tirzepatide produces substantial weight loss (mean reduction of 20.9% from baseline compared to 3.1% with placebo) in adults with obesity when following the recommended dosing protocol 2, 3.