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GLP-1: The Science Behind Revolutionary Breakthroughs in Metabolic Health

Dr. Arisha Sharif

June 02, 2025

GLP-1 agonist medications such as Ozempic and Wegovy have become increasingly popular over the last few years, due to their increased availability to the public, celebrity endorsements and their evidence base for weight loss. Aside from weight loss, GLP-1 agonist medications have also been shown to combat cardiovascular, metabolic and neurodegenerative conditions.

Metabolic health affects many different processes in the body and is fundamental to general wellbeing. GLP-1 is a naturally occurring hormone produced by the body that works in the insulin secretion pathway and is a key component in metabolic regulation. To understand how medications such as Ozempic and Wegovy work, we must first understand what GLP-1 is and how it works in the body.

What is GLP-1?

Glucagon-like peptide-1, or GLP-1, is a naturally occurring hormone that is made by cells in the intestine and released when food is consumed. GLP-1 has a number of different functions that work towards its main goal: lowering blood sugar levels, which increase when food is consumed.

Firstly, GLP-1 stimulates the pancreas to secrete insulin. Insulin works by promoting glucose uptake into cells and out of the bloodstream, thus lowering blood sugar levels. GLP-1 also supresses glucagon secretion. Glucagon increases blood sugar levels by releasing glucose from the liver into the bloodstream, so stopping glucagon secretion lowers blood sugar levels. GLP-1 also influences delaying gastric emptying, meaning it slows down food from leaving the stomach, which causes a slower rise in blood sugar and helps you feeling full for longer.

GLP-1 also works on the brain, as it has receptors in the hypothalamus, causing a psychological effect of reducing the feelings of hunger and making you feel fuller for longer.

Despite its benefits, naturally occurring GLP-1 is broken down very quickly in the body by an enzyme named DPP-4, so its effects on the body are short-lived.

Due to GLP-1’s powerful effects on the gut and brain in lowering blood sugar, reducing hunger cues and making you feel fuller for longer, medications that mimic GLP-1, called GLP-1 agonists, can lead to substantial weight loss and good glycaemic control.

What is metabolic health?

Metabolic health refers to how well our body can manage energy and maintain homeostasis. Poor metabolic health can sometimes lead to Metabolic Syndrome, which is a combination of abnormalities occurring in the body, such as insulin resistance, impaired glucose tolerance, and raised cholesterol levels.

Below are some indicators of good metabolic health:

1. Normal Blood Sugar Levels: Having blood sugar levels in a normal, healthy range help prevent against metabolic syndrome and other conditions such as diabetes.

2. Healthy Blood Pressure: Blood pressure readings in the normal, healthy range decrease the risk of cardiovascular conditions such as heart attacks and strokes.

3. Healthy Cholesterol Levels: Lowering your LDL-cholesterol levels and overall cholesterol reduces the risk of cardiovascular conditions.

4. Healthy Waist Circumference: Maintaining a healthy weight and waist circumference reduces the risk of metabolic syndrome.

What is the role of GLP-1 in metabolism?

GLP-1 works in several ways in the process of metabolism, which begins when food is consumed, and blood sugar levels begin to rise. By stimulating insulin secretion and reducing glucagon release, GLP-1 reduces blood sugar levels. As it also works on slowing food emptying from the stomach, it promotes fullness with a dual effect on the brain by controlling hunger cues.

What is the role of GLP-1 in managing diseases?

Diabetes

GLP-1 agonist medications have been used in the management of Type 2 Diabetes for many years. Type 2 Diabetes is a condition where the body has some degree of insulin resistance, meaning it no longer responds effectively to the insulin made by the body in response to blood sugar levels. As we have discussed, GLP-1 stimulates insulin secretion and reduces glucagon release, working towards maintaining normal blood sugar levels. Type 2 Diabetes is also closely linked with weight, and as GLP-1 agonists can help with weight loss, this has been an effective treatment for people with Type 2 Diabetes to both regulate blood sugar levels and lose excess weight. The SUSTAIN clinical trial demonstrated that the GLP-1 agonist Semiglutide had consistently better and sustained glycaemic control and weight loss compared to other comparators.

Obesity

Obesity is now widely recognised as being a medical condition, affecting 1 in 4 adults in the UK. Obesity is defined as carrying excess body weight and can increase risks of other diseases such as cardiovascular diseases, Type 2 Diabetes, sleep apnoea and more, by substantial amounts. Clinical evidence, such as the STEP trial, showed that when used in combination with a calorie controlled diet and intensive behavioural therapy, participants lost a significant amount of weight compared to the placebo group. Medications such as Ozempic and Wegovy are now being used for treatment of obesity in the UK and other parts of the world, under specialist weight loss management teams.

Non-Alcoholic Fatty Liver Disease

Non-Alcoholic Fatty Liver Disease, also known as NAFLD, is a condition where excess fat around the liver leads to inflammation and liver damage, causing the liver to not be able to function properly. NAFLD is more likely to occur in people who have obesity or Type 2 Diabetes. As we have discussed, GLP-1 agonist medications have been proven to be effective in managing obesity and Type 2 Diabetes, so it may also play a part in managing NAFLD too. This study found that GLP-1 agonists have been shown to be effective in lowering body weight and lowering liver fat content, suggesting that it could be effective in treating NAFLD.

Cardiovascular Disease

Cardiovascular disease is a major leading cause of mortality around the world. The risk of this goes up with conditions such as obesity and metabolic syndrome, and there has been many studies to find effective treatment options that lower cardiovascular risk. As we know, GLP-1 agonists aid weight loss and promote metabolic health, reducing risk from that aspect, however evidence suggests that GLP-1 agonist medications work on reducing blood pressure and blood lipids too. This study found that numerous trials showed positive cardiovascular benefits with GLP-1 agonist medications.

Cognitive health

Cognitive conditions such as Dementia and Parkinsons Disease effect a massive number of people all over the world. Although GLP-1 agonist medications have traditionally been used to treat Type 2 Diabetes and obesity, there is emerging evidence that it may also affect cognitive health. Some studies suggest that GLP-1 agonist medications may have a protective cognitive effect, by delaying progression to dementia, however more research and evidence is needed to make a strong correlation.

Lifestyle modifications when using GLP-1 agonist medications

Although GLP-1 agonist medications have gained popularity due to their ability to give substantial weight loss effects and help manage other chronic conditions such as Type 2 Diabetes, they are not a magic drug that will do all the work for you.

Diet and Nutrition: Taking GLP-1 agonist medications alone will not lead to sustainable, healthy outcomes. The medication must be combined with a healthy, balanced diet that is rich in wholefoods, proteins, healthy fats and carbohydrates, while maintaining a calorie deficit that is personalised to your height, weight and activity levels. This also includes limiting processed foods and foods high in sugar. This not only aids overall weight loss but builds healthy habits that can be continued for many years to come.

Regular exercise: Exercise has a range of health benefits that will leave you feeling the best version of yourself. Incorporating regular exercise into your routine, as well as a healthy diet, when used with a GLP-1 agonist will give optimal results in weight loss and overall wellbeing.

Side effects of GLP-1 medications

No medication is without risk or side-effects, and GLP-1 agonists are no exception. Common side effects of these medications are nausea, vomiting and diarrhoea. These can lead to acute kidney injury and dehydration. GLP-1 agonist medications should not be taken without a review and prescription from a licensed healthcare professional and should be closely monitored for effectiveness and side effects.

Conclusion

GLP-1 agonist medications have gained popularity in recent years for several reasons, including effective treatment of obesity and chronic conditions. It is important to understand how these medications work and what role they play in managing a range of health conditions. It is important to always speak to your healthcare provider or doctor before starting any medication.