Which population groups have been studied in weight loss drugs trials? And how effective are the drugs in these groups: an agile scope of the literature

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Introduction

Obesity is becoming more common in Wales and effective ways to help people lose weight have been limited until now. New medicines being introduced in Wales, like semaglutide and tirzepatide, are GLP-1 drugs that have been shown to be effective in supporting some people to lose weight. To use them effectively, it’s important to know which groups of people have been studied in trials involving these drugs and who might benefit most. This work sits alongside another project we completed that investigated the effectiveness, safety and cost effectiveness of weight loss drugs as an adjunct to behavioural interventions.

The objective of this work was to identify which specific population groups (e.g., people with health conditions such as Alzheimer’s or heart disease) have been studied in weight loss drugs trials.

Main points

How up to date is this evidence?

We carried out the searches for this scoping review in 2025 and included relevant studies from a previous review we conducted. We included studies published between 2016 and 2025.

What we found

• There was limited evidence about the use of these drugs in specific groups of people. The studies we identified do not include the population groups that have been identified in Wales as potential priority groups for this drug.
• A small number of reviews studied people with conditions such as Alzheimer’s disease, heart disease, kidney problems, sleep apnoea, osteoarthritis, polycystic ovary syndrome, and prediabetes.
• Many trials excluded people with certain conditions, such as cancer, mental health problems, or serious kidney, liver, or heart disease.

What this means

• Even when evidence supports the use of weight loss drugs in a specific group of people, there may still be other medical or health reasons, that mean that the drugs are not safe to use for that patient or requiring special warnings or precautions.
• Since weight loss drugs are usually prescribed alongside diet and exercise, it’s important to check if patients can safely follow these lifestyle changes.

Technical information

We produced an agile scoping review which is designed to provide a broad overview of the evidence on a topic. We searched for studies looking at how well interventions using weight loss drugs alongside behavioural support work for weight management in adults who are overweight or living with obesity.

Glossary

GLP-1s: Glucagon-like peptide-1 receptor agonists (GLP-1s or GLP-1RAs) are medicines that help people feel fuller by mimicking a natural hormone released after eating. In the UK, there are several licensed GLP-1 medicines including semaglutide and tirzepatide.

Scoping review: A type of evidence review that maps what research exists on a particular topic or research area, rather than testing how well something works. It helps map the available evidence on a topic, clarify concepts as well as identify gaps in research