Fourteen years ago, the older drug cousin of semaglutide (Ozempic and Wegovy) came onto the market. The drug, liraglutide, is sold under the brand names Victoza and Saxenda.

Patents for Victoza and Saxenda have now expried. So other drug companies are working to develop “generic” versions. These are likely be a fraction of current cost, which is around A$400 a month.

So how does liraglutide compare with semaglutide?

How do these drugs work?

Liraglutide was not originally developed as a weight-loss treatment. Like semaglutide (Ozempic), it originally treated type 2 diabetes.

The class of drugs liraglutide and semaglutide belong to are known as GLP-1 mimetics, meaning they mimic the natural hormone GLP-1. This hormone is released from your small intestines in response to food and acts in several ways to improve the way your body handles glucose (sugar).

How do they stop hunger?

Liraglutide acts in several regions of the unconscious part of your brain, specifically the hypothalamus, which controls metabolism, and parts of the brain stem responsible for communicating your body’s nutrient status to the hypothalamus.

Its actions here appear to reduce hunger in two different ways. First, it helps you to feel full earlier, making smaller meals more satisfying. Second, it alters your “motivational salience” towards food, meaning it reduces the amount of food you seek out.

Liraglutide’s original formulation, designed to treat type 2 diabetes, was marketed as Victoza. Its ability to cause weight loss was evident soon after it entered the market.

Shortly after, a stronger formulation, called Saxenda, was released, which was intended for weight loss in people with obesity.

How much weight can you lose with liraglutide?

People respond differently and will lose different amounts of weight. But here, we’ll note the average weight loss users can expect. Some will lose more (sometimes much more), others will lose less, and a small proportion won’t respond.

The first GLP-1 mimicking drug was exenatide (Bayetta). It’s still available for treating type 2 diabetes, but there are currently no generics. Exenatide does provide some weight loss, but this is quite modest, typically around 3-5% of body weight.

For liraglutide, those using the drug to treat obesity will use the stronger one (Saxenda), which typically gives about 10% weight loss.

Semaglutide, with the stronger formulation called Wegovy, typically results in 15% weight loss.

The newest GLP-1 mimicking drug on the market, tirzepatide (Mounjaro for type 2 diabetes and Zepbound for weight loss), results in weight loss of around 25% of body weight.

What happens when you stop taking them?

Despite the effectiveness of these medications in helping with weight loss, they do not appear to change people’s weight set-point.

So in many cases, when people stop taking them, they experience a rebound toward their original weight.

What is the dose and how often do you need to take it?

Liraglutide (Victoza) for type 2 diabetes is exactly the same drug as Saxenda for weight loss, but Saxenda is a higher dose.

Although the target for each formulation is the same (the GLP-1 receptor), for glucose control in type 2 diabetes, liraglutide has to (mainly) reach the pancreas.

But to achieve weight loss, it has to reach parts of the brain. This means crossing the blood-brain barrier – and not all of it makes it, meaning more has to be taken.

All the current formulations of GLP-1 mimicking drug are injectables. This won’t change when liraglutide generics hit the market.

However, they differ in how frequently they need to be injected. Liraglutide is a once-daily injection, whereas semaglutide and tirzepatide are once-weekly. (That makes semaglutide and tirzepatide much more attractive, but we won’t see semaglutide as a generic until 2033.)

What are the side effects?

Because all these medicines have the same target in the body, they mostly have the same side effects.

The most common are a range of gastrointestinal upsets including nausea, vomiting, bloating, constipation and diarrhoea. These occur, in part, because these medications slow the movement of food out of the stomach, but are generally managed by increasing the dose slowly.

Recent clinical data suggests the slowing in emptying of the stomach can be problematic for some people, and may increase the risk of of food entering the lungs during operations, so it is important to let your doctor know if you are taking any of these drugs.

Because these are injectables, they can also lead to injection-site reactions.

During clinical trials, there were some reports of thyroid disease and pancreatitis (inflammation of the pancreas). However, it is not clear that these can be attributed to GLP-1 mimicking drugs.

In animals, GLP-1 mimicking drugs drugs have been found to negatively alter the growth of the embryo. There is currently no controlled clinical trial data on their use during pregnancy, but based on animal data, these medicines should not be used during pregnancy.

Who can use them?

The GLP-1 mimicking drugs for weight loss (Wegovy, Saxenda, Zepbound/Mounjaro) are approved for use by people with obesity and are meant to only be used in conjunction with diet and exercise.

These drugs must be prescribed by a doctor and for obesity are not covered by the Pharmaceutical Benefits Scheme, which is one of the reasons why they are expensive. But in time, generic versions of liraglutide are likely to be more affordable.

Sebastian Furness, ARC Future Fellow, School of Biomedical Sciences, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

What’s the difference? is a new editorial product that explains the similarities and differences between commonly confused health and medical terms, and why they matter.

The terms “shyness” and “social anxiety” are often used interchangeably because they both involve feeling uncomfortable in social situations.

However, feeling shy, or having a shy personality, is not the same as experiencing social anxiety (short for “social anxiety disorder”).

Here are some of the similarities and differences, and what the distinction means.

How are they similar?

It can be normal to feel nervous or even stressed in new social situations or when interacting with new people. And everyone differs in how comfortable they feel when interacting with others.

For people who are shy or socially anxious, social situations can be very uncomfortable, stressful or even threatening. There can be a strong desire to avoid these situations.

People who are shy or socially anxious may respond with “flight” (by withdrawing from the situation or avoiding it entirely), “freeze” (by detaching themselves or feeling disconnected from their body), or “fawn” (by trying to appease or placate others).

A complex interaction of biological and environmental factors is also thought to influence the development of shyness and social anxiety.

For example, both shy children and adults with social anxiety have neural circuits that respond strongly to stressful social situations, such as being excluded or left out.

People who are shy or socially anxious commonly report physical symptoms of stress in certain situations, or even when anticipating them. These include sweating, blushing, trembling, an increased heart rate or hyperventilation.

How are they different?

Social anxiety is a diagnosable mental health condition and is an example of an anxiety disorder.

For people who struggle with social anxiety, social situations – including social interactions, being observed and performing in front of others – trigger intense fear or anxiety about being judged, criticised or rejected.

To be diagnosed with social anxiety disorder, social anxiety needs to be persistent (lasting more than six months) and have a significant negative impact on important areas of life such as work, school, relationships, and identity or sense of self.

Many adults with social anxiety report feeling shy, timid and lacking in confidence when they were a child. However, not all shy children go on to develop social anxiety. Also, feeling shy does not necessarily mean a person meets the criteria for social anxiety disorder.

People vary in how shy or outgoing they are, depending on where they are, who they are with and how comfortable they feel in the situation. This is particularly true for children, who sometimes appear reserved and shy with strangers and peers, and outgoing with known and trusted adults.

Individual differences in temperament, personality traits, early childhood experiences, family upbringing and environment, and parenting style, can also influence the extent to which people feel shy across social situations.

However, people with social anxiety have overwhelming fears about embarrassing themselves or being negatively judged by others; they experience these fears consistently and across multiple social situations.

The intensity of this fear or anxiety often leads people to avoid situations. If avoiding a situation is not possible, they may engage in safety behaviours, such as looking at their phone, wearing sunglasses or rehearsing conversation topics.

The effect social anxiety can have on a person’s life can be far-reaching. It may include low self-esteem, breakdown of friendships or romantic relationships, difficulties pursuing and progressing in a career, and dropping out of study.

The impact this has on a person’s ability to lead a meaningful and fulfilling life, and the distress this causes, differentiates social anxiety from shyness.

Children can show similar signs or symptoms of social anxiety to adults. But they may also feel upset and teary, irritable, have temper tantrums, cling to their parents, or refuse to speak in certain situations.

If left untreated, social anxiety can set children and young people up for a future of missed opportunities, so early intervention is key. With professional and parental support, patience and guidance, children can be taught strategies to overcome social anxiety.

Why does the distinction matter?

Social anxiety disorder is a mental health condition that persists for people who do not receive adequate support or treatment.

Without treatment, it can lead to difficulties in education and at work, and in developing meaningful relationships.

Receiving a diagnosis of social anxiety disorder can be validating for some people as it recognises the level of distress and that its impact is more intense than shyness.

A diagnosis can also be an important first step in accessing appropriate, evidence-based treatment.

Different people have different support needs. However, clinical practice guidelines recommend cognitive-behavioural therapy (a kind of psychological therapy that teaches people practical coping skills). This is often used with exposure therapy (a kind of psychological therapy that helps people face their fears by breaking them down into a series of step-by-step activities). This combination is effective in-person, online and in brief treatments.

For more support or further reading

Online resources about social anxiety include:

• This Way Up’s online program for managing excessive shyness and fear of social situations
• Beyond Blue’s resources on social anxiety
• a guide to looking after yourself if you have social anxiety, from the Western Australian health department
• social anxiety online program for children and teens from the University of Queensland
• inroads, a self-guided online program for young adults who drink alcohol to manage their anxiety.

We thank the Black Dog Institute Lived Experience Advisory Network members for providing feedback and input for this article and our research.

Kayla Steele, Postdoctoral research fellow and clinical psychologist, UNSW Sydney and Jill Newby, Professor, NHMRC Emerging Leader & Clinical Psychologist, UNSW Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.