Mounjaro Price Increases – How to Safely Switch from Mounjaro to Wegovy in 7 days

Why switch?

People move from Mounjaro (tirzepatide) to Wegovy (semaglutide) for many reasons such as better side‑effect profile, personal preference, supply, or cost (recent UK price changes have prompted many to consider alternatives).

From 1 September 2025, Eli Lilly is increasing UK list prices for Mounjaro, with some doses rising by up to 170%. The 15 mg strength will go from £122 to £330 per month. Lilly says the change is to “align prices across developed markets.” NHS supply is covered by separate arrangements, so the increase primarily affects private patients.

Lilly also linked the move to the Trump administration’s drug-pricing agenda, which targets lower prices in the U.S. while tolerating higher prices elsewhere to keep overall revenues balanced.

Whatever the rationale, the announcement has understandably left Mounjaro users anxious about access. For those unable to absorb the higher costs, this guide presents Wegovy as a potentially more affordable alternative and explains how to switch safely and effectively, without interrupting treatment.

Wegovy Titration Calculator for Switching from Mounjaro

Select your most recent weekly Mounjaro dose to view your recommended Wegovy schedule. Please note this is for guidance purposes only. Your NowPatient Specialist Weight Loss Clinician will take into account all relevant factors when deciding your initial switching dose.

How these medicines differ

• Mounjaro (tirzepatide): Dual GIP/GLP‑1 receptor agonist; weekly auto‑injector KwikPen typically titrated as follows:
  • 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15 mg.
• Wegovy (semaglutide): GLP‑1 receptor agonist; weekly auto‑injector FlexTouch Pen titrated as follows:
  • 0.25mg → 0.5mg → 1.0mg → 1.7mg → 2.4 mg.
• Mounjaro and Wegovy are NOT dose‑equivalent. Switching from Mounjaro (tirzepatide) to Wegovy (semaglutide) requires careful consideration, as the two medications have different potencies and dosing schedules. A short break and a tailored re‑start dose.

Am I eligible to switch to Wegovy with NowPatient?

You’ll usually qualify if you’re ≥18 years and either BMI ≥30, or BMI ≥27 with a weight‑related condition such as:

• High blood pressure
• Dyslipidaemia
• Sleep apnoea

Before a switch can be approved, a NowPatient weight specialist clinician must confirm Wegovy is safe and suitable for you (e.g., no allergy to semaglutide, not pregnant/breast‑feeding, and no relevant contraindications or interactions).

The safest way to switch to Wegovy in 7 days (step‑by‑step)

Switch to Wegovy in 7 Days, with NowPatient

1. Book an online consultation with one of our weight specialist clinicians
2. During the consultation, the clinician will review your information and assess if switching from Mounjaro to Wegovy is safe for you
3. If approved, the clinician will authorise a prescription
4. Stop taking Mounjaro as instructed
5. Allow at least seven days for Mounjaro to fully clear from your system. Do not overlap the two medicines
6. Your prescription will be delivered discreetly to your door – store it in the fridge immediately
7. Begin your Wegovy treatment and continue your weight loss journey safely with NowPatient. Inject once weekly on the same day each week

What dose of Wegovy should I start on?

Your start dose depends on your last stable Mounjaro dose and how well you tolerated it.

The table below shows upper‑bound starting points used in practice; your clinician may begin lower (e.g., at 0.25 mg) to minimise side effects.

These are pragmatic upper bounds, not formal equivalence doses. Your prescriber may choose a lower starting dose based on your history and side‑effect tolerance.

Wegovy titration after the switch

A common schedule for an individual whose last stable dose of Mounjaro was 2.5mg (adjusted by clinician if advised):

Weeks 1–4: 0.25 mg weekly (or your clinician‑selected start dose)

Weeks 5–8: 0.5 mg weekly

Weeks 9–12: 1.0 mg weekly

Weeks 13–16: 1.7 mg weekly

Week 17 onward: 2.4 mg weekly (maintenance)

If you experience troublesome GI symptoms, pause at your current step for 2-4 extra weeks before increasing. If symptoms are severe, step down or hold and contact a clinician.

What to expect when switching

• No “withdrawal”: you shouldn’t get withdrawal symptoms from stopping Mounjaro. Some people notice more appetite during the gap or on lower early Wegovy doses; this usually settles as you titrate.
• Side effects: nausea, vomiting, diarrhoea/constipation, tummy pain, headache, fatigue can occur (often when first starting or increasing the dose). Most are mild and settle.
• When to get help (red flags): severe, persistent abdominal pain (especially with vomiting), signs of pancreatitis or gallstones, persistent vomiting/dehydration, allergic‑type reactions, vision changes in diabetes, or suspected pregnancy.

Tips to reduce side effects

• Eat slowly
• Consume smaller, lower‑fat meals
• Limit alcohol
• Hydrate
• Consider simple anti‑sickness or constipation remedies if advised by our specialist weight loss clinician
• If side effects persist, discuss holding at your current dose longer with our specialist weight loss clinician

Practical differences you’ll notice

• Pen priming: Wegovy pens are primed before the first use only; Mounjaro requires priming before every injection.
• Storage: Keep both refrigerated before first use. After opening, Mounjaro can be stored at room temperature for up to 30 days; Wegovy for up to 42 days. Always follow the leaflet for the exact limits.
• Cardiovascular benefit: Wegovy is currently the only weight‑management injection licensed to reduce cardiovascular event risk in people with obesity and heart disease.

Summary

A safe switching plan looks like this:

Finish Mounjaro → wait 7 days → start Wegovy at a clinician-approved dose → titrate steadily with clinical oversight. NowPatient streamlines the process with prescribing, delivery, and ongoing support so you can continue losing weight safely.

Use the NowPatient Wegovy Titration Calculator to see what your switching plan will look like.

Frequently Asked Questions

Can I start at a higher Wegovy dose because I was on high‑dose Mounjaro?

Possibly. Many people still begin at 0.25–0.5 mg to minimise GI symptoms; some may start at 1.0 mg under clinician guidance. Never exceed your prescriber’s plan.

Is a 7‑day gap enough?

In most cases, yes. Some clinicians prefer a longer washout (up to 30 days) to reduce overlap; your plan will be individualised.

Which has worse side effects?

Side‑effect profiles are similar but vary by person. If one medicine caused bothersome symptoms, you may tolerate the other better.

Will I gain weight during the switch?

Most people do not if they keep weekly dosing consistent and maintain healthy habits.

Can I switch back to Mounjaro later?

Yes, if your prescriber agrees it’s appropriate and safe. Do not overlap the two medicines.

How do I switch from Mounjaro 2.5mg to Wegovy?

How do I switch from Mounjaro 5mg to Wegovy?

How do I switch from Mounjaro 7.5mg to Wegovy?

How do I switch from Mounjaro 10mg to Wegovy?

How do I switch from Mounjaro 12.5mg to Wegovy?

How do I switch from Mounjaro 15mg to Wegovy?