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Nearly half of people (47%) taking weight-loss medication said they modified their dosing regimen as a way to save money, a survey conducted by LloydsPharmacy Online Doctor has revealed.
Results of the survey, published on 28 January 2026, found that nearly one-quarter (24%) of respondents said that they had taken smaller doses than prescribed, as a way to make the prescription last longer, while a similar proportion (23%) said that they had combined residual product from pens to create an additional extra dose.
LloydsPharmacy Online Doctor surveyed 2,000 people between 15 and 20 January 2026. Of these, 501 said they had used glucagon-like peptide-1 (GLP-1) receptor agonists, such as Wegovy (semaglutide; Novo Nordisk), Mounjaro (tirzepatide; Eli Lilly) and Ozempic (semaglutide; Novo Nordisk), and 285 said they currently were.
More than one-quarter of respondents (28%) reported that they had knowingly bought weight-loss injections from unlicensed sellers, including the dark web or social media.
A further 12% of respondents said that while they could not be sure, they suspect their weight-loss injections could have come from an unregulated provider.
Kieran Seyan, chief medical officer at LloydsPharmacy Online Doctor, said: “GLP-1 medications have transformed the treatment of obesity. They are helping patients achieve meaningful, sustained weight loss and improving health outcomes for those who are clinically eligible.
“However, these medicines are still relatively new, and the evidence base relates to specific doses and treatment pathways. Experimenting with dosing ‘hacks’ to make prescriptions last longer is a risky strategy and can expose patients to safety risks and unknown side effects.”
A separate survey of 5,260 adults in the UK, carried out by phone between January and March 2025 and published in BMC Medicine on 8 January 2026, found that 2.9% (2.4–3.4%) of respondents said they had used a GLP-1 or GLP-1/ glucose-dependent insulinotropic polypeptide (GIP) medication to support weight loss in the past year, which if extrapolated to the UK population, would amount to approximately 1.6 million adults.
In the same survey, 1.7% (1.4–2.1%) of respondents said they had used GLP-1 or GLP-1/GIP medication exclusively for weight loss, which would extrapolate to 910,000 adults.
The price of Mounjaro rose significantly in September 2025, with prices going up to £133 for the 2.5mg dose and £330 for 12.5mg and 15.0mg doses.
In an alert issued on 30 December 2025, the Medicines and Healthcare products Regulatory Agency (MHRA) warned patients to steer clear of weight-loss products promoted on social media and buy medicines only from registered UK pharmacies or legitimate retailers.
More than 5,000 illegally traded GLP-1 products were seized by the MHRA’s Criminal Enforcement Unit in 2025.
