What are the health risks of using Ozempic for weight loss?

When it was reported on Wednesday morning that television personality Oprah Winfrey had collapsed and been rushed to hospital, many people assumed her health condition was linked to her use of weight-loss medications like Ozempic.

But was this assumption fair? What exactly are the health risks associated with drugs such as semaglutide, which are increasingly being taken for weight loss?

Oprah Winfrey has a new TV special on weight loss drugs.Credit: AP

Winfrey’s close friend Gayle King confirmed that she had been hospitalised, telling CBS Mornings, “She had some kind of stomach thing – stomach flu – stuff was coming out of both ends. I won’t get too graphic.”

In December last year, Winfrey revealed she had been taking prescription medication to manage her weight, making her part of a growing cohort of Hollywood stars who are either rumoured to have, or who have admitted to, taking the class of drug. While Ozempic is not approved for weight loss in Australia, its off-label prescription is on the rise, something the TGA said it would ban in September this year.

Gastrointestinal issues

Several studies have shown a link between GLP-1 agonists, the class of drugs that include Ozempic, and gastrointestinal issues. One study from October 2023 found that semaglutide and liraglutide were associated with increased risks of pancreatitis, gastroparesis and bowel obstruction.

In another US-based clinical trial, almost half of participants reported experiencing adverse effects, with nausea and vomiting being the most commonly reported symptom, followed by diarrhoea and fatigue.

While Dr Ian Musgrave, a senior lecturer in pharmacology at the University of Adelaide, agrees that some of Winfrey’s symptoms align with those reported by GLP-1 users, he says it is more likely she suffered from a virus like norovirus or rotavirus.

“[The gastroinstestinal symptoms associated with GLP-1s] are typically mild and transient. So basically, very unpleasant but not something you would get hospitalised for [as Winfrey has].”

He explains that because these drugs work by acting on the gastrointestinal tract, some gastrointestinal side effects are to be expected. He says these are typically mild and temporary, and should not be overstated. In rare cases they can cause more serious problems, and he says those with a history of gastrointestinal conditions such as pancreatitis should be cautious and always consult a medical professional.

Musgrave says for most people, the benefits of such medications outweigh potential side effects. “Because they’re so effective at controlling blood glucose as well as causing weight loss, and have very important effects in reducing things like cardiovascular risk, the risk benefit for people with type two diabetes or obesity is firmly in the benefit,” he says.

The effects of rapid or yo-yoing weight loss

On social media, “Ozempic face” is said to be one of the most pronounced effects of the drug, characterised by a noticeably more hollow and aged face caused by losing weight quickly. But the effects of rapid weight loss goes beyond chiselled cheekbones.

Dr Natasha Yates, a GP and clinical tutor at Bond University, says it’s important to remember that most people will regain the weight once they stop taking the drug. She adds that the effects of rapid weight loss or fluctuating weight can put a great deal of stress on the body.

“It does put a strain on the cardiovascular system. Interestingly, it tends to put less of a strain on people who are obese or morbidly obese, but who are overweight, which is a caution to people who might just be wanting to lose a few kilos to look better rather than from a health perspective,” she says.

Yates says that “the most healthy way to lose weight is to do so fairly slowly, and to keep it off over a prolonged period so that your body develops a new set point”.

Ageing and long-term effects

Associate Professor David Scott, of Deakin University’s Institute for Physical Activity and Nutrition, is concerned about the effect that short-term weight loss can have on muscle mass and bone density.

While there has yet to be research on the long-term effects of semaglutide, he says studies conducted on weight loss over 12 or 24 months show most people lose more than just fat.

“When you lose a significant amount of weight on these drugs, about 30 to 40 per cent of that is muscle,” Scott says. “We also know that within about 12 months of stopping these drugs, people regain around 70 per cent of the weight they lost. And I suspect that very little, if any, of that would be muscle.”

He says this is concerning as it suggests a lower composition of muscle in the long term, which we know to be important for health as we age, and so weight-loss drugs need to be accompanied by healthy lifestyle changes.

“Once they come off the drug, we need to be making sure that people are doing effective exercise and consuming the right nutrition to preserve muscle and bone,” says Scott.

‘[Ozempic] makes it harder for them to go out … you don’t actually deal with the psychological reasons someone might be overeating.’

GP Dr Natasha Yates

Yates agrees that those taking such drugs for weight loss must focus on a nutritionally dense diet. “If they’re simply losing weight by reducing calories, they’re not feeding their cells and growing them in a healthy way,” she says. “And then in the long term, of course, nutritional deficiencies can be a big problem.”

Social and psychological effects

As a GP, Yates is particularly concerned by the social and psychological effects of drugs like Ozempic.

“It’s having an impact on my patients in the way they interact with food,” she says. “It reduces their pleasure in eating, and it makes it harder for them to go out and socialise, which are not good things if you don’t actually deal with the psychological reasons someone might be overeating in the first place.

Drugs such as Ozempic are leaving doctors with the challenge of deciding if it can help weight loss.Credit: AP

“The holistic approach we try and take when someone loses weight is to get some psychological support as to why they have been struggling with obesity in the first place. And if all you’re going to do is give them a drug to lose the kilos, you’re not actually addressing the cause.”

Yates says there are also concerns that weight-loss medication could contribute to eating disorders.

“We’ve come so far as a community on addressing the stigma of weight and shame,” she says. “This medication does give people who are struggling with that a fairly powerful and toxic tool.”

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