Tirzepatide
Dual GIP and GLP-1 receptor agonist studied for weight management and glycemic control.
Tirzepatide "Prevents Diabetes." Prevented, Delayed, or Masked?
The prevention result is one of the stronger things in the incretin literature, and the screenshot version of it can't answer any of the three questions that would make it usable.
How it is thought to work
Activates GIP and GLP-1 receptors, reducing appetite, slowing gastric emptying, and improving insulin response.
Tirzepatide is a once-weekly injectable medication that activates two hormone receptors in the body (GIP and GLP-1) to help the pancreas release more insulin when blood sugar is high, lower glucagon, slow digestion, and reduce appetite.
Reported side effects
The most common side effects are nausea, diarrhea, vomiting, and indigestion, which are usually worst when the dose is being increased and tend to improve once the dose stabilizes.
Who should avoid it
People with a personal or family history of medullary thyroid cancer or MEN 2, those who are pregnant, those with prior pancreatitis, severe gut motility disorders, or type 1 diabetes should not use tirzepatide, and those on oral contraceptives need backup birth control when starting or increasing the dose.
What gets monitored
Weight/body-composition trend, glucose/HbA1c, GI tolerance per provider.
What sources report
These are figures published elsewhere, reproduced with their source. Peppersite does not recommend an amount for Tirzepatide or for anything else, and nothing below has been checked against the study it came from.
| Amount | Frequency | Route | Reported by |
|---|---|---|---|
| Standard: 5 mg once weekly · Low: 2.5 mg once weekly · High: 15 mg once weekly | once weeklyCycle length Planning note 4 weeks (Phase 1, 2. | Subcutaneous injection | Peptide Dosing ProtocolsWhat it saysHide(secondary reference; provider confirmation required). Half-life: 5 days. Tirzepatide is administered once weekly, starting at 5 mg. |
| 2.5 mg starting dose, escalating to 5-15 mg maintenance | Once weeklyOngoing (chronic therapy) | subcutaneous or oral | Peptide Protocol WikiWhat it saysHide(secondary reference; provider confirmation required). |
| Standard: 5 mg, 10 mg, or 15 mg once weekly (three approved maintenance doses) · Low: 2.5 mg once weekly · High: 15 mg once weekly | Once weeklyWeeks 1-4 at 2.5 mg, stepping up every 4 weeks; full ladder to 15 mg reached at week 21+ · 4 weeks (Phase 1, 2.5 mg), 8 weeks (through 5 mg), 12 weeks (through 7.5 mg), 16 weeks (through 10 mg), 24 weeks (full ladder to 15 mg) | Subcutaneous injection | Peptide Dosing ProtocolsWhat it saysHide(secondary reference; provider confirmation required). Half-life: 5 days. Tirzepatide is titrated once weekly from 2.5 mg up to a maximum of 15 mg in 2.5 mg increments every 4 weeks via subcutaneous injection. |
| 2.5-15 mg | Once weekly · Any time of dayTitrate over weeks per response/tolerance | subcutaneous | Reference titration range, provider confirm |
- once weeklyCycle length Planning note 4 weeks (Phase 1, 2.
- Subcutaneous injection
- Peptide Dosing Protocols
What it saysHide
(secondary reference; provider confirmation required). Half-life: 5 days. Tirzepatide is administered once weekly, starting at 5 mg.
- Once weeklyOngoing (chronic therapy)
- subcutaneous or oral
- Peptide Protocol Wiki
What it saysHide
(secondary reference; provider confirmation required).
- Once weeklyWeeks 1-4 at 2.5 mg, stepping up every 4 weeks; full ladder to 15 mg reached at week 21+ · 4 weeks (Phase 1, 2.5 mg), 8 weeks (through 5 mg), 12 weeks (through 7.5 mg), 16 weeks (through 10 mg), 24 weeks (full ladder to 15 mg)
- Subcutaneous injection
- Peptide Dosing Protocols
What it saysHide
(secondary reference; provider confirmation required). Half-life: 5 days. Tirzepatide is titrated once weekly from 2.5 mg up to a maximum of 15 mg in 2.5 mg increments every 4 weeks via subcutaneous injection.
- Once weekly · Any time of dayTitrate over weeks per response/tolerance
- subcutaneous
- Reference titration range, provider confirm
- 2.0 mL BAC water for a 40 mg vial
- 40 mg vial + 2.0 mL BAC water = 20 mg/mL; reconstituted solution keeps for ~28 days refrigerated
Common questions
What is the starting dose of tirzepatide?
The starting dose is 2.5 mg once weekly via subcutaneous injection for the first 4 weeks. This is a tolerability dose, not a treatment dose for weight loss or HbA1c. After 4 weeks the dose escalates to 5 mg, the first true maintenance dose. Further escalation occurs in 2.5 mg increments at minimum 4-week intervals up to 15 mg weekly, based on individual tolerance.
What is the highest dose of tirzepatide / Zepbound?
The maximum FDA-approved dose is 15 mg once weekly for both Mounjaro and Zepbound. In SURMOUNT-1 the 15 mg arm averaged −22.5% body weight loss at 72 weeks, only modestly higher than the 10 mg arm at −21.4%. Many users do well at 10 mg without escalating further.
What is tirzepatide's half-life?
Tirzepatide's half-life is approximately 5 days (about 120 hours). With weekly injections, blood levels build up over about 4 weeks before reaching steady state at roughly 1.6× a single dose. That is why each ladder step lasts at least 4 weeks.
How do you convert tirzepatide mg to insulin units?
The cleanest setup is a 40 mg vial with 2.0 mL BAC water, giving 20 mg/mL. At that concentration: 2.5 mg = 12.5 units, 5 mg = 25 units, 7.5 mg = 37.5 units, 10 mg = 50 units, 12.5 mg = 62.5 units, 15 mg = 75 units.
How much weight can you lose on tirzepatide?
In SURMOUNT-1, the 15 mg arm averaged −22.5% body weight loss at 72 weeks, the 10 mg arm −21.4%, and the 5 mg arm −16.0%. In SURMOUNT-5, tirzepatide produced −20.2% weight loss vs −13.7% for semaglutide. These are population averages over 72 weeks, not promises for any individual.
How do you reconstitute tirzepatide?
For a 40 mg lyophilized vial, add 2.0 mL of bacteriostatic water for a 20 mg/mL solution. Inject the water slowly down the inside vial wall, swirl gently (do not shake), and refrigerate at 2–8 °C. Use within 28 days.
Check 40 mg in 2 mL in the calculator →Is tirzepatide FDA-approved?
Yes. Mounjaro was FDA-approved in May 2022 for type 2 diabetes. Zepbound was approved in November 2023 for chronic weight management and in December 2024 for moderate-to-severe obstructive sleep apnea with obesity. Tirzepatide is the first and only FDA-approved dual GIP/GLP-1 receptor agonist.
What is the difference between Mounjaro and Zepbound?
Mounjaro and Zepbound contain the same active drug, tirzepatide, in the same titration ladder. The only differences are the indication on the label and the packaging. Mounjaro is indicated for type 2 diabetes; Zepbound is indicated for chronic weight management and OSA with obesity.
Sources
- 01Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). New England Journal of Medicine (2022)
- 02Aronne LJ, Horn DB, le Roux CW, et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity (SURMOUNT-5). New England Journal of Medicine (2025)
- 03Frias JP, Davies MJ, Rosenstock J, et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2). New England Journal of Medicine (2021)
- 04Rosenstock J, Wysham C, Frias JP, et al. Efficacy and safety of a novel dual GIP and GLP-1 receptor agonist tirzepatide in patients with type 2 diabetes (SURPASS-1). Lancet (2021)
- 05Dahl D, Onishi Y, Norwood P, et al. Effect of Subcutaneous Tirzepatide vs Placebo Added to Titrated Insulin Glargine on Glycemic Control in Patients With Type 2 Diabetes (SURPASS-5). JAMA (2022)
- 06Packer M, Zile MR, Kramer CM, et al. Tirzepatide for Heart Failure with Preserved Ejection Fraction and Obesity (SUMMIT). New England Journal of Medicine (2024)
- 07Malhotra A, Grunstein RR, Fietze I, et al. Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity (SURMOUNT-OSA). New England Journal of Medicine (2024)
- 08U.S. Food and Drug Administration. Mounjaro (tirzepatide) injection — Prescribing Information and Approval History. FDA Drug Approvals (2022)
- 09U.S. Food and Drug Administration. Zepbound (tirzepatide) injection — Prescribing Information and Approval History. FDA Drug Approvals (2023)
- 10Sinha R, Papamargaritis D, Sargeant JA, Davies MJ. Efficacy and Safety of Tirzepatide in Type 2 Diabetes and Obesity Management (meta-analysis of SURPASS). Journal of Obesity & Metabolic Syndrome (2023)
- 11Coskun T, Sloop KW, Loghin C, et al. LY3298176, a novel dual GIP and GLP-1 receptor agonist for the treatment of type 2 diabetes mellitus: From discovery to clinical proof of concept. Molecular Metabolism (2018)
- 12ClinicalTrials.gov. A Study of Tirzepatide (LY3298176) on Cardiovascular Events in Participants With Type 2 Diabetes (SURPASS-CVOT, NCT04255433). ClinicalTrials.gov (2026)
The reference sections above are imported from our compound knowledge base, which classes the evidence for Tirzepatide as human data available. That classification is the knowledge base’s, not ours, our own grade appears only where an audit is linked above. Research use only; nothing here is medical advice or a protocol.
Blend of cagrilintide (amylin analog) and retatrutide (triple GLP-1/GIP/glucagon agonist), studied for weight management.
Blend of cagrilintide (amylin analog) and tirzepatide (GIP/GLP-1 dual agonist), studied for weight management.
Investigational fixed-dose combination of cagrilintide (a long-acting amylin analog) and semaglutide (a GLP-1 receptor agonist), studied once weekly for weight management.
Investigational GLP-1 and glucagon receptor dual agonist studied for weight management and metabolic health.
Investigational triple GLP-1 / GIP / glucagon receptor agonist studied for weight management.
Semaglutide is one of the most widely studied weight-loss and diabetes drugs in the world.