Weight Loss Injection Pen & Tape Measure

Recently, YKC’s Dave Duffy looked at the less-explored potential benefits of weight loss drugs for patients, the NHS and society in general. But things move fast. So in this post, he revisits the topic and examines the current state of play.

We live in strange times. Recently, for example, I was speaking with a colleague whose patient had told him that the increased cost of their weight loss medication meant they’d had to give up their gym membership. The paradox almost makes your head explode.

Weight loss – a growth market

Since I last wrote about weight loss drugs and knee replacement, less than a year ago, the landscape has changed significantly. According to the BBC, “an estimated 1.5 million people in the UK use these drugs … Prices vary but it generally costs between £100 and £350 a month, depending on the dose and lifestyle support.”

Prices rose most steeply in August 2025, most notably for Mounjaro, manufactured by Eli Lilly. The rise was attributed to simple supply and demand economics and the less simple, President Tump-driven equalisation of prices in the US and everywhere else.

More than 90% of users are believed to be paying privately for their medication, a reflection of the urgent demand for the products and the fact that weight loss medication is only available on the NHS for patients who meet four of the following five criteria:

Type 2 diabetes
High blood pressure (hypertension)
Heart and blood vessel disease (cardiovascular disease)
Obstructive sleep apnoea
Abnormal blood fats (dyslipidaemia)

Reasons for concern?

The rapid growth of the market has caused some concerns. There are worries that the price rise combined with limited supply from the NHS is feeding (no pun intended) a two tier-system in the UK.

There’s a growing impact on the surgical pathway. One example of this is the way we deliver anaesthetic. Historically, if somebody were due for a general anaesthetic, you’d work on the assumption that after four hours without food or drink there would be nothing in the stomach. Weight loss drugs slow down the process of gastric emptying, so anaesthetists are now having to ask patients whether they are on weight-loss medication and, if so, adjust the time allowed for gastric emptying accordingly. That inevitably has an impact on the planning and delivery of treatment.

The impact of faster weight regain

Then there’s the matter of the study recently released by the University of Oxford, which found that stopping weight-loss drugs is linked to faster weight regain than ending diet programmes. Researchers stressed this isn’t a failing of the treatment, more a reflection of the nature of “obesity as a chronic, relapsing condition.”

The practical effect of that, though, seems to be a need to either remain on weight loss drugs for life (or, at least, to periodically return to them), or see your weight return to its original state within two years.

Clearly, either option has a range of consequences, one of which is the as-yet unknown impact of rapid weight gain on any knee implant. Studies have been carried out into patient weight post-knee replacement, but not – as far as I am aware – in this context. And if millions of people are going to be coming on and off weight loss drugs over the next few years, that context matters.

An overall positive

Despite the above issues, the overall positives appear to outweigh the negatives. That’s why the WHO has conditionally recommended weight loss injections for treating obesity.

As I explored in my last post on this matter, obesity increases surgical risk, so anything to reduce that risk is welcome. Reducing weight helps to reduce the load on arthritic joints, which may help to delay the need for knee surgery in the first place – also welcome.

More broadly, and without ignoring the needs of those who would like to access weight loss drugs but can’t afford it, there does appear to be a broader benefit to the NHS and society as a whole from the current state of play.

From diabetes control to heart health and elective surgery, our health system as a whole is benefiting from a healthier, less obese population – yet has had to fund only a fraction of it. It’s hard to imagine that health economists aren’t looking at this model and thinking, how do we replicate it in other areas?

If you are suffering from osteoarthritis, whether you’ve already been using weight loss medication or not, contact us, or call us on 03453 052 579.

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