Switching between Mounjaro and Wegovy

Modified on Thu, 2 Jul at 5:22 PM

Our doctors can support a switch from Mounjaro to Wegovy or from Wegovy to Mounjaro, as long as you meet the clinical criteria. Switching always involves a washout period between the two medications, and (if switching to Mounjaro) restarting at the lowest dose of 2.5mg. Eligibility, your current strength, and how well you have tolerated your current medication all affect how the switch is managed.

Who this applies to

This article applies to patients currently taking either Mounjaro or Wegovy who want to switch to the other medication. You either need to be a current patient of ours with a BMI of 25 or above to be eligible, or if moving from another provider have a BMI of 30 or over (or 27 with one or more co-morbidities). If you are an existing patient and your BMI has dropped below 30, switching to an "equivalent" dose is unlicensed and you will be notified of this by the prescriber.

Before you switch: what we need to know

When you place your order, the doctors will need:

  • Your current weight and height to calculate your BMI. You can use the NHS BMI calculator to work this out.
  • The strength you are currently on.
  • How long you have been on that strength.
  • Whether you have experienced side effects, whether they are still ongoing, and how manageable they are.

The washout period

Switching from one medication to the other requires a washout period between stopping one and starting the other. How long depends on your current strength, how long you have been on it, and your side effect history. The doctors will confirm the washout length when they review your order.

If you are switching from Mounjaro to Wegovy, you have two options once your washout is complete: you can switch straight to an equivalent strength of Wegovy without titrating down, or you can titrate down first if you would prefer to take it more gradually. Titrating down (with a minimum of one month on each strength before going down) remains the safest approach if you are unsure but please note if your BMI drops below 25 during this time you will not be eligible to switch. 

Switching to Mounjaro

If you are switching from Wegovy to Mounjaro, you start at 2.5mg again, regardless of the strength you were on previously. Mounjaro and Wegovy have different active ingredients, so your body will need time to adjust.

Switching to Wegovy

If you are switching from Mounjaro to Wegovy, as long as you have no side effects, and complete the required washout period, you may switch to a set "equivalent" strength of Wegovy. The doctors will still assess this case on a case-by-case basis.

Mounjaro to Wegovy dose conversion

Current Mounjaro doseRecommended Wegovy dose
2.5 mg0.25 mg
5 mg0.5 mg
7.5 mg1 mg
10 mg1 mg
12.5 mg1.7 mg
15 mg1.7 mg

Lifestyle habits to have in place

When you switch, strengthen the habits that support the medication: at least 3 litres of water a day, eating little and often, and regular movement. Switching can be a moment when side effects appear, and good habits reduce them.

Common scenarios

  • You have been on Wegovy for several months and want to try Mounjaro. You will need to confirm your BMI, strength, side effect history, and consent to the washout period (2 weeks if no side effects but 4 weeks if you have experienced side effects).
  • You have been on Mounjaro and your side effects are too much. Switching to Wegovy may be an option. In this case, you will need a longer washout period of 2 weeks rather than 7 days, so your body has time to recover before starting the new medication.
  • Your BMI has dropped below 30 and you want to continue switching. This is an unlicensed use, and you will be notified of this by the prescriber.

What to do next

To request a switch, place a new order for the medication you want to switch to and complete the consultation in full. There is a question on the consultation about switching; answer it with the details listed above. The doctors will review your request and confirm the washout period and starting dose.

You can read more about the differences between the two medications in our blog: https://www.oxfordonlinepharmacy.co.uk/blog/wegovy-vs-mounjaro-what-are-the-differences


Still need help?

See our Contact us article for the best way to reach our team.

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