Ask the Doctor: What’s the deal with Ozempic?

“I’ve been hearing about Ozempic constantly, and the discourse surrounding it has been very confusing. Some say it’s a miracle weight loss drug, others say it’s incredibly dangerous, so I’m not quite sure what to believe. I’ve heard it can have a positive impact on cardiovascular health — is this true? If so, what are the benefits and dangers?”

Answer from Professor Mark Dayer, consultant cardiologist and the lead for heart failure at Mater Private Network. He has a strong interest in cardiovascular prevention.

Obesity is now considered to be a global public health challenge. It is growing in prevalence and is associated with poor health outcomes, including increased risks of heart failure, diabetes, stroke and death. Anything that can help tackle this is important.

Ozempic, the brand name of Semaglutide, seems to be everywhere. It’s made by a Danish drug company called Novo-Nordisk. The Danes are already the happiest nation, and the share price has skyrocketed, making some of them even happier. It was originally developed to treat type 2 diabetes. It’s a “GLP-1 receptor agonist” and stimulates insulin release, but it also has other effects. It is thought to promote weight loss by making people feel fuller. People typically lose about 5-10% of their weight or more, although not all do, and it can rebound when you stop taking the drug. This has made it popular in Hollywood, where thinness is everything, and people like Sharon Osbourne and Oprah Winfrey have openly admitted to using it.

There is good evidence that Semaglutide can have health benefits, too. Back in 2016, the first big pivotal trial in people with type 2 diabetes and who were overweight, who were also at high risk of heart disease or had heart disease already, was published. In the two years that the study lasted, there was no difference in the number of deaths, but those who had Semaglutide had fewer heart attacks and strokes, and fewer developed kidney problems. Blood sugar control was better, blood pressure was lower, and their weight fell significantly. However, more people had problems with their eyes (diabetic retinopathy), and many stopped taking the drug because of nausea and vomiting. (1)

In 2021, another big trial was published. This just looked at people who were overweight and who did not have diabetes. Those who took Semaglutide lost approximately 15% of their body weight after just over a year. The average weight loss was 15.3 kg in 68 weeks. Nausea and vomiting were again an issue. (2) In 2022, a similar study was done on adolescents between the ages of 12-18. Similar results were found. (3)

Most recently, Semaglutide has been trialled in patients with heart failure (a particular subtype of heart failure – those with a “normal ejection fraction”) and obesity. (4) This was a smaller trial. Weight loss was similar to the other studies. There were clear improvements in quality of life and exercise capacity. In this particular subset of patients with heart failure, improvements have been hard to come by, so the medical profession viewed this as a positive development.

Excitingly, other drugs are in the pipeline, which may be more effective than Semaglutide, as they act on other targets as well. Tirzepatide is one of the next in line.

But it’s not all been plain sailing. Firstly, weight tends to rebound after stopping the drug unless lifestyle has been changed too. Secondly, some have questioned whether the weight that is lost is all “good” weight; that is, people seem to lose muscle, too. This might be simply because you need less muscle to move a lighter body around, but there may be more to it than that. There have also been issues with the availability of Semaglutide, and some have objected to the drug being made available to the rich wanting to lose weight, whilst people with diabetes, who have been taking it for a while, can’t get hold of the drug.

Still, others have pointed out that it seems crazy that there are many people struggling to feed their families due to the cost of living crunch and outright famine in other countries, whilst others are spending money on drugs to help them lose weight.

Many have argued we should be investing in getting people’s diets and lifestyles sorted first and battling the prevalence of highly processed foods, which are often full of fat, sugar and salt, and many believe are part of the problem. What is clear is that Semaglutide, used carefully, can help reduce weight and improve the outlook and quality of life for some people. But some caution is needed, as the whole story has yet to be worked out.

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Incretin: A hormone produced in the GIT that regulates insulin secretion – GLP and GIP

GLP-1RA: Glucagon-like peptide-1 receptor agonist

GIP RA: Glucose-dependent insulinotropic polypeptide receptor agonist

GR A: Glucagon receptor agonist

GLP-1RA: Liraglutide Semaglutide

GLP-1RA + GIP RA: Tirzepatide

GLP-1 RA+: Under development – e.g. NN0090-2746

1. N Engl J Med 2016;375:1834-44. DOI: 10.1056/NEJMoa1607141

2. N Engl J Med 2021;384:989-1002. DOI: 10.1056/NEJMoa2032183

3. N Engl J Med 2022;387:2245-57. DOI: 10.1056/NEJMoa2208601

4. N Engl J Med 2023;389:1069-84. DOI: 10.1056/NEJMoa2306963