Semaglutide is making waves online for its potential to help people lose weight. Sold under the brand names Ozempic and Wegovy, this drug can supposedly help you shed over 10 per cent of body weight and counts Elon Musk among its users.
But what does this drug actually do, who is it suitable for, and are there any side effects? With Hollywood's favourite 'skinny jab' now on its way to the UK, we've answered all these questions and more with a guide on everything you need to know about semaglutide and the names it's sold under.
What is Ozempic?
Ozempic and Wegovy are brand names for medication made from the drug semaglutide. Both are administered through injection and produced by the Danish pharmaceutical giant Novo Nordisk.
Ozempic has been used to treat type 2 diabetes for some years, while Wegovy is the new weight loss version of the drug coming to the UK. The difference between the two is that Wegovy has a higher concentration of semaglutide.
How does Ozempic work?
Semaglutide replicates a hormone called GLP-1 (glucagon-like peptide 1) secreted by the gut after eating. It tells the pancreas to increase insulin, hence why semaglutide was designed to treat type 2 diabetes.
However, GLP-1 also sends signals to the brain that make us feel full. Semaglutide can thus be used to suppress appetite and alleviate some of the ill effects of dieting.
"When you lose weight through a diet, you then start to feel hungry, miserable, tired and all the rest of it," Dr Simon Cork, a senior lecturer at Anglia Ruskin University, told BBC Science Focus. "What semaglutide does is it prevents the biological response to weight loss."
Does semaglutide cause weight loss?
The drug helps people lose weight but doesn't directly cause weight loss. "Semaglutide will not cause you to lose weight, but what it will do is sustain weight loss that is achieved through diet and exercise," Cork said.
A large trial of 1,961 overweight or obese adults found that patients using semaglutide lost and average of 15.3 kg, or 2.4 stone, while those in a placebo group lost 2.6 kg on average. Both groups also received diet and lifestyle advice.
However, weight loss acquired with the assistance of semaglutide is not necessarily permanent. A follow-up trial found that one year after the withdrawal of semaglutide injections, participants had regained two-thirds of their lost weight. It's also not clear how effective the drug may be without the diet and exercise advice.
Dr Margaret McCartney, a general practitioner based in Glasgow, has also questioned how much of a difference semaglutide could make to large populations, with the potential for many people to 'swiftly gain weight' after two years of free treatment on the NHS unless they can afford to pay for semaglutide privately.
"Given the social gradient related to obesity, it might be that people with the most to benefit from the drug would not be able to afford it,' McCartney wrote in a column for the BMJ.
Where are Ozempic and Wegovy available?
The weight loss version of semaglutide (Wegovy) is not available in the UK yet, but it's coming. High street chemists have begun promoting the drug, and semaglutide will soon be available in England on the NHS for weight loss, but there are certain conditions.
The National Institute for Health and Care Excellence (NICE) recommended the drug be available to those with a body mass index of at least 35 (over 30 is obese) and one weight-related health condition. Furthermore, Wegovy will only be prescribed on the NHS for a maximum of two years within a specialist weight management service. Most of these are based in hospitals and, according to government figures, would give around 35,000 people access to the drug.
"Semaglutide won’t be available to everyone," Helen Knight, director of medicines evaluation at NICE, said in March. "Our committee has made specific recommendations to ensure it remains value for money for the taxpayer, and it can only be used for a maximum of two years."
On June 6, the UK government announced a £40 million pilot scheme to explore how approved drugs like semaglutide can be made available to more people. This includes the potential for expanding specialist weight management services outside of hospitals and allowing access to the drugs through GPs.
Wegovy will be available on prescription from UK High Street chemists, with an anticipated launch in Spring 2023. The cost of which has yet to be revealed.
Cork told BBC Science Focus that licensing the drug for obesity treatment on the NHS is a positive step with the scientific community clear that Severe obesity is a disease that needs to be managed through drugs. However, Cork isn't sure about semaglutide making its way to the high street.
"I have reservations about it being available privately on the high street because I think it is a drug that needs to be monitored and managed very carefully," he said.
What are the side effects of Semaglutide?
Semaglutide side effects can include nausea, vomiting, diarrhoea and constipation. The US National Library of Medicine's MedlinePlus website also warns that a semaglutide injection might increase the risk of thyroid gland tumours, noting that the risks of taking the medication should be discussed with a doctor.
The New York Times reported that one extreme risk of taking Ozempic is that some people suffer such a loss in appetite that they can become malnourished. This highlights the importance of maintaining a good diet alongside the medication.
Note this is just a snippet of the potential side effects of semaglutide. There are many more. Cork also told BBC Science Focus that "we don't have any data on the long-term safety of this drug."
Suicide risk
In July 2023, the European Medicines Agency announced it is reviewing data on the potential risk of suicidal thoughts and thoughts of self-harm associated with GLP-1 medicines, including Ozempic and Wegovy.
This followed reports flagged by the Icelandic medicines agency of suicidal thoughts and self-injury with people using semaglutide and liraglutide, another GLP-1 drug.
The European Medicines Agency said it is analysing around 150 reports of possible cases of suicidal thoughts and self-injury.
However, the medicines are widely used, and the agency also stated: “It is not yet clear whether the reported cases are linked to the medicines themselves or to the patients’ underlying conditions or other factors.”
Will Ozempic become a mental health drug?
Reports have emerged that Ozempic may become a game-changing anti-anxiety drug with plenty of mental health benefits, including reducing addictive behaviours and improving a person's stress and depression.
GLP-1 is released naturally in the brain and can interact with reward pathways. By mimicking GLP-1, Ozempec may have a positive impact on cravings and mental health. Furthermore, weight loss can boost self-confidence, and the stigma associated with weight can result in someone shedding pounds to feel better.
Repurposing a drug to treat other health issues isn't an uncommon phenomenon, with semaglutide already being used to tackle type 2 diabetes and obesity. However, further research is needed to explore other potential benefits like treating mental health.
About our expert, Dr Simon Cork
Dr Simon Cork is a senior lecturer in physiology at Anglia Ruskin University, and an honorary lecturer at Imperial College London. He had a specialist interest in obesity, the gut-brain axis, and the regulation of appetite. His research has been published in journals including the Journal Of Neural Engineering, Molecular Metabolism, and Neuroscience.
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