As demand for the weight-loss drug Mounjaro (tirzepatide) surges in the UK, experts are warning users not to attempt extracting an extra “fifth dose” from the KwikPen injector. The practice, widely discussed on social media, has been branded unsafe and potentially harmful by pharmacists and health officials.
What Happened
Users of Mounjaro, which is prescribed as four weekly doses via the KwikPen injector, have been trying to draw out leftover liquid from the device to create what they call the “golden dose.” This extra dose is not part of the prescribed treatment and has raised serious safety concerns.
The issue comes amid growing shortages of the drug in the UK, with prices set to increase from £122 to £330 per month starting September 1, 2025. The rising costs and limited availability have driven some patients to experiment with unsafe methods.
What Is the ‘Golden Dose’?
The “golden dose” refers to leftover medication in the KwikPen, originally intended for priming the device before each injection. Some users are attempting to withdraw this liquid with syringes or even makeshift tools, believing it can provide an additional full injection.
However, pharmacists and Eli Lilly, the drug’s manufacturer, stress that the KwikPen is only designed to deliver four accurate doses. Any attempt to take extra amounts is unsafe and not supported by medical guidance.
Background and Timeline
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Mounjaro KwikPen: Designed to deliver four weekly injections.
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Leftover Liquid: Exists for priming purposes only—not for additional doses.
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Social Media Influence: YouTube tutorials and online forums have promoted the “golden dose” hack, leading to increased risks.
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Upcoming Price Hike: Eli Lilly is set to raise prices on September 1, sparking stockpiling and growing demand.
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Shortages: Pharmacies including Superdrug and Asda have already reported running out of stock.
Public and Social Media Reaction
On platforms such as Facebook and YouTube, some users have been sharing tips on how to extract the “golden dose,” while others have expressed concern about safety. Listings for “golden dose plungers” have even appeared on eBay UK, further fueling the trend.
One user wrote online: “Might need to take the golden dose, just due to waiting for my next delivery.”
Expert and Official Warnings
Olivier Picard, chairman of the National Pharmacy Association, strongly condemned the practice, calling it “completely inappropriate” and warning of risks including contamination from plastic or glass, inaccurate dosing, and unsafe side effects.
Pharmacies such as Asda and The Family Chemist have also urged customers to stick to their prescriptions. Reported side effects of overdosing include nausea, constipation, and diarrhoea.
Eli Lilly confirmed that while small amounts of medication remain in the pen after use, “an additional complete dose cannot be dialled” and the pen should always be discarded after four doses or within 30 days of opening.
What Happens Next
With shortages continuing and a significant price hike imminent, demand for Mounjaro is expected to remain high. Health officials and pharmacies are urging patients not to risk their safety with unapproved hacks and instead seek professional medical guidance.
This story may be updated with more information as it becomes available.
