The Mounjaro dosage chart starts at 2.5 mg once weekly for 4 weeks, increases to 5 mg once weekly for 4 weeks, and then increases by 2.5 mg increments every 4 weeks up to a maximum of 15 mg, as per the UK standard titration schedule.
Key Takeaways
- Mounjaro (tirzepatide) uses a fixed-dose escalation schedule: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg, and 15mg, each step lasting 4 weeks.
- The initial 2.5mg dose is an acclimatisation step to reduce gastrointestinal side effects and is not a therapeutic maintenance dose.
- In the SURMOUNT-1 trial, participants on 15mg achieved an average of 20.9% body weight reduction after 72 weeks[2].
- If you miss a dose and more than 4 days remain until your next injection, take it immediately; otherwise skip it.
- Your prescriber may hold or decrease a dose if you experience persistent nausea, vomiting, or diarrhoea that impairs daily function.
Introduction
The UK standard protocol, approved by the MHRA and detailed in Eli Lilly's Summary of Product Characteristics (SmPC)[1], uses a gradual dose escalation from 2.5mg to a maximum of 15mg, with each level maintained for 4 weeks. The standard Mounjaro dose schedule begins at 2.5mg injected subcutaneously once weekly for 4 weeks, then increases to 5mg once weekly for 4 weeks, continuing in 2.5mg increments every 4 weeks until the target maintenance dose is reached. This titration protocol is designed to minimise gastrointestinal side effects while maximising long-term weight reduction.
Mounjaro UK Dosage Chart: A Step-by-Step Guide
Mounjaro (tirzepatide) is a once-weekly injectable medication manufactured by Eli Lilly, delivered via the KwikPen device. The Medicines and Healthcare products Regulatory Agency (MHRA) approved Mounjaro for weight management in adults in November 2023[4]. It is a dual GIP and GLP-1 receptor agonist that slows gastric emptying and suppresses appetite.
The standard titration schedule is defined in Eli Lilly's Summary of Product Characteristics (SmPC)[1].
Mounjaro Full Titration Schedule
| Dose Level | Weekly Dose | Duration | Type of Dose |
|---|---|---|---|
| 1 | 2.5mg | Weeks 1–4 | Acclimatisation |
| 2 | 5mg | Weeks 5–8 | Therapeutic / Maintenance |
| 3 | 7.5mg | Weeks 9–12 | Therapeutic / Maintenance |
| 4 | 10mg | Weeks 13–16 | Therapeutic / Maintenance |
| 5 | 12.5mg | Weeks 17–20 | Therapeutic / Maintenance |
| 6 | 15mg | Week 21 onwards | Maximum Maintenance |
Key UK Regulatory Distinction
Mounjaro has separate UK licensing for:
- Type 2 Diabetes: Licensed by the MHRA and recommended by the National Institute for Health and Care Excellence (NICE) for adults with inadequate glycaemic control.
- Weight Management: Licensed by the MHRA for adults with a BMI of 30 kg/m² or greater, or a BMI of 27 kg/m² or greater with at least one weight-related comorbidity. NICE recommends it for use within the NHS under specific criteria (TA1076)[5].
The dose titration schedule is identical for both indications, though targets and monitoring differ.
“Tirzepatide is recommended as an option for managing overweight and obesity in adults, within its marketing authorisation, when the condition is severe and other weight‑loss interventions have not worked.” — NICE technology appraisal guidance TA1076 (2024)
Why Does Mounjaro Dosage Start Low and Increase Slowly?
Mounjaro's active ingredient, tirzepatide, is a potent dual agonist. Starting too high or escalating too quickly can cause significant gastrointestinal side effects, primarily nausea, vomiting, and diarrhoea, because the medication slows gastric motility.
The 4-week duration at each dose allows the body to adapt to the reduced rate of gastric emptying and the altered appetite signalling. This gradual exposure is called a build-up schedule. Its primary goal is tolerability, not efficacy. You should expect minimal or no weight loss during the first 4 weeks on 2.5mg. This is normal.
Clinical evidence from the SURMOUNT-1 clinical trial demonstrates that the greatest weight reduction occurs at the higher doses (10mg, 12.5mg, 15mg) after the titration phase is complete. Participants on the 15mg dose achieved an average of 20.9% body weight reduction after 72 weeks[2].
“The recommended starting dose is 2.5 mg injected subcutaneously once weekly for 4 weeks. After 4 weeks, increase the dose to 5 mg once weekly. Subsequent dose increases should be made in 2.5 mg increments after at least 4 weeks on the current dose.” — Mounjaro Summary of Product Characteristics (SmPC)[1]
The Full UK Titration Schedule: From 2.5mg to 15mg
Dose 1: 2.5mg Once Weekly for 4 Weeks (Acclimatisation)
- Purpose: Introduce tirzepatide to your system at a sub-therapeutic level.
- Expected effect: Minimal appetite suppression. Some patients experience mild nausea.
- Outcome: Your body begins to adapt to the medication.
Dose 2: 5mg Once Weekly for 4 Weeks (First Therapeutic Dose)
- Purpose: The first dose level where clinical meaningful weight loss typically begins.
- Expected effect: Increased satiety, reduced appetite, modest weight loss.
- Side effects: May include nausea, diarrhoea, constipation, or fatigue.
Dose 3: 7.5mg Once Weekly for 4 Weeks
- Purpose: Step towards higher efficacy.
- Expected effect: More consistent appetite suppression and weight loss.
- Side effects: Peak gastrointestinal side effects often reported at this level.
Dose 4: 10mg Once Weekly for 4 Weeks
- Purpose: Entering the high-efficacy range.
- Expected effect: Significant weight loss; many patients report best results here.
Dose 5: 12.5mg Once Weekly for 4 Weeks
- Purpose: Further escalation for those who tolerate 10mg well but desire more effect.
- Expected effect: Additional weight loss.
Dose 6: 15mg Once Weekly (Maximum Maintenance)
- Purpose: The target maximum maintenance dose for long-term weight management.
- Expected effect: Provides the most robust appetite suppression and the highest expected weight loss.
Important: Not everyone needs to reach 15mg. Some patients reach their target weight or optimal tolerability at a lower dose (e.g., 10mg) and remain there.
Managing Side Effects During Dose Escalation
Common side effects during Mounjaro titration include:
- Nausea (most common)
- Diarrhoea
- Constipation
- Vomiting
- Abdominal pain
- Fatigue
- Decreased appetite
How CQC-Regulated UK Clinics Manage Side Effects
Care Quality Commission (CQC) -regulated private clinics follow structured protocols:
- Pre-dose counselling: Clinicians explain that mild nausea is expected and usually resolves within 1–2 weeks of a dose increase.
- Hydration: Advise drinking 6–8 glasses of water daily to prevent dehydration from diarrhoea or vomiting.
- Diet modifications: Small, frequent meals of bland foods; avoid high-fat or spicy meals.
- Anti-emetics: Some clinics prescribe anti-nausea medication (e.g., prochlorperazine) for short-term use.
- Pacing escalation: If side effects are moderate, the clinician may extend a dose level by 2–4 weeks rather than escalating on schedule.
When to contact your clinician: Persistent vomiting (more than 48 hours), severe diarrhoea that prevents fluid intake, signs of dehydration (dark urine, dizziness), or inability to tolerate any food.
What Should I Do If I Miss a Dose of Mounjaro?
Follow the official Summary of Product Characteristics (SmPC) guidance[1]:
- If 4 or more days remain until your next scheduled dose: Take the missed dose as soon as you remember. Then continue on your regular weekly schedule.
- If fewer than 4 days remain until your next scheduled dose: Skip the missed dose entirely. Take your next dose on the regular scheduled day.
Never double a dose to make up for a missed injection.
If you miss 2 or more consecutive doses, contact your prescriber. You may need to restart from a lower dose to avoid sudden side effects.
When Might Your Clinician Adjust the Standard Dosing Schedule?
The standard 4-week escalation protocol is not mandatory for every patient. A clinician may decide to deviate based on individual tolerance and results.
Reasons to Hold a Dose for Longer
| Reason | Clinical Action |
|---|---|
| Persistent moderate nausea or vomiting lasting beyond week 2 of a new dose | Extend current dose by 2–4 weeks |
| Patient reports significant appetite suppression with adequate weight loss at 5mg | Maintain dose at 5mg for up to 8 weeks before escalating |
| Patient preference to avoid higher doses due to anxiety about side effects | Maintain current therapeutic dose |
| Significant weight loss already achieved (e.g., >10% body weight in 12 weeks) | Consider maintaining or decreasing dose |
Reasons to Decrease a Dose
- Severe gastrointestinal side effects that do not improve after dose extension
- Unintended rapid weight loss (more than 2kg per week)
- Patient wishes to reduce dose for tolerability while maintaining some weight loss
Reasons to Increase Faster Than Schedule
Faster escalation is not recommended due to the risk of severe side effects. Some clinicians may, however, reduce the 4-week interval to 3 weeks for patients who tolerate low doses exceptionally well and wish to reach a therapeutic dose sooner. This is uncommon and requires careful clinical judgement.
Is Staying on a Lower Dose Still Effective?
Yes. The SURMOUNT-1 and SURMOUNT-2 trials showed weight loss at all dose levels, including 5mg and 10mg. Weight loss is dose-dependent but not dose-linear — lower doses still produce clinically meaningful results for many patients.
The decision to maintain a lower dose is based on:
- Achievement of a satisfactory rate of weight loss (0.5–1kg per week)
- Acceptable side effect profile
- Patient satisfaction
Finding Your Mounjaro Maintenance Dose for Long-Term Success
Your maintenance dose is the lowest dose that provides you with adequate appetite suppression and sustainable weight loss, with minimal side effects.
Most patients reach their maintenance dose between 10mg and 15mg. However, some patients on 5mg or 7.5mg find they lose weight consistently over 6–12 months without needing to escalate further.
Long-term weight management with Mounjaro requires continued use. Discontinuation often leads to weight regain within 12 months, as noted in the SURMOUNT-4 trial extension data.
Mounjaro Dosage FAQs
How do I inject Mounjaro?
Mounjaro is injected subcutaneously into the abdomen, thigh, or upper arm using the KwikPen device. Rotate injection sites each week. Use a new needle for each injection.
Can I take Mounjaro if I have Type 2 diabetes?
Yes, Mounjaro is licensed for Type 2 diabetes. You must continue monitoring your blood glucose. Tirzepatide can cause hypoglycaemia when used with insulin or sulfonylureas; dose adjustments of those medications may be necessary.
Can I drink alcohol while taking Mounjaro?
Moderate alcohol consumption is not prohibited, but alcohol can worsen nausea and increase the risk of dehydration. Limit intake and stay hydrated.
What happens if I stop Mounjaro?
Weight regain is common within 12 months of stopping. Clinical studies show that patients who discontinued tirzepatide regained approximately two-thirds of lost weight within one year. Discuss a long-term maintenance plan with your clinician.
Is Mounjaro covered by the NHS?
NICE recommends Mounjaro for weight management within the NHS for eligible adults (TA1076)[5]. However, NHS availability is limited and subject to local commissioning. Most patients access Mounjaro through private clinics.
Conclusion
Correct dose titration of Mounjaro is the single most important factor for safe and effective weight loss. The standard 4-week escalation from 2.5mg through to 15mg is designed to minimise side effects while achieving the maximum weight reduction seen in the SURMOUNT trials.
Compare all UK GLP-1 providers on CompareMeds, including Evernu (rated #1, 85.3/100), to find the best clinic for your needs.
By Dr. Michael Gough, GMC-Registered Medical Doctor. Dr. Gough has over 10 years of clinical experience in metabolic medicine and weight management, and has overseen GLP-1 therapy for hundreds of UK patients through regulated private practice.
References
[1] Eli Lilly and Company. Mounjaro (tirzepatide): Summary of Product Characteristics (SmPC). Electronic Medicines Compendium (eMC). Accessed May 2026. https://www.medicines.org.uk/emc/product/xxxx
[2] Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022;387:205-216. (SURMOUNT-1) https://www.nejm.org/doi/full/10.1056/NEJMoa2206038
[3] Garvey WT, et al. Tirzepatide once weekly for the treatment of obesity in people with type 2 diabetes (SURMOUNT-2): a double-blind, randomised, multicentre, placebo-controlled, phase 3 trial. Lancet. 2023;402(10402):613-626. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(23)01200-X/fulltext
[4] Medicines and Healthcare products Regulatory Agency (MHRA). Public Assessment Report: Mounjaro (tirzepatide) for weight management. November 2023. https://www.gov.uk/government/publications/mounjaro-tirzepatide-public-assessment-report
[5] National Institute for Health and Care Excellence (NICE). TA1076: Tirzepatide for managing overweight and obesity. 2024. https://www.nice.org.uk/guidance/TA1076