Weight loss drugs: The impact of NICE and the FDA


Sarah Gibbs and Emma Lyons

Weight loss drugs: The impact of NICE and the FDA

Alex Verrone / Shutterstock.com

With weight-loss drugs on the rise, regulatory approval is shaping the lucrative market in the UK and US, explain Sarah Gibbs and Emma Lyons of Appleyard Lees.

In March 2023, the National Institute for Health and Care Excellence (NICE) published guidelines recommending the use of semaglutide for weight management. Semigltuide was officially launched for use in the whole of the UK in September 2023.  

Rates of obesity (defined as having a body mass index of 30kg/m2 or greater) have been rising worldwide, with the number of people living with the condition having tripled since 1970.

In the UK, government initiatives aimed at tackling obesity—such as a traffic light scheme on food labels, a sugar tax on soft drinks, and the inclusion of calorie information on restaurant menus—have proved largely ineffective.  

Typically, recommendations for treating obesity include lifestyle modifications, such as calorie restriction, and increased physical activity. However, although these changes may be successful in the short term, few individuals maintain long-term weight loss, and weight regain is common. This may be due to compensatory increases in appetite as an evolutionary mechanism to regain weight that has been lost, for example.  


Semaglutide was developed by Novo Nordisk (Novo). It aids in promoting weight loss and preventing weight regain by mimicking the action of glucagon-like peptide-1 (GLP-1). GLP-1 is a hormone that is secreted into the bloodstream from the lower gastrointestinal tract in response to greater nutrient availability following food consumption. One of the target sites of GLP-1 is the brain, where it acts to suppress appetite and promote satiety (or a feeling of “fullness”).  

A 68-week randomised, double-blind, placebo-controlled trial investigating the efficacy and safety of semaglutide, alongside lifestyle interventions, found that participants in the group receiving the drug lost an average of 14.9% of their body weight compared to only 2.4% in the placebo group.

Participants receiving semaglutide also showed improvements in cardiometabolic risk factors and patient-reported quality of life. However, the drug was found to cause side effects, primarily affecting the gastrointestinal system, such as nausea, diarrhoea and vomiting.

Novo owns several patent families related to semaglutide. For example, they have patents to the active ingredient itself as well as to compositions comprising semaglutide for use in the prevention or treatment of obesity (see EP 1,863,839 B1 and EP 2,866,825 B1, respectively). Novo has a monopoly over the drug until 2031.  

Semaglutide is currently marketed, and licenced, for use in weight loss under the tradename Wegovy. However, it is also available in the UK under the trade names Ozempic and Rybelsus as a treatment for type II diabetes.  

Supply and demand 

Wegovy is also available for use in weight management in the US, with the Food and Drug Administration (FDA) approving its use in June 2021. Following approval by the FDA, both Wegovy and Ozempic soared in popularity and became dubbed as miracle weight loss drugs amongst celebrities and on social media platforms.

The resulting high demand caused shortages, with doctors given stricter guidelines on prescribing these medications to preserve the limited supply. Novo warned of the risks of these shortages as counterfeit Ozempic began to appear on shelves in US pharmacies.  

Shortages of Ozempic have also been seen in the UK. This has largely been driven by off-label prescribing of the drug for weight loss, as people have sought to use the drug as an alternative to Wegovy (where demand has outstripped supply).

It is predicted that because of the increased demand, shortages of both Ozempic and Wegovy in the UK may last until late 2024. Of course, this has an impact on those living with type II diabetes as well as those looking to lose weight.  

What may the future hold? 

The approval of semaglutide for weight management in both the US and the UK, and the resulting high demand, will likely lead to an expansion in the weight-loss drugs market. One product already on the horizon is tirzepatide (marketed as Mounjaro).

Tirzepatide, developed and patented by Eli Lilly, mimics the action of both GLP-1 and glucose-dependent insulinotropic polypeptide (GIP), another appetite-suppressing hormone. Tirzepatide is predicted to lead to greater weight loss due to the additive effect of targeting different satiety pathways and has already shown promising results in a phase III clinical trial.  

Given the high demand, it is also likely that generic versions of Wegovy will begin to appear following the expiry of Novo’s monopoly. In fact, generic drug companies are already trying to expand into the lucrative weight loss market, which is predicted to be worth more than USD 100 billion by the end of the decade.  

For example, Mylan Pharmaceuticals (Mylan) is challenging the validity of a number of Novo’s patents in the US. The US Patent and Trademark Office (USPTO) has recently agreed to review the validity of a Novo patent covering dosage regimes for semaglutide, on the basis that Mylan had shown a reasonable likelihood that the patent was invalid.

However, this comes off the back of the USPTO’s refusal to review the validity of two other Novo patents covering the active ingredient itself. This decision clearly represents a setback to Mylan’s efforts to clear a legal path for generic versions of Ozempic and Wegovy in the US.  

It will be interesting to see how the market develops.  

Sarah Gibbs is a senior associate and patent attorney at Appleyard Lees. She can be contacted at: Sarah.Gibbs@appleyardlees.com

Emma Lyons is a trainee patent attorney at Appleyard Lees. She can be contacted at: emma.lyons@appleyardlees.com

National Institute for Health and Care Excellence, Food and Drug Administration, obesity, sugar tax, regulation, food labels