Semaglutide injections – effective and safe?

Anti-diabetic drugs like semaglutide injections are getting lots of headlines – but how effective and safe are they for weight loss? And what are the side effects of semaglutide? DR REGINALD LIEW, Senior Consultant Cardiologist at The Harley Street Heart and Vascular Centre, shares his opinions.

Obesity is a major risk factor for heart disease. Carrying excess weight can put extra stress on your heart, increasing the risk of developing coronary artery blockages, heart attack, diabetes, high blood pressure and heart rhythm problems. Many people who are overweight find it difficult to lose weight, despite lifestyle and dietary changes – and they’re turning to alternative options.

In recent years, semaglutide injections and other similar anti-diabetic drugs have taken the world by storm and been touted as “wonder drugs” for weight loss. Even well-known figures such as Elon Musk and Oprah Winfrey have publicly admitted to using them. But do they work? And are they safe to take?

About semaglutide injections

Semaglutide injections were originally developed as an anti-diabetic drug. Medical studies have shown it can also lower the risk of heart attack and stroke in people with diabetes and cardiac risk factors. Although not FDA-approved for weight loss, semaglutide injections are increasingly being used off-label in people without diabetes to help them lose weight.

A higher-dose version of these semaglutide injections has been approved for weight loss in certain adults and adolescents aged 12 and older. It can be used by people without diabetes to help them lose weight but should only be given under medical supervision to those who are overweight with at least one weight-related comorbidity, such as high blood pressure, diabetes or high cholesterol.

How are they taken and how do they work?

These anti-diabetic drugs are once-weekly injections that contain the same active ingredient, semaglutide. Semaglutide works by mimicking the actions of a hormone called glucagon-like peptide-1 (GLP-1) that is naturally released in the gastrointestinal tract in response to eating. These GLP-1 analogues work by slowing down gastric emptying and having effects on the brain to reduce appetite and increase the sensation of feeling full.

Semaglutide injections are intended to be taken long-term. If you start taking them and then stop without taking any other steps to maintain the lower weight, it’s possible for your weight to increase again. The drugs can only be provided by a doctor or obtained through a prescription from a pharmacist. Semaglutide injections seem to be effective in reducing weight by about 10 to 20 percent in a large proportion of people.

What are the potential problems with semaglutide injections?

Despite the medical benefits of improved diabetic control and reduced cardiac risk, semaglutide injections can also result in side effects. So the decision to start them should be carefully made with a medical specialist. Potential problems include:

• Possible semaglutide side effects such as nausea, diarrhoea, stomach pain, bloating, constipation, pain or redness at the injection site.
• Risk of thyroid/endocrine tumours and cancers, particularly in those with a family history of endocrine tumours.
• Rare risk of pancreatitis.
• Decrease in muscle mass (a condition called sarcopenia) and bone density.
• Rebound weight gain after stopping the drug.
• Potential long-term effects (currently unknown as the drugs are relatively new).

Final word

Obesity is a major health problem, but GLP-1 analogues like semaglutide injections can have a role to play with weight loss. However, semaglutide injections may have side effects and should be used with caution under medical supervision. If you’re overweight and have cardiac risk factors, consult your doctor or cardiologist to check for any underlying heart problems. You can also discuss the best management options with them, which may include trying one of these GLP-1 analogues.

The Harley Street Heart and Vascular Centre
#02-38/41 Annexe Block, Gleneagles Hospital, 6A Napier Road
6472 3703 | harleystreet.sg

This article on anti-diabetic drugs, semaglutide injections for weight loss and semaglutide side effects first appeared in the March 2025 edition of Expat Living. You can purchase the latest issue or subscribe so you never miss a copy!

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