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.

Head hair comes in many colours, shapes and sizes, and hairstyles are often an expression of personal style or cultural identity.

Many different genes determine our hair texture, thickness and colour. But some people’s hair changes around the time of puberty, pregnancy or after chemotherapy.

So, what can cause hair to become curlier, thicker, thinner or grey?

Curly or straight? How hair follicle shape plays a role

Hair is made of keratin, a strong and insoluble protein. Each hair strand grows from its own hair follicle that extends deep into the skin.

Curly hair forms due to asymmetry of both the hair follicle and the keratin in the hair.

Follicles that produce curly hair are asymmetrical and curved and lie at an angle to the surface of the skin. This kinks the hair as it first grows.

The asymmetry of the hair follicle also causes the keratin to bunch up on one side of the hair strand. This pulls parts of the hair strand closer together into a curl, which maintains the curl as the hair continues to grow.

Follicles that are symmetrical, round and perpendicular to the skin surface produce straight hair.

Life changes, hair changes

Our hair undergoes repeated cycles throughout life, with different stages of growth and loss.

Each hair follicle contains stem cells, which multiply and grow into a hair strand.

Head hairs spend most of their time in the growth phase, which can last for several years. This is why head hair can grow so long.

Let’s look at the life of a single hair strand. After the growth phase is a transitional phase of about two weeks, where the hair strand stops growing. This is followed by a resting phase where the hair remains in the follicle for a few months before it naturally falls out.

The hair follicle remains in the skin and the stems cells grow a new hair to repeat the cycle.

Each hair on the scalp is replaced every three to five years.

Hormone changes during and after pregnancy alter the usual hair cycle

Many women notice their hair is thicker during pregnancy.

During pregnancy, high levels of oestrogen, progesterone and prolactin prolong the resting phase of the hair cycle. This means the hair stays in the hair follicle for longer, with less hair loss.

A drop in hormones a few months after delivery causes increased hair loss. This is due to all the hairs that remained in the resting phase during pregnancy falling out in a fairly synchronised way.

Hair can change around puberty, pregnancy or after chemotherapy

This is related to the genetics of hair shape, which is an example of incomplete dominance.

Incomplete dominance is when there is a middle version of a trait. For hair, we have curly hair and straight hair genes. But when someone has one curly hair gene and one straight hair gene, they can have wavy hair.

Hormonal changes that occur around puberty and pregnancy can affect the function of genes. This can cause the curly hair gene of someone with wavy hair to become more active. This can change their hair from wavy to curly.

Researchers have identified that activating specific genes can change hair in pigs from straight to curly.

Chemotherapy has very visible effects on hair. Chemotherapy kills rapidly dividing cells, including hair follicles, which causes hair loss. Chemotherapy can also have genetic effects that influence hair follicle shape. This can cause hair to regrow with a different shape for the first few cycles of hair regrowth.

Hormonal changes as we age also affect our hair

Throughout life, thyroid hormones are essential for production of keratin. Low levels of thyroid hormones can cause dry and brittle hair.

Oestrogen and androgens also regulate hair growth and loss, particularly as we age.

Balding in males is due to higher levels of androgens. In particular, high dihydrotestosterone (sometimes shortened to DHT), which is produced in the body from testosterone, has a role in male pattern baldness.

Some women experience female pattern hair loss. This is caused by a combination of genetic factors plus lower levels of oestrogen and higher androgens after menopause. The hair follicles become smaller and smaller until they no longer produce hairs.

Reduced function of the cells that produce melanin (the pigment that gives our hair colour) is what causes greying.

Theresa Larkin, Associate professor of Medical Sciences, University of Wollongong

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