The drug will be marketed in the UK under the Wegovy brand name, the same as drug Ozempic, which has recently made headlines because of its popularity as a weight-loss aid used by celebrities.
But while these drugs have been shown to significantly reduce weight in overweight or obese patients in clinical trials, there's still a lot we don't know — including its effect on people who aren't overweight but are just trying to lose a few pounds .
Wegovy and Ozempic are brand names for the drug semaglutide. Semaglutide belongs to a class of drugs called GLP-1 receptor agonists, which mimic the naturally occurring hormone glucagon-like peptide-1 (or GLP-1 for short). GLP-1 is one of many hormones released by our gut after we eat.
Once released, GLP-1 does two very important things. First, it stimulates the pancreas to release insulin (the hormone responsible for regulating blood sugar levels). It also works on the brain by turning off hunger signals. This is where the anti-obesity effects of semaglutide stand out the most.
Weight control is thought to be around a “set point” – your default weight. This set point varies from person to person and is largely determined by an individual's genetic makeup. For some people, this set point is within the “normal” body mass index (BMI) range, but for others it may be within the overweight or obese BMI range.
If a person loses weight, the brain increases weight by increasing hunger and reducing energy expenditure (the calories the body burns throughout the day). This in turn has the effect of raising the weight to the body's set point.
Semaglutide basically turns off these functions. Thus, even with weight loss, these hunger pangs are suppressed—thus preventing weight regain.
significant weight loss
Semaglutide was originally used to control blood sugar in people with diabetes. But in 2021, a large clinical trial showed that the drug might help reduce weight if given in higher doses.
The study of 1,961 obese adults found that 86 percent of patients who received weekly semaglutide injections in combination with a low-calorie diet and daily exercise lost at least 5 percent of their body weight after 68 weeks. About 32 percent lost up to 20 percent of their body weight.
In contrast, only 32 percent of those who received a placebo drug combined with diet and exercise lost 5 percent of their body weight. Only about 2 percent of people who received the placebo lost 20 percent of their body weight.
On the face of it, these figures are impressive — and indeed compared to currently available weight loss drugs and programs. But there are some caveats.
First, all trial participants received individual counseling every four weeks to help them stick to a strict diet and exercise regime (eating 500 fewer calories per day and exercising 150 minutes per week).
Many people don't have access to this kind of support in the real world, so it's hard to know how many participants would stick with the changes — and whether semaglutide would have had such a dramatic effect without this level of intervention.
Participants attend monthly counseling sessions to help them adhere to lifestyle changes.
African Studio/Shutterstock
Second, semaglutide is not without side effects. Nausea, vomiting, diarrhea, and constipation were reported by 20-45% of participants. These symptoms were usually temporary, and only 7% of participants treated with semaglutide left the study as a result.
But even more concerning was the significant increase in the number of participants who took semaglutide who developed more serious health problems. Nearly 2 percent of the participants developed gallstones (three times the number in the placebo group), while a small number developed pancreas inflammation.
While the number of participants who developed these potentially life-threatening conditions was small, this could be a problem if the drugs were to be made more widely available.
weight recovery
Semaglutide is for temporary use only to help with weight loss. So what happens when people stop taking it?
A follow-up study of 232 participants in the original clinical trial showed that all regained nearly all of the weight lost within a year of stopping the drug. What's more, the drops in blood pressure, blood sugar, and cholesterol seen at the end of the initial trial all returned to pre-trial levels.
All of this points to the need for caution with these types of drugs. Weight loss is difficult, and a single “wonder drug” is unlikely to undo the many physiological changes associated with obesity and weight loss.
We should also be cautious about these drugs, given that they need to be taken continuously to maintain any weight lost, and we don't yet know what their long-term effects will be.
More drug compounds that mimic gut hormones are in development, many of which are more effective at reducing weight than semaglutide. The future looks bright for weight loss therapies, but ultimately, dietary and lifestyle changes always need to be an important part of any weight loss attempt. But semaglutide may very well be the jumpstarter many people need on their weight loss journey.
Simon Cork, Senior Lecturer in Physiology, Anglia Ruskin University
This article is republished from The Conversation under a Creative Commons license. Read the original text.
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