The weight-loss drug Wegovy is now available in Australia.

Wegovy is administered as a once-weekly injection and is approved specifically for weight management. It’s intended to be used in combination with a reduced-energy diet and increased physical activity.

So how does Wegovy work and how much weight can you expect to lose while taking it? And what are the potential risks – and costs – for those who use it?

Let’s look at what the science says.

What is Wegovy?

Wegovy is a brand name for the medication semaglutide. Semaglutide is a glucagon-like peptide-1 receptor agonist (GLP-1RA). This means it makes your body’s own glucagon-like peptide-1 hormone, called GLP-1 for short, work better.

Normally when you eat, the body releases the GLP-1 hormone which helps signal to your brain that you are full. Semaglutides enhance this effect, leading to a feeling of fullness, even when you haven’t eaten.

Another role of GLP-1 is to stimulate the body to produce more insulin, a hormone which helps lower the level of glucose (sugar) in the blood. That’s why semaglutides have been used for several years to treat type 2 diabetes.

How does Wegovy differ from Ozempic?

Like Wegovy, Ozempic is a semaglutide. The way Wegovy and Ozempic work in the body are essentially the same. They’re made by the same pharmaceutical company, Novo Nordisk.

But there are two differences:

1) They are approved for two different (but related) reasons.

In Australia (and the United States), Ozempic is approved for use to improve blood glucose levels in adults with type 2 diabetes. By managing blood glucose levels effectively, the medication aims to reduce the risk of major complications, such as heart disease.

Wegovy is approved for use alongside diet and exercise for people with a body mass index (BMI) of 30 or greater, or 27 or greater but with other conditions such as high blood pressure.

Wegovy can also be used in people aged 12 years and older. Like Ozempic, Wegovy aims to reduce the risk of future health complications, including heart disease.

2) They are both injected but come in different strengths.

Ozempic is available in pre-loaded single-dose pens with varying dosages of 0.25 mg, 0.5 mg, 1 mg, or 2 mg per injection. The dose can be slowly increased, up to a maximum of 2 mg per week, if needed.

Wegovy is available in prefilled single-dose pens with doses of 0.25 mg, 0.5 mg, 1 mg, 1.7 mg, or 2.4 mg. The treatment starts with a dose of 0.25 mg once weekly for four weeks, after which the dose is gradually increased until reaching a maintenance dose of 2.4 mg weekly.

While it’s unknown what the impact of Wegovy’s introduction will be on Ozempic’s availability, Ozempic is still anticipated to be in low supply for the remainder of 2024.

Is Wegovy effective for weight loss?

Given Wegovy is a semaglutide, there is very strong evidence it can help people lose weight and maintain this weight loss.

A recent study found that over four years, participants taking Wevovy as indicated experienced an average weight loss of 10.2% body weight and a reduction in waist circumference of 7.7cm.

For those who stop taking the medication, analyses have shown that about two-thirds of weight lost is regained.

What are the side effects of Wegovy?

The most common side effects are nausea and vomiting.

However, other serious side effects are also possible because of the whole-of-body impact of the medication. Thyroid tumours and cancer have been detected as a risk in animal studies, yet are rarely seen in human scientific literature.

In the four-year Wegovy trial, 16.6% of participants who received Wegovy (1,461 people) experienced an adverse event that led to them permanently discontinuing their use of the medication. This was higher than the 8.2% of participants (718 people) who received the placebo (with no active ingredient).

Side effects included gastrointestinal disorders (including nausea and vomiting), which affected 10% of people who used Wegovy compared to 2% of people who used the placebo.

Gallbladder-related disorders occurred in 2.8% of people who used Wegovy, and 2.3% of people who received the placebo.

Recently, concerns about suicidal thoughts and behaviours have been raised, after a global analysis reviewed more than 36 million reports of adverse events from semaglutide (Ozempic or Wegovy) since 2000.

There were 107 reports of suicidal thoughts and self-harm among people taking semaglutide, sadly including six actual deaths. When people stopped the medication, 62.5% found the thoughts went away. What we don’t know is whether dose, weight loss, or previous mental health status or use of antidepressants had a role to play.

Finally, concerns are growing about the negative effect of semaglutides on our social and emotional connection with food. Anecdotal and scientific evidence suggests people who use semaglutides significantly reduce their daily dietary intake (as anticipated) by skipping meals and avoiding social occasions – not very enjoyable for people and their loved ones.

How can people access Wegovy?

Wegovy is available for purchase at pharmacists with a prescription from a doctor.

But there is a hefty price tag. Wegovy is not currently subsidised through the Pharmaceutical Benefits Scheme, leaving patients to cover the cost. The current cost is estimated at around A$460 per month dose.

If you’re considering Wegovy, make an appointment with your doctor for individual advice.

Lauren Ball, Professor of Community Health and Wellbeing, The University of Queensland and Emily Burch, Accredited Practising Dietitian and Lecturer, Southern Cross University

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

Exercise training while wearing a weighted vest is undergoing somewhat of a renaissance. Social media posts and trainers are promoting them as a potential strategy for improving fitness and health.

Exercising with additional weight attached to the body is nothing new. This idea has been used with soldiers for many centuries if not millennia – think long hikes with a heavy pack.

The modern weighted vest comes in a range of designs that are more comfortable and can be adjusted in terms of the weight added. But could one be helpful for you?

What the research says

One of the earliest research studies, reported in 1993, followed 36 older people wearing weighted vests during a weekly exercise class and at home over a 20-week period. Wear was associated with improvements in bone health, pain and physical function.

Since then, dozens of papers have evaluated the exercise effects of wearing a weighted vest, reporting a range of benefits.

Not surprisingly, exercise with a weighted vest increases physiological stress – or how hard the body has to work – as shown by increased oxygen uptake, heart rate, carbohydrate utilisation and energy expenditure.

Adding weight equal to 10% of body weight is effective. But it doesn’t appear the body works significantly harder when wearing 5% extra weight compared to body weight alone.

Does more load mean greater injury risk?

A small 2021 study suggested additional weights don’t alter the biomechanics of walking or running. These are important considerations for lower-limb injury risk.

The safety considerations of exercising with weighted vests have also been reported in a biomechanical study of treadmill running with added weight of 1% to 10% of body weight.

While physiological demand (indicated by heart rate) was higher with additional weight and the muscular forces greater, running motion was not negatively affected.

To date no research studies have reported increased injuries due to wearing weighted vests for recreational exercise. However a 2018 clinical study on weight loss in people with obesity found back pain in 25% of those wearing such vests. Whether this can be translated to recreational use in people who don’t have obesity is difficult to say. As always, if pain or discomfort is experienced then you should reduce the weight or stop vest training.

Better for weight loss or bone health?

While wearing a weighted vest increases the energy expenditure of aerobic and resistance exercise, research to show it leads to greater fat loss or retaining muscle mass is somewhat inconclusive.

One older study investigated treadmill walking for 30 minutes, three times a week in postmenopausal women with osteoporosis. The researchers found greater fat loss and muscle gain in the participants who wore a weighted vest (at 4–8% body weight). But subsequent research in obese older adults could not show greater fat loss in participants who wore weighted vests for an average of 6.7 hours per day.

There has been considerable interest in the use of weighted vests to improve bone health in older people. One 2003 study reported significant improvements in bone density in a group of older women over 32 weeks of weighted vest walking and strength training compared to a sedentary control group.

But a 2012 study found no difference in bone metabolism between groups of postmenopausal women with osteoporosis walking on a treadmill with or without a weighted vest.

Making progress

As with any exercise, there is a risk of injury if it is not done correctly. But the risk of weighted vest training appears low and can be managed with appropriate exercise progression and technique.

If you are new to training, then the priority should be to simply start exercising and not complicate it with wearing a weighted vest. The use of body weight alone will be sufficient to get you on the path to considerable gains in fitness.

Once you have a good foundation of strength, aerobic fitness and resilience for muscles, joints and bones, using a weighted vest could provide greater loading intensity as well as variation.

It is important to start with a lighter weight (such as 5% bodyweight) and build to no more than 10% body weight for ground impact exercises such as running, jogging or walking.

For resistance training such as squats, push-ups or chin-ups, progression can be achieved by increasing loads and adjusting the number of repetitions for each set to around 10 to 15. So, heavier loads but fewer repetitions, then building up to increase the load over time.

While weighted vests can be used for resistance training, it is probably easier and more convenient to use barbells, dumbbells, kettle bells or weighted bags.

The bottom line

Weighted vest training is just one tool in an absolute plethora of equipment, techniques and systems. Yes, walking or jogging with around 10% extra body weight increases energy expenditure and intensity. But training for a little bit longer or at a higher intensity can achieve similar results.

There may be benefits for bone health in wearing a weighted vest during ground-based exercise such as walking or jogging. But similar or greater stimulus to bone growth can be achieved by resistance training or even the introduction of impact training such as hopping, skipping or bounding.

Exercising with a weighted vest likely won’t increase your injury risk. But it must be approached intelligently considering fitness level, existing and previous injuries, and appropriate progression for intensity and repetition.

Rob Newton, Professor of Exercise Medicine, Edith Cowan University

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