By Emily May, Research Manager, and Ditto Antony, Research Analyst, Deloitte

Our recent report, ‘Be brave, be bold’, the 15^th in our Measuring the return from pharmaceutical innovation series, found that GLP-1 (glucagon-like peptide-1) agonist drugs (GLP-1s) are driving unprecedented growth in R&D returns, offering new hope for patients struggling with obesity, diabetes and a growing number of other diseases. Our comprehensive research, which focuses on the late-stage research and development (R&D) pipelines of the 20 top biopharma companies by research spend, shows that GLP-1s are targeting a range of conditions that are currently rife with high levels of unmet medical need. However, the growing prevalence of these diseases also presents significant challenges, particularly around access and affordability. In this blog, we explore the rapid growth of GLP-1s in the late-stage R&D pipelines, their growth across multiple therapy areas of high unmet medical need, and insights from UK prescribers to assess access and affordability issues.

What are GLP-1s?

GLP-1s are a class of medications initially approved to treat type 2 diabetes. They mimic the action of the naturally occurring hormone GLP-1, which is released from the gut after eating and plays a key role in regulating blood sugar and appetite. GLP-1 agonists work by increasing insulin production in the pancreas (which helps to control the amount of blood sugar); reducing glucagon secretion (which helps lower blood sugar); and slowing digestion which helps people feel full for longer, thereby reducing their appetite.¹

Clinical evidence shows that these actions collectively improve blood sugar control and contribute to weight loss in individuals with type 2 diabetes. More recently, GLP-1s have emerged as game-changers in the treatment and management of obesity. They are also showing early potential as a treatment for Alzheimer's due to their anti-inflammatory properties and in treating addiction, mental health and sleep apnoea as well as neurological, psychiatric, cardiovascular and kidney diseases.²

How are GLP-1s impacting the return on investment in R&D?

Our Measuring the return from pharmaceutical innovation report series analyses the internal rate of return (IRR) that our cohort of the top 20 biopharma companies can expect to earn from their late-stage pipelines. In our latest analysis, the cohort’s forecast IRR reached 5.9 per cent, a 1.6 percentage point increase compared to 2023. This positive shift is attributed to the introduction of high-value products, notably GLP-1s. If GLP-1s are excluded from the analysis, the IRR for 2024 falls to 3.7 per cent and to 3.4 per cent for 2023, highlighting the substantial impact of GLP-1s on overall industry IRR, see Figure 1.

Figure 1. Internal rate of return, with and without late-stage GLP-1 assets

Source: Deloitte analysis, 2025.

GLP-1s have played a major role in driving the uptick in forecast peak sales. The cohort’s average forecast peak sales per asset increased to $510 million in 2024.   When GLP-1s are excluded from our analysis, the cohort’s average peak sales drops to $370 million.

Blockbusters are drugs with a forecast peak sale of greater than $1bn. In our 2024 analysis, there are ten blockbuster GLP-1s in the late-stage pipeline of our cohort, six of which have forecast peak sales greater than $10bn. One oral GLP-1 obesity asset saw a particularly large increase due to improved production efficiency, resulting in better accessibility through pricing, distribution, and ease of administration. While late-stage GLP-1s with the highest forecasts do sit in the obesity and diabetes therapy areas, they are also distributed across other therapy areas which also have high unmet medical needs. This includes potential treatments for Alzheimer’s disease, obstructive sleep apnoea (OSA), osteoarthritis and cardiovascular indications including chronic heart failure (CHF), peripheral vascular disease (PVD) and hepatic & biliary conditions such as non-alcoholic steatohepatitis (NASH).

The success of GLP-1s offers several key takeaways for enhancing R&D productivity. First, it underscores the importance of focusing on areas with high unmet medical need, such as obesity and diabetes. This approach can lead to both higher returns and improved global health outcomes. Additionally, the success of GLP-1s in the obesity market demonstrates the potential of focusing on less crowded therapeutic areas. Figure 2 highlights the remarkable increase of forecast revenue proportion derived from obesity assets over the last three analysis cycles, increasing from 1 per cent in 2024 to the second highest contributor with 16 per cent of forecast revenue.

Figure 2. Forecast revenue for the top 20 cohort by therapy area

Source: Deloitte analysis, 2025.

UK-based GLP-1 prescribers identified access, safety and affordability as the top challenges

Given the significant impact and growing prominence of GLP-1s, we sought to understand the perspectives of UK stakeholders regarding their use, by surveying 138 GLP-1 prescribers to understand their experiences, hopes and concerns. The survey revealed both considerable enthusiasm and significant practical challenges, especially around access, safety and affordability. For example:

• when asked about the top two biggest unmet needs or challenges related to prescribing GLP-1 receptor agonists for weight loss, patient access and long-term safety data emerged as the joint primary concerns, cited by 49 per cent and affordability was cited as the third biggest concern (38 per cent)
• other perceived challenges were lack of awareness amongst healthcare professionals (25 per cent), and lack of awareness among patients (14 per cent), as well as the need for more convenient formulations (14 per cent).

Prioritising safety in prescribing decisions

The concern regarding long-term safety data is reflected in our survey of prescribers.  When asked about the primary factors they considered when choosing a specific GLP-1 agonist for a weight loss patient, the risk profile and safety data was the most selected consideration, chosen by 32 per cent of respondents. Eligibility for use in weight loss was the second most important factor (26 per cent). Considerations around efficacy, such as weight loss potential (18 per cent) and efficacy in HbA1c reduction (18 per cent), were identified as important, but ranked below safety and eligibility. Indicating that once a decision to potentially prescribe has been made, broader access issues assume greater importance.

Despite the identified challenges, there is a strong consensus regarding the future trajectory of GLP-1s in obesity management. An overwhelming majority of respondents anticipate growth in the use of GLP-1s over the next five years, with 74 per cent expecting a significant increase in use and 19 per cent predicting a moderate increase (see Figure 3).

Figure 3. Physician outlook on GLP-1 growth in obesity and potential for new indications

Source: Deloitte analysis, 2025.

This optimism extends beyond their current core indications. When questioned about the potential of GLP-1s for treating other conditions, such as cardiovascular or neurological diseases, sentiment was highly positive. Half (50 per cent) of the respondents are somewhat optimistic, and nearly a third (32 per cent) are very optimistic, indicating strong belief in the broader therapeutic potential of this novel mechanism of action.

The impact on healthcare expenditure

While the potential benefits and expanding use of GLP-1s are clear, our survey of UK prescribers highlights significant concerns about the financial impact on the healthcare system. Respondents were asked how they anticipate the cost of GLP-1s to impact overall healthcare system expenditure in the next five years. A substantial majority (78 per cent) expect GLP-1 expenditures to place a growing burden on the healthcare system (41 per cent predict a moderate increase, and 37 per cent anticipate a significant increase). Only 10 per cent expect costs to remain stable.

Conclusion

GLP-1s demonstrate remarkable potential in addressing obesity and diabetes management, alongside emerging evidence of their benefits in other therapy areas. While there is increasing optimism regarding the future applications of GLP-1s in these other therapeutic areas, as demonstrated by the depth and breadth of GLP-1s in the late-stage R&D pipelines, the projected high increase in healthcare expenditure that could result will require careful consideration of cost-effectiveness and the development of sustainable access strategies.

Patient access, long-term safety data, and affordability are paramount concerns by prescribers, and which will need to be addressed if these promising treatments are to reach those with high unmet needs.  Balancing the clinical promise of GLP-1s with responsible resource allocation is crucial for optimising their positive impact on global health as is the need to improve prescribers and users understanding of this novel therapy area.

Emily May, Research Manager, Centre for Health Solutions

Emily is a manager in the Centre for Health Solutions where she applies her background in both scientific research and pharmaceutical analytics to produce supported insights for the Life Sciences and Healthcare practice. Emily leads the research and publication of the life sciences insights, performing thorough analysis to find solutions for the challenges impacting the industry and generating predictions for the future. Prior to joining the centre, Emily worked as an Analytical Scientist conducting physical chemistry analysis on early stage drug compounds and previously lived in Antwerp, Belgium where she researched and developed water-based adhesive films.

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Ditto Antony, Research Analyst, Centre for Health Solutions

Ditto is a Research Analyst within the Insight team based in Hyderabad, India. He supports Deloitte’s UK Centre for Health Solutions by analyzing the Life Sciences and Healthcare industry and providing insights into the trends. He has a background in Commerce and Management. His expertise includes market research, data interpretation, and delivering actionable intelligence to stakeholders.

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¹ A Complete List of GLP-1 Agonists: How They Work and Why They're Essential for Diabetes and Weight Loss - Bmi Doctors

² Ibid.