Tirzepatide results: what to expect and when
A weekly GIP/GLP-1 injection with strong diabetes and weight-loss evidence and common stomach side effects.
Also called: Mounjaro, Zepbound, LY3298176, LY-3298176, Tirz.
GLP-1 / GIP / glucagon agonists · Dual GIP and GLP-1 receptor agonist · Evidence: Approved drug.
- Weeks 1-4: Zepbound starts at 2.5 mg weekly; nausea, diarrhea and vomiting are common during dose increases.
- Weeks 5-8: The schedule moves to 5 mg weekly, the lowest weight-management maintenance dose.
- Weeks 9-16, if increasing: Higher-dose paths use 7.5 mg and then 10 mg weekly, with at least four weeks at each dose.
- Week 17 onward, if increasing: The highest-dose path uses 12.5 mg weekly for at least four weeks before 15 mg weekly.
- Week 72: Adults without diabetes in SURMOUNT-1 averaged 15.0-20.9% weight loss across target doses versus 3.1% with placebo.
Zepbound is used weekly for long-term weight management; its main weight-loss trial lasted 72 weeks.
216 date-filtered interventional registry records name tirzepatide; 71 are completed and 46 have posted results. This is a registry inventory, not 216 completed efficacy trials.
Key studies
- First human doses: Early 0.5 mg exposure does not establish long-term wellness microdosing. (source)
- Phase 2: dose finding: Higher doses improved glucose more and caused more stomach upset. (source)
- Phase 2: three starts: Starting dose and step size affect tolerability. (source)
- Early Japanese dosing: A small trial supported weekly dosing in Japanese adults. (source)
- Early Chinese dosing: Slow escalation supported tolerability in a small Chinese study. (source)
- SURPASS-1: Glucose and weight improved without background diabetes drugs. (source)
Related to Tirzepatide
- Semaglutide: A GLP-1 medicine with strong weight, glucose, heart and kidney evidence; dose and formulation matter.
- Retatrutide: An experimental weekly injection with phase 3 weight-loss results.
- Liraglutide: A daily GLP-1 injection approved for weight management and type 2 diabetes.
- Dulaglutide: A weekly GLP-1 medicine approved for type 2 diabetes and lower heart-event risk.
- Exenatide: An older GLP-1 with twice-daily and weekly forms, now widely discontinued.
- Cagrilintide: An unapproved weekly amylin analogue with weight-loss trials and common stomach symptoms.
Sources
- FDA clarifies policies for compounders as national GLP-1 supply begins to stabilize, FDA · 2026
- FDA Proposes to Exclude Semaglutide, Tirzepatide, and Liraglutide on 503B Bulks List, FDA · 2026
- FDA Requests Removal of Suicidal Behavior and Ideation Warning from Glucagon-Like Peptide-1 Receptor Agonist (GLP-1 RA) Medications, FDA · 2026
- FDA’s Concerns with Unapproved GLP-1 Drugs Used for Weight Loss, FDA · FDA · 2026
- The 2026 Monitoring Program, World Anti-Doping Agency · 2026
- Therapeutic Goods (Poisons Standard—October 2026) Instrument 2026, Australian Government · Australian Government · 2026
- Nutritional Priorities to Support GLP-1 Therapy for Obesity: A Joint Advisory From the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and the Obesity Society., Mozaffarian D et al. · American journal of lifestyle medicine · 2025
- Update on the glucagon-like peptide-1 receptor agonists (GLP-1 RAs) pharmacy compounding changes, Therapeutic Goods Administration · 2024
- Assessment report: Mounjaro, European Medicines Agency
- DailyMed - MOUNJARO- tirzepatide injection, solution MOUNJARO KWIKPEN- tirzepatide injection, solution, DailyMed
- DailyMed - ZEPBOUND- tirzepatide injection, solution ZEPBOUND KWIKPEN- tirzepatide injection, solution, DailyMed
- GLP-1 medicines for weight loss and diabetes: what you need to know, MHRA · MHRA
- Mounjaro, European Medicines Agency
- MOUNJARO (Eli Lilly Australia Pty Ltd), Therapeutic Goods Administration
- Prescribing, reviewing and stopping tirzepatide, NICE
Sources checked: 2026-10-18.
Information only, not medical advice. Peptifacts does not sell anything and does not link to sellers.