UK switching guide
Switching from Wegovy to Mounjaro: what to know before you move
Thinking about moving from Wegovy to Mounjaro? This guide keeps the focus on the actual switch: timing, prescriber checks, UK eligibility, the new Wegovy 7.2 mg issue and the questions to ask before you start.
Yes, many patients can be assessed for Mounjaro after Wegovy, but your prescriber should decide the timing. A common private-provider approach is to leave about a week after the last Wegovy injection, but the right plan can vary a lot depending on your final Wegovy dose, side effects, BMI category, other medicines and pregnancy or contraception needs.
Start with the reason for switching
People usually look at Mounjaro after Wegovy because appetite suppression feels weaker than expected, weight loss has slowed, side effects are awkward, supply has changed, or the prescriber thinks another option is clinically reasonable.
Wegovy is no longer doing enough
If appetite, cravings or weight loss have plateaued, your prescriber may review whether changing medicine, changing dose, pausing escalation, or staying put is the better route.
Side effects matter
Nausea, vomiting, constipation, reflux or gallbladder-type symptoms can affect the timing of any move. A new medicine is not a shortcut around unresolved side effects.
Criteria are not identical everywhere
The licence, NICE recommendations, NHS rollout and private provider policies can all be different. That is why one patient may be accepted while another similar-looking patient is asked for more information.
How long after Wegovy can you start Mounjaro?
This is the key practical question. Some UK private pathways describe a gap of around one week, but the safer wording is: your prescriber decides the start date after checking your last dose, symptoms and risk factors.
A one-week gap is commonly mentioned
You may see private services talk about starting Mounjaro roughly seven days after the last Wegovy injection. That can make sense as a practical weekly-injection pathway for some people, but it is not a universal rule for every patient.
Wegovy can remain in the body for weeks
The official Wegovy SmPC says semaglutide has an elimination half-life of about one week and can remain in circulation for around seven weeks after the last 2.4 mg dose. That does not mean everyone must wait seven weeks, but it explains why prescribers need context.
Wegovy now goes up to 7.2 mg in the UK, but not for every Wegovy patient
Old switching articles often compare Mounjaro with Wegovy 2.4 mg. UK guidance has moved on: MHRA approved Wegovy up to 7.2 mg/week for adult patients with obesity. That matters when someone is comparing whether to stay on Wegovy, move up, or ask about Mounjaro.
MHRA says the 7.2 mg position “does not apply to overweight patients with a BMI of less than 30kg/m²”.
In practice, that means a patient with BMI 27 to under 30 using Wegovy under the overweight-with-comorbidity route should not assume the 7.2 mg obesity-only dose is available to them. A prescriber should explain the route that applies.
What your prescriber should check before the move
This section is the heart of the page: what matters when someone is actively looking to move from Wegovy to Mounjaro.
Your last Wegovy dose and date
There is a big difference between stopping at 0.5 mg, 1.7 mg, 2.4 mg or 7.2 mg. Your final dose and the date of your last injection shape the switching discussion.
Your side-effect pattern
Ongoing vomiting, severe nausea, dehydration, abdominal pain, gallbladder symptoms or suspected pancreatitis need medical review. The switch should not be used to mask a problem.
Your BMI route and weight-related conditions
Mounjaro’s UK licence includes obesity and overweight with at least one weight-related condition, but NHS eligibility and private prescribing policies can be stricter or phased differently.
Diabetes medicines and low-blood-sugar risk
If you use insulin or sulfonylureas, the prescriber may need to adjust treatment because GLP-1/GIP medicines can change glucose control and hypoglycaemia risk when combined with some diabetes medicines.
Pregnancy plans and contraception
Mounjaro can affect oral contraceptive absorption around treatment start and dose increases. If this is relevant, ask about non-oral contraception or added barrier contraception during the advised period.
What the official evidence actually says
This is not pharmacy sales copy. These points are pulled from official UK medicine information, MHRA announcements, NICE and NHS England pages.
| Question | Wegovy | Mounjaro | Switching meaning |
|---|---|---|---|
| Starting or restarting pattern | Wegovy starts at 0.25 mg weekly and escalates gradually. For adult patients with obesity, 7.2 mg can be used if needed after 2.4 mg. | Mounjaro starts at 2.5 mg weekly, then 5 mg after 4 weeks, with later increases if needed and tolerated. | The prescriber will normally focus on a safe Mounjaro start, your recent Wegovy exposure and current symptoms. |
| New UK 7.2 mg context | 7.2 mg is an obesity-only Wegovy route. MHRA says it does not apply to overweight patients with BMI under 30 kg/m². | Mounjaro’s licensed weight-management route includes BMI ≥30, or BMI ≥27 to <30 with at least one weight-related comorbidity. | Someone under BMI 30 may still be assessed differently depending on medicine, indication, provider policy and NHS/private route. |
| Clinical trial signal | STEP UP data in the SmPC reports greater weight reduction with semaglutide 7.2 mg than 2.4 mg at 72 weeks. | SURMOUNT-5 in the Mounjaro SmPC reports greater mean weight reduction with tirzepatide than semaglutide 1.7/2.4 mg at 72 weeks. | Old “Mounjaro vs Wegovy” claims often compare against 2.4 mg Wegovy, not the newest 7.2 mg UK context. |
| Contraception | Wegovy is not usually the medicine with the specific oral-contraception absorption warning. | Mounjaro has specific contraception advice because delayed gastric emptying may affect oral contraceptives, especially after starting and dose increases. | This is one of the most important practical checks for women of childbearing potential. |
| Review and stopping decisions | Official product information includes review points around response and tolerability. | NICE and the SmPC include review of response, tolerability and whether to continue if weight loss is below expected thresholds. | A good prescriber should review progress rather than simply escalating forever. |
Switching checklist: what should you ask?
Use this to prepare for a prescriber review. It does not diagnose, approve treatment or replace medical advice.
Your Wegovy situation
Choose the closest option and the checklist will update.
Your discussion points
Give your prescriber your last Wegovy dose, last injection date and current symptoms.
- Ask whether a one-week gap is suitable for your exact situation.
- Ask what Mounjaro starting dose they recommend and why.
- Ask what side effects should trigger urgent review.
Compare Mounjaro safely
Use Monj to understand pricing, provider checks and the evidence behind listings before choosing where to request treatment.
Understand Wegovy first
If you are still deciding whether to stay on Wegovy, increase dose, or ask about moving, use iGovy for Wegovy-focused context.
Switching is about timing, suitability and follow-up
A subtle visual summary sits near the bottom of the page. It stays contained, loads lazily and remains fully visible without cropping.
Switching from Wegovy to Mounjaro: FAQs
Short answers for the questions people usually search before asking a prescriber.
Can I switch from Wegovy to Mounjaro?
Many people can be assessed for Mounjaro after Wegovy, but the prescriber needs your last Wegovy dose, last injection date, BMI, side-effect history, medical conditions and other medicines before advising on timing.
Is a one-week washout always enough?
No single gap fits everyone. A one-week gap is commonly seen in private switching pathways, but your prescriber may advise differently if you were on a higher dose, had side effects, use diabetes medicines, or have other risks.
Does the new Wegovy 7.2 mg dose matter?
Yes. Wegovy can now go up to 7.2 mg/week in the UK for adult patients with obesity, but MHRA says that does not apply to overweight patients with BMI under 30 kg/m². This can affect the discussion if you are comparing staying on Wegovy with moving to Mounjaro.
Will I start Mounjaro at the same strength as my Wegovy dose?
Mounjaro has its own starting and escalation schedule. The UK SmPC says tirzepatide starts at 2.5 mg once weekly, then moves to 5 mg after 4 weeks, with later 2.5 mg increases after at least 4 weeks on the current dose if needed and tolerated.
Why do different providers give different answers?
Because eligibility can depend on the medicine licence, NICE guidance, NHS rollout rules, private clinical policy, your BMI route, comorbidities, side effects and risk profile. Different criteria do not automatically mean one provider is wrong.
What should I tell the prescriber?
Give the last Wegovy dose and date, your current weight and height, your reason for switching, side effects, medical conditions, diabetes medicines, pregnancy plans, contraception and any previous problems with GLP-1 medicines.
Official sources used
No pharmacy outbound links. These are regulator, NICE, NHS and official medicines-information sources, plus Monj and iGovy internal links.
Wegovy 7.2 mg approval
Official UK announcement on the higher semaglutide dose for adult patients with obesity.
Single-dose 7.2 mg pen
Official April 2026 update on the single-dose Wegovy 7.2 mg pen.
Wegovy product information
Official Wegovy dosing, pharmacokinetics and trial data via medicines.org.uk.
Mounjaro product information
Official Mounjaro dosing, escalation, contraception and clinical-study information.
Tirzepatide guidance
NICE guidance for tirzepatide in managing overweight and obesity.
NHS rollout context
Eligibility and phased commissioning context for NHS access to tirzepatide.
Yellow Card
Report suspected side effects to the MHRA Yellow Card scheme.
Monj and iGovy
Independent UK patient information and price/transparency tools.