What is the Tirzepatide Starting Dose for Weight Loss?

Medical Disclaimer: This article provides educational information only and does not offer medical advice. Compounding pharmacies do not receive FDA approval for their medications and may introduce different risks compared to FDA-approved drugs. Speak with a qualified healthcare provider before choosing any medication.

Important Current Status Update: On March 19, 2025, the FDA ended enforcement discretion for compounded tirzepatide. Pharmacies may no longer legally compound tirzepatide in most cases, since the FDA confirmed that no drug shortage exists. Patients should use FDA-approved medications like Mounjaro® and Zepbound® unless a provider confirms a medical necessity.

Tirzepatide is a dual GIP/GLP‑1 receptor agonist gaining attention for its potential in weight management. If you’re looking to get started, it’s important to understand the tirzepatide starting dose and the dosing schedule. 

Patients often begin with 2.5 mg once weekly, which serves as an introductory dose to help the body adapt and may reduce early side effects like mild gastrointestinal discomfort.

A healthcare provider typically evaluates response—such as tolerability, side effects, appetite, and weight changes—before recommending a gradual dosing adjustment.

In the U.S., Tirzepatide is available as:

• Mounjaro – FDA‑approved since May 2022 for type 2 diabetes management.

• Zepbound – FDA‑approved since November 2023 for chronic weight management in adults with obesity or overweight and a weight‑related condition.

Typical Dose Adjustment Schedule

Below is a tirzepatide dose chart to help you understand the schedule outlined by Eli Lilly, the manufacturer of both Mounjaro and Zepbound. Tirzepatide doses are frequently evaluated every 4 weeks to monitor for side effects and efficacy.

Clinical Trial Evidence

SURMOUNT‑1 (Phase 3)

• Non-diabetic adults with obesity received tirzepatide (5, 10, or 15 mg weekly) + lifestyle measures vs. placebo for 72 weeks.

• Average weight reductions were ~15%, ~19.5%, and ~20.9% respectively vs. ~3.1% in placebo.

• DXA scans showed ~21.3% total weight loss, with ~34% from fat mass, and ~11% from lean mass.

SURMOUNT‑1 Follow‑up (3‑year study)

• At 176 weeks, participants on tirzepatide maintained significant weight loss: ~12.3% (5 mg), ~18.7% (10 mg), ~19.7% (15 mg) vs. 1.3% gain on placebo.

• Most regained less than 5% after stopping therapy.

Diabetes‑Risk Reduction Trial (3 years)

• In overweight/pre-diabetic adults, tirzepatide reduced progression to type 2 diabetes by 94%, with ~22.9% average weight loss at highest dose.

SURMOUNT‑3 & SURMOUNT‑4

• Participants who lost weight via lifestyle program, then added tirzepatide (10 or 15 mg) saw further ~18.4% loss over 72 weeks compared to weight gain in placebo.

• In withdrawal studies, continued use maintained ~25.3% weight loss vs. ~9.9% regain in placebo groups.

Comparative Trials

• Head-to-head data suggest tirzepatide (Zepbound) achieved ~20.2% mean weight loss at 72 weeks versus ~13.7% with semaglutide (Wegovy).

Summary of FDA‑Approved Products

• Mounjaro: Approved for type 2 diabetes (May 2022); often prescribed off‑label for weight loss.

• Zepbound: Approved specifically for chronic weight management (Nov 2023); trials show ~18–21% mean weight loss at 72 weeks.

Exploring Tirzepatide with Heally

Heally provides telehealth access to licensed healthcare providers who can determine if tirzepatide is appropriate based on your health profile, treatment goals, and medical history. Dosage decisions and adjustments are individualized and guided by clinical evidence. Register today!

Sources

1. Eli Lilly: Your weekly Zepbound routine
2. FDA access data: Zepbound® (tirzepatide) Prescribing Information – starting dose 2.5 mg once weekly (accessdata.fda.gov)
3. FDA access data: Updated Zepbound label confirming dose escalation schedule (accessdata.fda.gov)
4. FDA access data: Highlights of prescribing info reaffirm starting and maintenance doses (accessdata.fda.gov)
5. Journal (NEJM): SURMOUNT‑1 trial showing substantial sustained weight loss at 5, 10, and 15 mg doses (PubMed/NEJM)
6. Journal (PubMed): Substudy of SURMOUNT‑1 with DXA body composition data (~21.3% loss) (PubMed)
7. Journal (PubMed): 3-year SURMOUNT‑1 follow-up in obese and pre-diabetic participants – durable weight loss & diabetes prevention (PubMed)
8. FDA access data: Mounjaro® Prescribing Information – starting dose 2.5 mg once weekly for diabetes (accessdata.fda.gov)
9. Journal (NEJM): Head‑to‑head trial vs semaglutide showing superior reductions in weight & waist at week 72 (NEJM DOI)
10. Journal (AppliedClinicalTrials): SURMOUNT‑5 Phase IIIb head‑to‑head trial data confirming greater weight loss over 72 weeks (AppliedClinicalTrials)
11. Reuters: Report on diabetes risk reduction trial—94% reduction in progression, ~22.9% weight loss (Reuters)
12. Time: FDA Approval of Zepbound for Weight Loss (Time)
13. American College of Cardiology: Tirzepatide Once Weekly for the Treatment of Obesity – SURMOUNT-1 (acc.org)
14. The Guardian: People using drug Mounjaro sustain weight loss over three years, trial finds (The Guardian)
15. Clinical Trails: A Study of Tirzepatide in Participants With Obesity or Overweight (SURMOUNT-1) (NIH Clinal Trials)
16. Journal (PubMed): Tirzepatide Once Weekly for the Treatment of Obesity (PubMed)

Important Medical Information and Disclaimers

MEDICAL DISCLAIMER: This information is for educational purposes only and is not intended as medical advice. Tirzepatide is available as FDA‑approved prescription medications—Mounjaro® (for type 2 diabetes) and Zepbound® (for chronic weight management and obstructive sleep apnea in adults with obesity). Always consult a qualified healthcare provider before starting any treatment.

INDIVIDUAL RESULTS VARY: Outcomes with tirzepatide vary significantly between individuals. Results may be influenced by treatment adherence, lifestyle modifications, individual metabolism, growth and development (in adolescents), underlying health conditions, and emotional wellbeing.

IMPORTANT SAFETY INFORMATION:

• Common side effects: nausea, vomiting, diarrhea, constipation, abdominal discomfort, decreased appetite, and injection-site reactions.

• Serious side effects: have included pancreatitis, gallbladder disease, acute kidney injury, hypoglycemia, and severe allergic or injection-site reactions.

• Thyroid considerations: Animal studies demonstrated thyroid C‑cell tumors; the relevance to humans is unknown. Zepbound/Mounjaro is contraindicated for individuals with a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).

COMPOUNDED VERSIONS WARNING: The FDA has issued alerts regarding compounded tirzepatide, warning that these custom formulations may lack the safety, consistency, and efficacy of FDA-approved medications.

FDA ADVERSE EVENT REPORTING: You are encouraged to report negative side effects of prescription medications. Visit FDA MedWatch at www.fda.gov/medwatch or call 1‑800‑FDA‑1088.