What Are GLP-1 Medications?

Medical disclaimer: This article is for general educational purposes only. It does not provide personal medical advice, diagnosis or treatment recommendations. Speak with a qualified healthcare professional before starting, stopping or changing any prescription medicine.

A few years ago, most people had never heard the term GLP-1.

Now it is everywhere. It comes up in group chats, across social media, at the gym and around the dinner table. One person knows someone taking Ozempic. Another has heard Mounjaro works better. Someone else scrolls TikTok and is inundated with videos about retatrutide, even though it is still being researched.

Before long, the names start to blur together.

You hear about someone losing weight quickly. You see another before-and-after video. Then a new peptide appears in your feed, followed by someone claiming it is the next big thing.

It is easy to get pulled into the conversation before really understanding what any of it means.

What is GLP-1? What does it actually do? Why are Ozempic, Mounjaro and retatrutide all spoken about in the same breath?

Before comparing names, results or what someone on your feed is doing, it helps to understand what GLP-1 actually is.

GLP-1 stands for glucagon-like peptide-1, and while the name sounds complicated, the basic idea is relatively simple.

GLP-1 is a naturally occurring hormone that plays a role in appetite and blood glucose regulation. After you eat, it becomes part of the communication happening between your digestive system, brain and pancreas.

Think about reaching the end of a meal and eventually getting the message that you have had enough. There are several hormones and biological processes involved in creating that feeling, and GLP-1 is one part of that larger conversation.

GLP-1 also helps support the release of insulin when blood glucose rises. This connection is one reason it has long been relevant in conversations around type 2 diabetes, blood glucose management and insulin resistance.

Natural GLP-1 does not remain active in the body for very long. Researchers developed medications that could act on the same biological pathway for longer periods of time.

That is how we get from a hormone most people had never heard of to some of the most talked-about prescription medicines in the world.

For many people, losing weight is not simply a matter of knowing what to eat.

Someone can understand calories, know what a balanced meal looks like and have every intention of eating differently, while still experiencing hunger, cravings and persistent thoughts about food.

You may have heard this described as “food noise.” While food noise is not a formal medical diagnosis, the phrase is commonly used to describe frequent or persistent thoughts about food, eating and what someone might eat next.

GLP-1 medications can influence some of the biological signals involved in appetite. Depending on the medicine, this can help increase feelings of fullness, reduce hunger and make smaller amounts of food feel more satisfying.

When someone feels satisfied with less food, maintaining a calorie deficit may become easier.

This is an important distinction because these medicines do not directly “melt” body fat. Instead, they influence some of the biological processes that can affect appetite and food intake.

For someone who has spent years feeling as though they are constantly battling their appetite, that can make the experience of weight loss feel very different.

This is also where all of the names you keep hearing begin to enter the conversation.

You do not need to memorise a pharmaceutical family tree to understand the GLP-1 conversation.

Ozempic and Wegovy both contain semaglutide and act on the GLP-1 receptor. Mounjaro contains tirzepatide and acts on both GLP-1 and GIP receptors. You may also hear names such as Saxenda and Trulicity.

These medicines sit within the same broader conversation, but they are not interchangeable versions of the same treatment. They can contain different active ingredients, act on different pathways and have different approved uses.

Social media can quickly turn this into a debate about whether Ozempic or Mounjaro is “better.” In reality, whether any prescription medicine is appropriate for someone depends on their health, medical history, the reason the medicine is being considered and the judgement of their healthcare professional.

If you spend enough time looking into GLP-1 medications online, another word will also start appearing everywhere.

That word is peptides.

Peptides have become one of the biggest talking points across health, fitness, weight loss and longevity content.

The name sounds complicated, but the basic definition is straightforward.

Peptides are short chains of amino acids. Amino acids are also the building blocks that join together in larger chains to form proteins.

The human body naturally produces many different peptides, and some of them act as biological messengers involved in processes such as appetite, metabolism and growth.

Some medicines are peptide-based too.

Semaglutide is a GLP-1 analogue, which means the active ingredient in Ozempic is a peptide-based medicine designed to act on the GLP-1 receptor.

However, there is an important distinction that can easily get lost online.

Being described as a peptide does not automatically mean something is natural, approved or safe.

The growing interest in peptides has also led to unapproved products being promoted through websites and social media. These products may not have been assessed for safety, quality or effectiveness, and it may be difficult to know exactly what they contain or how they were manufactured.

One of the names sitting right in the middle of that conversation is retatrutide.

Retatrutide is an investigational treatment that acts on three receptors, including GLP-1, GIP and glucagon.

This is why you may hear it described as a triple receptor agonist.

Early research into retatrutide and body weight attracted significant attention, and further clinical trials are continuing to investigate its effects and safety.

Retatrutide is not currently approved for general use in Australia.

However, there is another part of the research that deserves attention because researchers are not only asking how much weight someone loses. They are also looking at what that lost weight is actually made up of.

This matters because significant weight loss can involve changes in both body fat and lean mass.

Research into retatrutide has found that much of the weight lost came from body fat, but some lean mass was lost too. So, while retatrutide has shown promising results for weight loss, current research does not suggest that it protects muscle any better than other weight-loss treatments.

Instead, the research highlights a much bigger question that applies across weight loss more generally.

The number on the scales does not tell you everything about what is happening inside the body.

Before we move into that conversation, there is another side of GLP-1 medications that deserves attention.

GLP-1 medications are prescription medicines, which means potential benefits are only one side of the conversation.

Common side effects can include nausea, vomiting, diarrhoea, constipation and abdominal discomfort. Different medicines can also have their own warnings, precautions, contraindications and potential interactions.

Less common but more serious risks can also occur, which is one reason these medicines require appropriate medical assessment and supervision.

Safety information can also change as more research becomes available and more people use these medicines over longer periods of time.

This does not mean GLP-1 medications should be framed as either “good” or “bad.”

It means they should be treated as medical treatments rather than another wellness trend to follow simply because they suddenly appear everywhere online.

The potential benefits, risks and suitability can differ considerably between individuals.

This is why the conversation should not end with how many kilograms someone lost.

Imagine that someone loses 15 kilograms.

On paper, the result sounds simple because 15 kilograms have disappeared from the scales.

However, the scales cannot tell you how that person’s strength has changed. They cannot tell you how much of that change came from body fat or lean tissue. They also cannot tell you whether someone is eating enough protein, getting the nutrients they need or feeling physically strong and capable.

This is where body composition becomes an important part of the conversation.

Research into GLP-1-based weight-loss treatments has shown that reductions in body weight can include reductions in both fat mass and lean mass. This does not mean that everyone taking a GLP-1 medication will experience significant muscle loss, and lean tissue can also decrease during weight loss without medication.

However, it does mean that someone who is focused on losing weight may also want to think about what they are trying to maintain along the way.

Maintaining muscle, strength, adequate nutrition, energy and physical capability can all remain important parts of the bigger health picture.

This is where the healthy fundamentals become especially relevant.

There is an interesting contradiction at the centre of this conversation.

Someone may have spent years struggling to eat less, only to find that once their appetite changes significantly, the challenge becomes making sure the food they are eating still gives their body what it needs.

When someone becomes full sooner and eats less overall, there are fewer opportunities throughout the day to consume protein, fibre, vitamins, minerals and fluids.

This means food quality still matters, even when food quantity decreases.

A balanced diet that includes vegetables, fruit, wholegrains, protein-rich foods, healthy fats and adequate fluids remains an important part of supporting overall health.

Medication can change appetite, but it does not change the body’s need for nutrition.

When the conversation turns to maintaining muscle during weight loss, protein naturally becomes part of it.

Protein provides amino acids that the body uses to build, repair and maintain tissues, including muscle.

When overall food intake becomes smaller, consuming enough protein across the day may require more consideration. This does not mean everyone needs to dramatically increase their protein intake or replace meals with protein shakes.

Whole-food sources such as eggs, yoghurt, fish, chicken, lean meat, tofu, legumes and other protein-rich foods can all contribute to daily protein intake.

For some people, protein powder may also provide a convenient way to add protein when appetite is lower or eating a larger meal feels difficult.

Individual protein requirements can vary depending on factors such as body size, age, activity levels, overall diet and medical circumstances.

The broader point is simple because supporting muscle still matters when someone is trying to lose weight.

Nutrition gives the body the building blocks it needs, while movement gives the body a reason to use them. Resistance training can help support muscle, strength and physical function during weight loss, but your muscles are not the only thing worth thinking about.

When someone loses a significant amount of weight, bone density can also be affected. This is becoming an important part of the conversation around GLP-1 medications and weight loss more broadly, because maintaining strong bones matters just as much as maintaining muscle. Resistance and weight-bearing exercise can help support bone density, which becomes increasingly important as we get older and the risk of osteoporosis and fractures increases.

This does not mean everyone needs to suddenly start training like a bodybuilder. Lifting weights, using resistance bands, doing bodyweight exercises and other forms of weight-bearing movement can all help support muscle and bone health, depending on the individual and their circumstances.

Strength also matters far beyond what happens in the gym. Being able to carry groceries, climb stairs, get off the floor, play sport, keep up with your children and remain physically independent as you get older all rely on maintaining a strong and capable body.

This is another reason the weight-loss conversation should look beyond the number on the scales. Maintaining muscle, supporting bone health and staying physically capable are all part of the bigger picture.

GLP-1 has gone from something most people had never heard of to one of the biggest health conversations online.

When something becomes popular that quickly, it is easy to jump straight to questions about whether you should take it, which medicine is best or how much weight someone could lose.

Before any of those questions, there is a more useful place to begin.

You should first understand what GLP-1 is and what it actually does.

There is real science behind these treatments, but there are also real risks, unanswered questions and individual considerations that cannot be captured by a transformation video or a social media comment section.

Whether medication is part of someone’s story or not, the healthy foundations remain relevant. Losing weight may be one outcome, but supporting the body you are losing that weight for matters too.