Since Mounjaro (tirzepatide) became available in the UK, supply has been a persistent concern for patients. Demand has consistently outstripped initial supply forecasts, leading to intermittent shortages across various dose strengths. Here is the latest update for 2025.
Current Supply Status
As of mid-2025, Eli Lilly has significantly expanded manufacturing capacity for tirzepatide, investing billions globally in new production facilities. The UK supply situation has improved compared to 2024, but intermittent shortages of specific dose strengths continue to occur. The most commonly affected doses are the mid-range strengths (7.5 mg and 10 mg), as these are the doses most patients settle on for maintenance.
Why Shortages Happen
Several factors contribute to ongoing supply challenges:
- Unprecedented global demand — weight loss medications have seen extraordinary uptake across multiple markets simultaneously
- Complex manufacturing — biological peptide medications require specialised production facilities and lengthy manufacturing timelines
- Dose titration patterns — as more patients reach maintenance doses, demand shifts between dose strengths unpredictably
- Regulatory quality controls — the MHRA maintains strict quality standards that cannot be compromised to increase output
How to Manage Supply Uncertainty
UK patients can take several practical steps to reduce the impact of supply fluctuations:
- Order early — place your repeat prescription or online order at least 2 weeks before you need your next dose
- Use MedsLens to check stock availability across multiple UK pharmacies in real time
- Register with multiple pharmacies — different suppliers may have different stock levels
- Do not stockpile — hoarding contributes to artificial shortages and may result in expired medication
- Stay on your prescribed dose — do not skip doses or split pens to stretch supply
What If Your Dose Is Unavailable?
If your specific dose strength is out of stock, contact your prescriber before making any changes. Options may include:
- A temporary dose adjustment to an available strength
- Switching to a nearby pharmacy with stock
- A brief treatment pause with a plan to resume (your prescriber should advise on restarting)
Never attempt to combine lower-dose pens to achieve your prescribed dose without explicit medical guidance.
Looking Ahead
Eli Lilly has committed to increasing UK supply throughout 2025, with new manufacturing capacity expected to come online progressively. The company is working closely with the Department of Health and Social Care and UK wholesalers to improve distribution. While the situation is improving, patients should continue to plan ahead and use comparison tools to identify available stock.