Mounjaro shortage update: what the current supply picture looks like

What the official supply record shows about Mounjaro shortages

The MHRA and DHSC have maintained active oversight of tirzepatide supply since the medicine was licensed in the UK for weight management in late 2023. During 2024, several doses appeared on the DHSC's medicine supply notifications list, with lower strengths recovering faster than the 10mg, 12.5mg and 15mg pens. Eli Lilly, which manufactures Mounjaro, has expanded production capacity, and by mid-2025 the formal shortage notifications had eased for most strengths. That said, the question of whether a shortage still exists has no single answer: it depends on the dose, the individual pharmacy's supplier relationships, and real-time demand in any given week.

The NICE appraisal of tirzepatide, published in December 2024 and updated in September 2025 (NICE TA1026), recommended the medicine for NHS use in adults with a BMI of 35 or above plus at least one weight-related condition. That recommendation triggered a step-change in demand. NHS England's phased rollout began in June 2025, with a second cohort activated in June 2026, and each new cohort puts additional pressure on the same licensed supply chain. Private demand has also grown. The net effect is that even where no formal shortage exists, some pharmacies are managing stock week to week rather than holding deep reserves.

For the most current UK-specific picture, the DHSC publishes its medicine supply tool on GOV.UK; that is the authoritative source for any live shortage declaration, and it is updated more frequently than any third-party aggregator.

Which doses have been tightest, and why the titration schedule matters

Tirzepatide is prescribed at six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg. Treatment starts at 2.5mg because the body needs time to adjust before the dose is increased, typically in four-week steps under prescriber guidance. This titration ladder means a large cohort of patients who started treatment at similar times will all be moving toward higher doses at roughly similar intervals.

The practical consequence is that demand for 10mg, 12.5mg and 15mg pens has historically peaked sharply, while 2.5mg and 5mg have generally remained more available. If you want to understand why Mounjaro shortages tend to cluster at the top of the dose range, this cohort-movement effect is a large part of the answer. Lilly has said publicly that its manufacturing investments are specifically aimed at the higher-dose pens, but production lead times for complex biologic medicines are long.

One thing worth knowing: because every legitimate supply chain in the UK runs through a GPhC-registered pharmacy, a pharmacy that has strong, direct relationships with authorised Eli Lilly distributors will resolve short-term gaps faster than one routing through secondary wholesalers. That supply-chain depth is part of what separates regulated online pharmacies from the unverified sellers who have been advertising tirzepatide on social media.

The counterfeit risk that a shortage creates

Supply gaps create the conditions in which fake products thrive. The MHRA has been explicit about this: when legitimate channels run short, some people turn to social-media sellers or websites that offer pens without any clinical assessment. In 2025 alone, enforcement teams intercepted around 20 million doses of illegally traded weight-loss medicines, worth an estimated £45 million, and a counterfeit tirzepatide manufacturing site was raided in Northampton. Some of the fake pens seized in earlier operations contained insulin rather than the labelled medicine — a potentially life-threatening substitution.

The MHRA's guidance is straightforward: report any suspect sellers via the Yellow Card scheme, and only obtain prescription medicines through a pharmacy you can verify on the GPhC register. You can check any online pharmacy's registration at pharmacyregulation.org. If a seller is advertising Mounjaro without requiring a prescription or clinical assessment, that is a red flag, not a shortcut. The medicine itself may be counterfeit, underdosed, or stored incorrectly.

For context on how the tirzepatide shortage compares to earlier GLP-1 supply disruptions, the pattern is familiar: semaglutide experienced similar pressure when Wegovy launched. The difference is that the enforcement response has scaled up considerably since then.

What to do right now if your supply is interrupted

If you are currently on Mounjaro and your pharmacy cannot fulfil a dose, the first step is to contact your prescriber before missing an injection or switching to a different dose yourself. The timing of doses and any gap management is a clinical decision, not one to navigate from a forum. Your prescriber may advise waiting a short period, maintaining your current dose rather than escalating, or (in some circumstances) a temporary adjustment. The NHS tirzepatide patient information page is worth reading alongside your Patient Information Leaflet.

If you are considering starting treatment and are concerned about ongoing availability, a consultation is still the right first step. Suitability is assessed individually, and a prescriber can give you a realistic picture of what to expect at each stage of the titration schedule. You can also read more about the latest Mounjaro supply developments or explore other weight-loss treatment options if your circumstances have changed. For a broader look at how UK Mounjaro shortages have developed over time, that context can help set expectations. On cost, our Mounjaro price comparison page explains what a legitimate private prescription typically includes. When you are ready to speak with a prescriber, you can start your free consultation at our treatment page.