Weighty matters: GLP-1s and the UK regulatory diet they cannot escape

GLP-1 is a natural gut hormone released after eating that stimulates insulin secretion, suppresses appetite and slows down digestion. GLP-1 receptor agonists are medications that mimic this hormone to improve blood sugar control in type 2 diabetes and promote weight loss in obesity.

In recent years, the UK has experienced a significant spike in the use of GLP-1 weight loss medications, including semaglutide and tirzepatide. Reports suggest that nearly one in ten adults in Britain have either recently used a weight-loss drug or would like to use one.

This growing demand has led to a shift in consumer behaviour, itself causing rapid innovation in the marketplace. Businesses increasingly advertise food products as suitable for individuals taking GLP-1 medicines. Business models have also started to emerge that integrate prescription services, online consultations and lifestyle support programmes within subscription-based frameworks, while social media campaigns and consumer marketing have intensified as companies seek to seize this market opportunity.

However, this commercial growth is accompanied by strict regulatory oversight. Last year, the UK Advertising Standards Authority (ASA), the Medicines and Healthcare products Regulatory Agency (MHRA), and the General Pharmaceutical Council (GPhC)  jointly issued an updated Enforcement Notice, which outlines compliance guidance for businesses operating in this sector. In carrying out its statutory functions, the MHRA has powers to monitor and investigate complaints relating to medicines advertising and both the MHRA and ASA have continued to take enforcement action.

Companies developing products, services or marketing strategies related to GLP-1 medications should study the guidance as outlined in the Enforcement Notice and the wider regulatory framework to mitigate the risk of regulatory action.

Advertising

In the UK, under the Human Medicines Regulations 2012 (HMRs) and the UK Committee of Advertising Practice (CAP) Code, it is unlawful to advertise prescription-only medicines (POMs) or encourage people to take prescription medicines. This creates substantial challenges for businesses seeking to promote and advertise services or products connected to GLP-1s.

The regulatory climate around GLP-1 advertising has increased considerably in recent months.

In the current environment, ads including "GLP-1" or other relevant terminology, such as "weight-loss injection, may attract both the MHRA's and ASA's scrutiny. In January 2026 alone, the MHRA took action against five companies and, in February to date, there have already been five weight-loss medication rulings upheld by ASA.

Notably, the ASA is actively deploying AI-powered monitoring tools, which use machine learning to scan online advertising across websites and social media platforms for non-compliant content by identifying relevant keywords and themes. This significantly increases the risk for businesses, as non-compliant advertising is increasingly likely to be detected and acted upon.

Businesses should ensure that any marketing materials make clear that they are not supplying, endorsing, or encouraging the use of GLP-1 medications, and not "influencing" new users to start the medication. Although the advertising regulatory regime in this area remains very strict, it will be interesting to see whether regulators adjust their approach as this consumer trend grows. For the time being, businesses should proceed on the basis of the current law and published regulatory guidance.

Food claims

Food retailers have started to launch new product ranges aimed at consumers using GLP-1 medications. In the UK, various supermarkets have introduced ranges marketed as suitable for those on weight-loss medications, including products with smaller portion sizes and claims relating to this.

Businesses developing GLP-1-focused ranges should be careful to avoid misleading consumers or making unauthorised nutrition or health claims. The regulatory framework governing nutrition and health claims on foods still applies to these products, and businesses will need to ensure claims being made can be supported by appropriate substantiation to avoid being considered misleading by regulators.

Product and healthcare considerations

Under the HMR, only medicines that have a valid UK marketing authorisation from the MHRA can be sold in the UK. The MHRA has issued warnings about black market GLP-1 products, and businesses must ensure that any GLP-1 medications offered are appropriately licensed.

POMs can also only be sold or supplied by a registered UK pharmacy with a valid prescription from an appropriate prescriber, such as a doctor or pharmacist. NHS access to POMs is limited by stringent eligibility criteria. Consequently, weight-loss POMs will, in most cases, probably need to be obtained through private healthcare providers.

For businesses using models that provide online consultations and prescribing services, strict regulatory requirements also apply, including ensuring meeting standards set by the GPhC and the General Medical Council.  This includes ensuring that medicines used for weight management are not prescribed on the basis of a questionnaire alone, and that extra safeguards are in place to ensure the medicines are clinically appropriate for patients.

In addition, any business providing regulated healthcare activities in line with GLP-1 prescriptions must be appropriately registered with the Care Quality Commission, and with the relevant body in the devolved nations where required.

Businesses considering new business models will need to ensure that the business providing the POMs is registered as a pharmacy with the GPhC, registered prescribers are used to prescribe MHRA authorised weight loss medications, and that appropriate regulatory standards are met.

GLP-1s in the EU

In the EU, rules on medicines, including access to GLP-1s and other advanced therapies, are governed mainly by the EU Medicines Directive (2001/83/EC) and the centralised EU marketing authorisation framework, which requires a formal authorisation before a product can be placed on the market.

However, EU law does not create a right to direct-to-consumer access and consequently decisions on prescribing, pricing and reimbursement sit largely with individual Member States, whose health systems can severely limit off-label or non-medical use.

While the EU framework sets common standards for quality, safety and efficacy, national authorities of each individual Member State decide how and when these products are used and funded in practice, often via stringent clinical eligibility rules. Therefore, it is important for businesses supplying or advertising GLP-1 medications to be mindful that different rules may exist across Member States in the EU.

Osborne Clarke comment

The regulatory frameworks surrounding GLP-1s and weight loss are strict, and regulators are hot on taking enforcement action in this area. However, this remains a rapidly growing market with opportunities for businesses that are willing to navigate the regulatory landscape carefully.

Businesses operating in this space need to be aware of the regulations and guidance on advertising, food labelling and healthcare services in the UK and the EU. With appropriate compliance measures in place, they can still take advantage of this growing market while managing regulatory risk effectively.

Kiki Jackson, solicitor apprentice, and Shereen Younis, trainee solicitor, assisted in writing this Insight.