Tirzepatide Dosing for Weight Loss: A Complete Guide

Tirzepatide, also known by the brand name Mounjaro (and in some regions Zepbound), is a once-weekly injectable medication that has shown promising results in managing obesity and overweight. Originally developed to treat type 2 diabetes, Tirzepatide works by targeting two hormones—GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide)—that help regulate blood sugar, appetite, and satiety.

If you’re considering Tirzepatide for weight loss, understanding the correct dosing schedule is crucial. Below is a detailed breakdown.

Starting Dose and Titration

Tirzepatide dosing is typically gradual to reduce gastrointestinal side effects such as nausea, diarrhea, or vomiting.

• Starting Dose:
  
  2.5 mg injected subcutaneously once weekly for the first 4 weeks.

  This initial dose is not for weight loss effectiveness but to help the body adjust.

• Step-Up Dosing Schedule:
  
  After the first 4 weeks, the dose is gradually increased every 4 weeks:

  • 5 mg once weekly (Weeks 5–8)

  • 7.5 mg once weekly (Weeks 9–12)

  • 10 mg once weekly (Weeks 13–16)

  • 12.5 mg once weekly (Weeks 17–20)

  • 15 mg once weekly (Week 21 onward, if tolerated)

Maintenance Dose

• The maintenance range is usually 5 mg to 15 mg weekly.

• Most patients aiming for weight loss eventually reach 10 mg or 15 mg once weekly, depending on tolerance and results.

• The maximum recommended dose is 15 mg weekly.

Administration Guidelines

• Inject subcutaneously into the abdomen, thigh, or upper arm.

• Rotate injection sites each week.

• Take the injection on the same day each week, at any time of day, with or without meals.

• If you miss a dose, administer it within 4 days (96 hours). If more than 4 days have passed, skip the missed dose and continue as scheduled.

Weight Loss Results

Clinical trials (SURMOUNT series) have shown that:

• At 10 mg and 15 mg doses, patients lost up to 20% of body weight over 72 weeks.

• Lower doses (5–7.5 mg) also produced significant but less dramatic results.