Rising demand, rising risk with weight loss injections

21 Jul 2026 Estimated read time: 5 min read
Dr Sophie Haroon, Medicolegal Consultant at Medical Protection, shares how to navigate the medicolegal challenges of prescribing weight loss injections as they increase in popularity.

Obesity rates have more than doubled1 since 1990, with 64% of UK adults overweight or living with obesity in 20222. At the same time, eating disorders have increased globally3 with hospital admissions rising by 84% between 2015/16 to 2021/224. At least one person dies as a direct result of an eating disorder every 62 minutes5. 

Against this backdrop, new weight loss injections, specifically Mounjaro, Wegovy and Saxenda have emerged. Whilst weight loss medication isn’t new, there is now political enthusiasm to expand availability. However, people are already by-passing eligibility criteria. Their use, misuse and abuse by people with eating disorders has already been recognised and now presents complex challenges for GPs. 

Case study 

A 53-year-old lady, socially isolated, with an eating disorder and a BMI of 13 was found to be using Mounjaro. The provider contacted her GP to check for contraindications, after she had started the medication. The patient refused to allow the GP to share her medical history. The GP knew the patient was lying to get the medication and that the medication was harmful to her but had no clear way to intervene. Faced with issues of confidentiality, consent, mental capacity and mental health challenges, the GP sought advice from Medical Protection. 

The medicolegal issues

Doctors have a duty to maintain patient confidentiality. However, confidentiality is not absolute; disclosure is permitted in certain circumstances. One of these is when you have patient consent to disclosure.

In this case, the GP should seek patient consent to share relevant medical history with the provider. If the patient refuses, the GP may consider it appropriate to inform the provider that the patient has refused to give consent to disclose. It will be up to the provider to decide whether to continue prescribing, bearing in mind their regulatory responsibility to ensure the medication suits the patient’s needs.

Patients can still bypass systems, and some providers may not ask about contraindications. If a patient refuses consent but the GP believes it necessary to disclose that they have an eating disorder even without consent, the issue of mental capacity arises.

Adults are presumed to have mental capacity which is time and decision specific. Eating disorders can impact on capacity. The nature of eating disorder cognitions means patients may understand and communicate decisions but struggle to evaluate, i.e. weigh up risks due to their condition.

For example, a severely undernourished patient who insists on using weight loss injections is driven by the anxiety and fear of weight gain inherent to their diagnosis and lacks capacity to accept that the injections are contraindicated for them.

In this scenario, starting with the presumption of mental capacity, it is important to determine the patient’s mental capacity not only about weight gain but also regarding inappropriate use of weight loss injections. A second opinion from a fellow primary care colleague or psychiatrist is advisable due to the persuasiveness of some patients with eating disorders.

If it is determined that the patient lacks capacity and still refuses disclosure of their medical history, the GMC advises that doctors should try persuading them to share relevant information. If this fails, but the GP considers it would be beneficial to the patient and believes they lack capacity to make that decision, they may disclose relevant information to the appropriate person or authority. Here, the GP could justify informing the provider about the eating disorder based on the patient lacking capacity to make decisions around weighing up the dangers of using weight loss injections and the importance of the provider knowing their medical history.

In the situation where the patient has mental capacity and so has the right to make their own decisions about their treatment even if they appear wrong, this leaves the GP with a dilemma as the patient is ostensibly harming themselves.

The next step to consider is whether intervention under the Mental Health Act is appropriate. This may involve assessment and treatment of the eating disorder which would include stopping the use of weight loss injections. GPs could liaise with their local community mental health team, CRISIS mental health team, or even an approved mental health practitioner and psychiatrist if the patient is to be detained under the Mental Health Act (1983). 

Importantly, the patient needs to be kept informed of each decision. All steps and rationale must be clearly documented. While this article focuses on the medicolegal aspects, holistic care must also be considered.

Summary 

Weight loss injections may offer hope for obesity, but their use, misuse and abuse produce serious medicolegal challenges. GPs must manage a complex interplay of confidentiality, consent, mental capacity and mental health. Navigating each of these medicolegal and ethical paradigms is challenging and advice from your medical defence organisation should be sought. However, by following relevant legal and ethical guidance, doctors can help their patient from becoming another 62-minute statistic. 

Acknowledgment: The author would like to thank Dr Caroline Osborne-White, Medicolegal Consultant at Medical Protection, for her valuable contribution to this article.

 

References 

3 Wu J, Liu J, Li S, Ma H, Wang Y. Trends in the prevalence and disability-adjusted life years of eating disorders from 1990 to 2017: results from the Global Burden of Disease Study 2017. Epidemiol Psychiatr Sci. 2020 Dec 7;29:e191. doi: 10.1017/S2045796020001055. 

4 Eating disorders: How common is it?. NICE. July 2024. Available at: https://cks.nice.org.uk/topics/eating-disorders/background-information/prevalence/ 

5 Strategic Training Initiative for the Prevention of Eating Disorders (STRIPED) report. Harvard T.H. Chan School of Public Health. Available at: https://hsph.harvard.edu/research/eating-disorders-striped/research-reports/economic-costs-eating-disorders/

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