Key Takeaways
- Mounjaro indication: FDA-approved May 2022 for glycemic control in adults with type 2 diabetes, as an adjunct to diet and exercise.
- Starting dose: 2.5 mg once weekly for 4 weeks (sub-therapeutic; builds GI tolerance before the first therapeutic dose of 5 mg).
- Titration pace: Increase every 4 weeks based on glycemic response and tolerability: 2.5 → 5 → 7.5 → 10 → 12.5 → 15 mg.
- Maintenance doses: 5 mg, 10 mg, or 15 mg. Your prescriber decides based on HbA1c response and side effects.
- HbA1c reduction: Up to 2.07 percentage points vs placebo at 40 weeks (SURPASS-1, 15 mg).
- Not the same as Zepbound: Same molecule, same doses, but Mounjaro is the T2D brand; Zepbound is the weight management brand.
The starting dose of Mounjaro is 2.5 mg once weekly for 4 weeks. From there, the dose increases by 2.5 mg every 4 weeks, based on your glycemic response and tolerability, until you reach a maintenance dose of 5 mg, 10 mg, or 15 mg. It takes approximately 20 weeks to reach the 15 mg maximum. Most T2D patients achieve strong HbA1c control without needing the highest dose.
This dosage chart covers the Mounjaro T2D indication. For the Zepbound weight management framing, see the tirzepatide dosage chart for Zepbound weight management.
What Is Mounjaro and What Is It Approved For?
Mounjaro is the brand name for tirzepatide, a dual GLP-1 and GIP receptor agonist developed by Eli Lilly. It was FDA-approved in May 2022 as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. You can find more background on the molecule in the complete tirzepatide resource.
Mounjaro works through two receptors. The GLP-1 component stimulates glucose-dependent insulin secretion, suppresses glucagon, and slows gastric emptying. The GIP component adds further insulin sensitization and, at higher doses, contributes to the weight changes seen in T2D patients. The result is a more pronounced HbA1c reduction than GLP-1-only agents at comparable doses.
In SURPASS-1 (Rosenstock et al., Lancet 2021), a phase 3 trial of tirzepatide vs placebo in T2D patients on diet and exercise only, Mounjaro reduced HbA1c by 1.87% to 2.07% vs placebo at 40 weeks. At the 15 mg dose, 52% of participants reached HbA1c below 5.7%, the non-diabetic threshold. These are the primary efficacy endpoints for Mounjaro's T2D indication.
Mounjaro vs Zepbound: Same Doses, Different Indication
Mounjaro and Zepbound contain identical tirzepatide. The same Eli Lilly manufacturing, the same 2.5 mg to 15 mg dose range, the same single-dose KwikPen. The difference is purely the FDA indication and the prescribing context:
- Mounjaro (approved May 2022): Indicated for glycemic control in adults with type 2 diabetes. Primary endpoint: HbA1c reduction. Weight loss is a secondary outcome.
- Zepbound (approved November 2023): Indicated for chronic weight management in adults with BMI ≥ 30, or ≥ 27 with at least one weight-related comorbidity. Primary endpoint: body weight reduction.
For T2D patients, prescribers titrate Mounjaro based on glycemic response. The prescribing information specifies that if additional glycemic control is needed after 4 weeks at a given dose, the dose may be increased. This is the clinical driver, not tolerability alone. See the tirzepatide dosage chart for Zepbound weight management if your prescriber is using the obesity indication.
Mounjaro Dosage Chart: 2.5 mg to 15 mg Titration Schedule
The Mounjaro dosing schedule starts at 2.5 mg once weekly and increases by 2.5 mg every 4 weeks. The dose at week 1 is intentionally sub-therapeutic, designed to build gastrointestinal tolerance. The first therapeutic dose is 5 mg, reached at week 5. If more glycemic control is needed, the prescriber can increase every 4 weeks up to the 15 mg maximum. The full titration to 15 mg takes approximately 20 weeks.
| Phase | Weeks | Dose | Glycemic Purpose |
|---|---|---|---|
| Initiation | 1–4 | 2.5 mg | Sub-therapeutic. Establishes GI tolerance. |
| Escalation 1 | 5–8 | 5 mg | First therapeutic dose. Assess glycemic response. |
| Escalation 2 | 9–12 | 7.5 mg | Intermediate step. Not a maintenance dose. |
| Escalation 3 | 13–16 | 10 mg | Most common T2D maintenance dose. |
| Escalation 4 | 17–20 | 12.5 mg | Intermediate step. Not a maintenance dose. |
| Maximum | 21+ | 15 mg | Highest maintenance dose. Maximum HbA1c reduction. |
Source: Mounjaro (tirzepatide) Prescribing Information, Eli Lilly and Company, 2024.
Important: 2.5 mg, 7.5 mg, and 12.5 mg are stepping-stone doses, not maintenance doses. The true maintenance options are 5 mg, 10 mg, and 15 mg. Your prescriber decides where to keep you based on your HbA1c response and how well you tolerate the medication.
Mounjaro Dosing Outcomes: HbA1c and Blood Sugar Control
Because Mounjaro is a T2D medication, glycemic outcomes are the primary benchmark. The SURPASS clinical trial program provides the most relevant data. SURMOUNT-1 weight loss figures (from an obesity population) are included below as secondary context, but HbA1c reduction is the primary goal of Mounjaro therapy.
HbA1c Reductions from SURPASS-1
SURPASS-1 (Rosenstock et al., Lancet 2021) enrolled T2D patients on diet and exercise alone (no background antidiabetic therapy) and compared tirzepatide to placebo over 40 weeks. At week 40, tirzepatide produced the following HbA1c reductions vs placebo:
| Dose | HbA1c Reduction vs Placebo | % Reaching HbA1c < 5.7% |
|---|---|---|
| 5 mg | -1.87 percentage points | Not primary endpoint at this dose |
| 10 mg | -1.89 percentage points | Not primary endpoint at this dose |
| 15 mg | -2.07 percentage points | 52% reached HbA1c < 5.7% |
Source: SURPASS-1, Rosenstock J et al. Lancet. 2021;398(10295):143-155.
What to Expect at Each Dose (T2D Context)
2.5 mg (Weeks 1–4): GI Tolerance Phase
This dose is deliberately below the therapeutic threshold. No meaningful HbA1c reduction is expected at week 1. Your GI system is adjusting, not responding to the drug yet. You may notice mild appetite suppression, but glycemic changes are minimal.
5 mg (Weeks 5–8): First Therapeutic Dose
Glycemic effects begin here. HbA1c reduction from SURPASS-1: -1.87% vs placebo at 40 weeks. Many T2D patients maintain at 5 mg long-term if glycemic targets are met. In SURMOUNT-1 (obesity population, 72 weeks), the 5 mg dose produced approximately 15% body weight loss as a secondary finding.
10 mg (Weeks 13–16): Most Common T2D Maintenance
The most frequently used maintenance dose in T2D practice. HbA1c reduction from SURPASS-1: -1.89% vs placebo. Weight loss: approximately 19.5% at 72 weeks in SURMOUNT-1 (obesity population). T2D patients generally land somewhat lower on weight loss, but SURMOUNT-2 confirms the effect is still clinically meaningful in people with diabetes.
15 mg (Weeks 21+): Maximum Dose
Highest maintenance dose. SURPASS-1 HbA1c reduction: -2.07% vs placebo; 52% of 15 mg participants reached HbA1c below 5.7%. In SURMOUNT-1, the 15 mg dose produced 20.9% body weight loss at 72 weeks in the obesity population. Not all T2D patients need to reach 15 mg. Prescribers move to this dose only if lower maintenance doses do not achieve glycemic targets.
Note on weight loss figures: The ~15%, ~19.5%, and 20.9% weight loss figures cited above come from SURMOUNT-1, which enrolled adults with obesity or overweight without diabetes. T2D patients in SURMOUNT-2 also achieved significant weight reduction on Mounjaro, though typically somewhat less than in the obesity-primary trials. Weight loss is a secondary outcome of Mounjaro therapy, not its primary indication.
Mounjaro Dosage Forms and the KwikPen
Mounjaro is dispensed as a single-dose KwikPen, a prefilled autoinjector. There are six pen strengths, each color-coded to its dose: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg. Each pen contains one dose only. Patients cannot draw a partial dose from a KwikPen, and pens cannot be reused.
Injection and Storage
- Injection sites: Abdomen, thigh, or upper arm. Rotate sites weekly to avoid lipohypertrophy.
- Inject subcutaneously: Not for intravenous or intramuscular use.
- Day of the week: Mounjaro is taken once weekly, on the same day each week. The day can be changed as long as the gap between doses is at least 3 days (72 hours).
- Refrigerated storage: Store at 2°C to 8°C (36°F to 46°F) until the expiration date.
- Room temperature: A single pen may be kept at room temperature up to 30°C (86°F) for up to 21 days once removed from the refrigerator.
For compounded tirzepatide users: The same 2.5 mg to 15 mg titration schedule applies to compounded tirzepatide from 503A or 503B pharmacies. With compounded vials you draw doses using an insulin syringe, which also allows non-standard increments. See the tirzepatide reconstitution guide for mixing and dosing instructions.
Side Effects by Dose Level
GI side effects are dose-dependent and most pronounced in the first 1–2 weeks after each escalation. The table below uses the Mounjaro prescribing information, Table 1 (pooled placebo-controlled trials in adults with type 2 diabetes). For full management strategies, see the tirzepatide side effects guide.
| Side Effect | 5 mg | 10 mg | 15 mg | Placebo |
|---|---|---|---|---|
| Nausea | 12% | 15% | 18% | 4% |
| Diarrhoea | 12% | 13% | 17% | 9% |
| Constipation | 6% | 6% | 7% | 1% |
| Vomiting | 5% | 5% | 9% | 2% |
| Decreased appetite | 5% | 10% | 11% | 1% |
Source: Mounjaro prescribing information, Table 1 (pooled placebo-controlled trials in adults with type 2 diabetes). In the separate Zepbound weight-management trials, nausea was 25-29%; the trials are not directly comparable.
Management tip: Most GI side effects are transient and resolve within 2–4 weeks of staying at a stable dose. If side effects are intolerable, your prescriber may hold the current dose for an additional 4 weeks rather than escalating. There is no clinical benefit to rushing the titration pace.
T2D-specific caution: Hypoglycemia risk with sulphonylureas. When Mounjaro is used in combination with insulin secretagogues such as sulphonylureas, the risk of hypoglycemia increases. The Mounjaro prescribing information recommends that prescribers consider reducing the sulphonylurea dose when initiating Mounjaro. This does not apply when Mounjaro is used as monotherapy; it does not cause hypoglycemia on its own due to its glucose-dependent mechanism.
Mounjaro Dosing in Special Populations
All figures below come from the Mounjaro prescribing information. Most patients don't need dose adjustments.
- Renal impairment (mild to moderate): No dose adjustment is required. Limited data exist for severe renal impairment; use with caution in that population. Source: Mounjaro PI.
- Hepatic impairment: No dose adjustment is recommended based on current prescribing information.
- Elderly patients (65+): No dose adjustment required. SURPASS clinical trials included patients 65 years and older. Tolerability was consistent with the overall trial population.
- Missed dose (per Mounjaro PI): If fewer than 4 days (96 hours) have passed since the scheduled injection day, take the missed dose as soon as possible. If more than 4 days have passed, skip the missed dose and resume the regular weekly schedule on the next scheduled day. Do not take two doses within 4 days of each other.
How to Use This Mounjaro Dosage Chart
- Count your weeks: Identify the number of weeks since your first Mounjaro injection. Match that to the dose column above.
- Confirm your dose: Cross-check that your KwikPen strength matches the chart. If your prescriber has adjusted your pace, follow their instructions.
- Track glycemic response: Log your fasting blood glucose and HbA1c readings between visits. Bring this log to your next appointment. If HbA1c targets are not met, your prescriber may advance the dose sooner.
- Prepare for each escalation: GI side effects typically peak in days 2–4 after each new dose. Eat smaller meals, avoid high-fat foods on injection day, and keep hydration up.
- Visualise your drug levels: Use the tirzepatide pharmacokinetic calculator to see how drug levels build and stabilise across your titration schedule. Mounjaro has an approximate 5-day half-life and reaches steady state in about 4 weeks at each dose level (Mounjaro label).
Visualise Your Mounjaro Drug Levels
The free tirzepatide pharmacokinetic calculator shows peak and trough drug levels across your full schedule. See exactly how levels build dose by dose and when you hit steady state.
Open Mounjaro Calculator →Tirzepatide Dosing Guide: A Prescribing Doctor Explains
Dr. Sasson from Lighthouse Weight Loss covers tirzepatide dosing from a prescriber's perspective: when to escalate, when to hold a dose, and what each tier actually feels like for patients.
Frequently Asked Questions
What is the starting dose of Mounjaro?
The starting dose of Mounjaro is 2.5 mg once weekly for 4 weeks. This dose is sub-therapeutic, meaning it does not yet lower blood sugar significantly. It is designed to let the body adjust to the medication and reduce gastrointestinal side effects before moving to the first therapeutic dose of 5 mg.
What doses does Mounjaro come in?
Mounjaro comes in six dose strengths: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg, each as a single-dose KwikPen. However, only three are true maintenance doses: 5 mg, 10 mg, and 15 mg. The others (2.5 mg, 7.5 mg, 12.5 mg) are titration stepping-stones to reduce side effects.
How long do you stay at each Mounjaro dose?
Each Mounjaro dose level is held for a minimum of 4 weeks before increasing. If additional glycemic control is needed, your prescriber may increase the dose. If side effects are significant, your prescriber may extend the current level for another 4 weeks. Total time to reach 15 mg is approximately 20 weeks.
What is the maximum dose of Mounjaro?
The maximum approved dose of Mounjaro is 15 mg once weekly. In SURPASS-1, the 15 mg dose produced the greatest HbA1c reduction (-2.07% vs placebo) and, separately, 20.9% mean body weight loss over 72 weeks in SURMOUNT-1. Not all T2D patients need to reach the maximum dose.
What is Mounjaro used for?
Mounjaro (tirzepatide) is FDA-approved as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. It is not approved for weight loss under the Mounjaro brand. Zepbound is the same molecule with a separate FDA indication for chronic weight management, approved November 2023.
Is Mounjaro the same as tirzepatide?
Yes. Mounjaro is a brand name for tirzepatide, a dual GLP-1 and GIP receptor agonist made by Eli Lilly. Mounjaro is the T2D indication; Zepbound is the same molecule approved for weight management. The dosing protocol, dose strengths, and injection device are identical across both brands.
What is the maintenance dose for Mounjaro?
The FDA-approved maintenance doses for Mounjaro are 5 mg, 10 mg, and 15 mg once weekly. Your prescriber chooses your maintenance dose based on your glycemic response and tolerability. Many T2D patients achieve good control at 5 mg or 10 mg without needing to reach the 15 mg maximum.
What happens if I miss a Mounjaro dose?
Per the Mounjaro prescribing information: if fewer than 4 days (96 hours) have passed since the scheduled injection, take the missed dose as soon as possible. If more than 4 days have passed, skip the missed dose and resume your regular weekly schedule. Do not take two doses within 4 days of each other.
How does Mounjaro lower blood sugar?
Mounjaro activates two receptors: GLP-1 and GIP. It stimulates insulin release in a glucose-dependent way (only when blood sugar is elevated), suppresses glucagon to reduce liver glucose output, and slows gastric emptying to blunt post-meal blood sugar rises. In SURPASS-1, the 15 mg dose reduced HbA1c by 2.07 percentage points vs placebo.
Does Mounjaro cause weight loss?
Yes, as a significant secondary benefit. In SURMOUNT-1 (obesity population, 72 weeks), tirzepatide 15 mg produced 20.9% average weight loss. T2D patients also see meaningful weight loss on Mounjaro, though typically somewhat less than obesity-primary trials due to different metabolic profiles. Weight loss is secondary; Mounjaro's primary T2D indication is glycemic control.
How long does it take for Mounjaro to work?
Glycemic effects begin at the first therapeutic dose (5 mg, weeks 5–8). Noticeable HbA1c improvements are typically seen by weeks 12–16. Mounjaro reaches steady-state blood levels in about 4 weeks at any given dose, given a half-life of approximately 5 days. Full titration to the maintenance dose takes 12–20 weeks.
Can I use this dosage chart for compounded tirzepatide?
Yes. The titration protocol is identical for brand-name Mounjaro KwikPens and compounded tirzepatide from 503A or 503B pharmacies. With compounded vials, you draw doses with an insulin syringe, which also allows non-standard increments (e.g., 3 mg or 6 mg). Consult your prescriber. See the tirzepatide reconstitution guide for mixing instructions.
Track Your Mounjaro Schedule
The free GLP3Planner calculator models your tirzepatide drug levels week by week, showing how levels build during titration and stabilise at steady state. No account needed.
References
- Eli Lilly and Company. Mounjaro (tirzepatide) Prescribing Information. Rev. 2024. FDA Label
- Rosenstock J, Wysham C, Frías 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): a double-blind, randomised, phase 3 trial. Lancet. 2021;398(10295):143-155. doi:10.1016/S0140-6736(21)01324-6. PubMed
- Frías JP, Davies MJ, Rosenstock J, et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2). N Engl J Med. 2021;385(6):503-515. doi:10.1056/NEJMoa2107519. PubMed
- Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). N Engl J Med. 2022;387(3):205-216. doi:10.1056/NEJMoa2206038. PubMed
- Garvey WT, Frias JP, Jastreboff AM, et al. Tirzepatide once weekly for the treatment of obesity in people with type 2 diabetes (SURMOUNT-2). Lancet. 2023;402(10402):613-626. doi:10.1016/S0140-6736(23)01200-X. PubMed
- ZEPBOUND (tirzepatide) prescribing information, Section 6.1, Table 1. Eli Lilly and Company; DailyMed. DailyMed
Related Resources
Tirzepatide Hub
Complete tirzepatide resource: mechanism, dosing, side effects, and tools.
Tirzepatide Dosage Chart
The Zepbound weight management dosage chart with SURMOUNT trial data and printable schedule.
Complete Tirzepatide Dosing Guide
In-depth dosing protocols, pharmacokinetics, and clinical trial summaries.
Tirzepatide Side Effects
Common and rare side effects with dose-by-dose breakdown and management strategies.
Microdosing Tirzepatide
Split dosing strategies for reducing side effects while maintaining therapeutic levels.
Tirzepatide Reconstitution Guide
Mixing compounded tirzepatide with BAC water and calculating insulin syringe volumes.
Medical Disclaimer: This dosage chart is for informational and reference purposes only. It does not constitute medical advice, diagnosis, or treatment. Always follow your prescriber's instructions, which may differ from the standard titration schedule based on your individual clinical response, comorbidities, and tolerability. Individual dosing varies. If you experience serious side effects or symptoms of hypoglycemia, contact your prescriber promptly.