Weight-loss medications, including Mounjaro and Wegovy, are gaining increasing attention as effective treatments for obesity, offering new hope for millions struggling with weight management. These drugs, currently available through the NHS in certain areas, are set to be rolled out more widely in the coming years, although experts caution that demand may outpace the system’s ability to manage access and support.
How Do Wegovy and Mounjaro Work?
Both Wegovy (semaglutide) and Mounjaro (tirzepatide) function primarily as appetite suppressants, mimicking natural hormones that regulate hunger and satiety. Semaglutide, also used in diabetes management under the brand name Ozempic, and tirzepatide, a newer treatment, help to curb appetite and promote a feeling of fullness. Both drugs are administered via weekly injections, which patients can administer themselves at home using pre-filled pens, targeting areas like the upper arm, thigh, or stomach.
Wegovy works by mimicking glucagon-like peptide-1 (GLP-1), a hormone that signals the brain to reduce hunger after eating. Mounjaro, in addition to mimicking GLP-1, also targets glucose-dependent insulinotropic polypeptide (GIP), a hormone involved in metabolism and energy regulation, making it a more comprehensive solution for weight management.
Weight Loss Results and Expectations
Clinical trials have shown promising results for both drugs, with users of Wegovy typically losing more than 10% of their body weight after a year of treatment, particularly when combined with diet, exercise, and behavioral modifications. Mounjaro has also shown strong results, with some trials suggesting even higher weight loss figures. However, experts warn that once treatment stops, patients are at risk of regaining lost weight, a common challenge with weight-loss medications.
Access to Weight-Loss Drugs on the NHS
As of now, Wegovy is available on the NHS in England, Wales, and Scotland, but access is restricted. To qualify for a prescription, patients must be obese and have at least one weight-related health condition, such as high blood pressure or cardiovascular disease. The NHS has set guidelines that limit treatment to a maximum of two years, and patients must also engage in a diet and exercise program as part of their treatment plan.
The National Institute for Health and Care Excellence (NICE) has recommended Mounjaro be made available to NHS patients from March 2025, initially for those with obesity-related health conditions. However, the full rollout of Mounjaro will take time, with expectations that the NHS could take over a decade to provide widespread access. NICE estimates that around 3.4 million people could eventually qualify for the treatment, but only 300,000 may be eligible in the first three years.
The Private Market: Costs and Availability
For those who wish to access these drugs outside of the NHS, Wegovy and Mounjaro are available privately at a cost of £200 to £300 per injection. While these medications can be purchased at various pharmacies, clinics, and even supermarkets, experts warn against purchasing from unregulated sources, as there is a growing black market for these drugs, including online sales without prescriptions. In some cases, the drugs have been sold illegally in beauty salons.
Side Effects and Risks
Like all medications, weight-loss injections come with potential side effects. The most common include nausea, vomiting, bloating, constipation, and diarrhea. Some users also report hair loss. While these side effects are usually temporary, some individuals may find them intolerable, leading them to discontinue the drugs. More serious, though rare, side effects include gallbladder problems, kidney issues, and depression.
Experts caution that the risks are heightened when the drugs are abused, particularly when taken without medical supervision or purchased from non-regulated sources. There have been reports of severe complications, such as pancreatitis, among individuals misusing these medications.
Long-Term Effects and Dependency Concerns
Research suggests that many people will regain most of the weight lost after stopping these treatments, as their appetite and food cravings return to pre-treatment levels. Experts stress the importance of using these medications in conjunction with lifestyle changes, including improved diet and increased physical activity.
Health Secretary Wes Streeting has raised concerns about the potential for people to develop a dependency on these drugs, viewing them as a quick fix rather than a long-term solution. This concern is compounded by the occasional shortages of Wegovy, though the manufacturer, Novo Nordisk, has assured that the NHS has a protected supply.
What is Obesity and Who Qualifies for Treatment?
Obesity is defined as having excess body fat, and in the UK, approximately one in four adults is considered obese. The standard measure of obesity is Body Mass Index (BMI), which calculates a person’s weight relative to their height. A BMI of 30 or above is classified as obese, while a BMI over 40 is considered severely obese. For some ethnic groups, such as those of Asian, African, and Middle Eastern descent, lower BMI thresholds are used to assess obesity.
While BMI is a useful tool, it has limitations, particularly for individuals with high muscle mass who may have a high BMI but low body fat. Despite this, BMI remains a valuable screening tool for assessing overall weight status.
Conclusion: A Step Forward in Obesity Management
While Mounjaro and Wegovy represent significant advancements in the fight against obesity, experts warn that they should not be seen as a panacea. Weight-loss medications must be integrated into a broader strategy that includes lifestyle changes, such as healthier eating and regular exercise. With growing demand and an overstretched NHS, careful planning will be crucial in ensuring these treatments are both accessible and sustainable in the long term.
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