Average Weight Loss in Clinical Trials
Patients on Zepbound (tirzepatide) lost 15-21% of their body weight over 72 weeks in phase 3 trials, depending on dose. At the highest 15 mg dose, average loss was about 21% (48 lbs for a 230 lb person). Lower doses (5 mg) yielded around 15%.[1][2]
Weight Loss by Dose
- 5 mg weekly: ~15% body weight (34 lbs average).
- 10 mg weekly: ~19-20% (44-46 lbs).
- 15 mg weekly: ~21% (48 lbs).
These results came from trials like SURMOUNT-1 (obesity without diabetes) and SURMOUNT-2 (with type 2 diabetes), where participants had BMI ≥30 or ≥27 with comorbidities, followed a reduced-calorie diet, and exercised.[1][3]
Factors Affecting Your Results
Loss varies by starting weight, adherence, diet, exercise, and duration. Heavier patients often lose more pounds but similar percentages. In trials, 85-91% hit ≥5% loss, 57-70% ≥15%, and 34-52% ≥20% at max dose. Diabetes reduces loss by 3-5% vs. non-diabetics.[2][3] Maintenance requires ongoing use; stopping leads to ~14% regain in a year.[4]
Compared to Other Drugs
Zepbound outperforms semaglutide (Wegovy/Ozempic) in head-to-head data: 20.2% vs. 13.7% loss at 72 weeks. Both beat placebo (2-3%).[5]
Timeline of Weight Loss
Rapid early drop (5-10% in 4 months), then plateaus. Max results by 72 weeks; some lose 25%+ long-term.[1]
Side Effects and Safety Notes
Common: nausea, diarrhea, vomiting (20-30%, often mild). Rare: gallbladder issues, pancreatitis. Not for all; consult a doctor. FDA approved for chronic weight management in adults with obesity or overweight plus conditions.[2]
Sources:
[1] NEJM: Tirzepatide Once Weekly for Obesity
[2] FDA Zepbound Label
[3] SURMOUNT Trial Results
[4] JAMA: Weight Regain After GLP-1 Discontinuation
[5] NEJM: Tirzepatide vs. Semaglutide