Since becoming FDA-approved in 2022, Mounjaro’s popularity has snowballed, flying off the shelves in America. And it has recently launched in the UK, where there are fewer supply challenges that currently being experienced in the US, leading to loads of excitement from UK patients who have previously struggled with their weight.

Mounjaro is similar to weight loss medications like Ozempic and Wegovy, but it contains a slightly different compound and may be more effective for both blood sugar control and weight loss.

The first three strengths of Mounjaro are currently available in the UK, and the remaining three are expected to become available in the coming months. Here's everything you need to know about Mounjaro and its availability in the UK.

What is Mounjaro? 

Before we dive into the availability of Mounjaro, let’s first understand exactly what it is and how it works. 

As mentioned, Mounjaro is a medication prescribed for patients with type 2 diabetes and/or obesity alongside diet and exercise. Mounjaro specifically is the brand name for tirzepatide, which is dual glucose-dependent insulinotropic polypeptide (GIP) and GLP-1. GLP-1 and GIP medications  increase the production of insulin, helping manage your blood sugar levels and regulate appetite. In the UK, Mounjaro is taken as a weekly injection via a multi-use 'KwikPen" which lasts for four injections.

We’ve written previously about how semaglutide (drugs like Ozempic and Wegovy) works, and tirzepatide has very similar effects. As a GLP-1, it helps decrease how much food you eat by mimicking a hormone which is released after you’ve eaten (therefore making you feel fuller for longer).[1]

GIP has similar effects, and whilst it's not fully understood exactly how these two different compounds work, the combination of the two seems to be very effective for appetite suppression and therefore weight loss.[2]

Initial trials in patients with type 2 diabetes suggest that Mounjaro (tirzepatide) may be more effective for weight loss than semaglutide, with tirzepatide resulting in a weight loss of 17.8% compared with 12.4% for semaglutide.[3]

When will Mounjaro be available in the UK? 

Mounjaro launched in the UK in February 2024.

The National Centre for Health Care and Excellence (NICE) has already evaluated and recommended tirzepatide for type 2 diabetes[4]. A similar evaluation is underway for obesity, and publication is expected later this year.[5] It's important to note that NICE evaluation is not prohibitive to patients accessing Mounjaro privately in the UK—NICE guidance rather impacts whether the NHS will pay for treatments on behalf of patients. Eligible patients can already purchase Mounjaro privately in the UK, as it has been approved by the MHRA.

The impact of the medication in the US will be watched closely by the UK regulators. Given their receptiveness towards Ozempic (already approved and available on the NHS) and Wegovy (set to launch as a trial), there’s good indications of their interest in GLP-1s and their effectiveness. Some are even saying that tirzepatide may be included in the government’s £40m pilot for these medications. 

When will the different doses of Mounjaro be available in the UK?

As of late April 2024, Mounjaro 2.5mg, 5mg, and 7.5mg are available for purchase in the UK.

Assuming that Eli Lilly, the manufacturer of Mounjaro, follows the same pattern as previous months, it is likely that 10mg becomes available in mid-May, 12.5mg in mid-June, and 15mg in mid-July. However it's difficult to know until the higher doses launch, as these medications have seen significant supply chain delays in other countries.