A small but growing proportion of children under the age of 12 with obesity are being prescribed GLP-1 drugs to help them lose weight. There are signs that this successfully treats obesity, but there are also concerns about the drugs’ long-term effects. So, is this trend likely to continue, and should it?

Earlier this month, a study led by Babak Orandi at New York University found that 9.3 per cent of children in the US aged 8 to 11 with obesity but without diabetes are being prescribed GLP-1 medications like semaglutide (Wegovy) and tirzepatide (Zepbound) – up from 0.03 per cent in 2019.

The following week, Novo Nordisk, the maker of Wegovy, reported that 40 per cent of children aged 6 to 12 with severe obesity who received weekly injections of the drug during a 68-week clinical trial were no longer classified as having obesity.

GLP-1 drugs are only approved for use in people aged 12 and older in the UK, US and Australia, but they are sometimes prescribed off-label to children as young as 8 in the US, in line with guidance from the American Academy of Pediatrics.

Orandi found that those under 12 were more likely to receive these off-label prescriptions if they had severe obesity or related complications, such as pre-diabetes, sleep apnoea, high blood pressure or high cholesterol. Their families also tended to be richer. “[The treatment] can be hundreds of dollars a month,” he says.  

The number of young children in the US taking GLP-1 drugs will probably continue to climb because “if you look at the numbers, there are still a lot of kids with complications of obesity who are not getting them”, says Orandi.

There is a growing view among healthcare practitioners that withholding GLP-1 drugs from these children might be riskier than prescribing them, he says. This is because childhood obesity is associated with depression and low self-esteem, and it increases the risk of conditions such as heart disease, type 2 diabetes and liver disease later on. Severe obesity before the age of 4 has been estimated to cut life expectancy by up to 42 years.

“[GLP-1 drugs] are changing the landscape rapidly and I think young people with obesity now have hope that something might change for them and their health trajectory,” says Danielle Longmore at the Murdoch Children’s Research Institute in Melbourne.

Guidance on healthy eating and physical activity is recommended as the first-line treatment for obesity, but it doesn’t work for some children, says Longmore. “Obesity is a very complex, multifactorial condition with genetic and environmental components, and it’s very challenging for a lot of young people and their families to make change,” she says.

At this stage, we don’t know what the long-term effects might be of children taking GLP-1 drugs while their bodies are growing or going through puberty. A recent study found that the medications increased the risk of children developing iron and other nutrient deficiencies due to their reduced food intake.

“We know from other health conditions that if you’re not gaining weight or if you’re not well-nourished as a child, it can stall growth and delay puberty,” says Longmore. “I worry about these kids who are losing lots of weight and muscle – what’s going to be the effect on their strength and their bones when they’re older? Could there be implications for pregnancy and menopause later on? We haven’t really thought that far ahead.”

Nevertheless, Longmore believes there is a case to be made for countries like the UK and Australia to extend GLP-1 drug access to children under the age of 12 if their obesity is severe. “I think that would need to be a very considered decision, but there might be some young children whose health risks are so great at the moment that it’s probably worth giving these medications a try,” she says.

“It’s still an open question as to what the effects are of GLP-1 drugs on children’s development and we don’t really know what that looks like yet, but we do know what it looks like for kids with obesity, and the risk of not treating is real,” says Orandi.  

The side effects of GLP-1 medications are the same in children as in adults and include nausea, diarrhoea and sometimes “horrible burps”, says Longmore. But children usually don’t mind the weekly injections, she says. “It’s not particularly painful, it’s just under the skin with a very fine needle.”

One problem is that children, like adults, often regain weight when they stop taking GLP-1 drugs, which raises the question of whether they will have to be on them for life. To prevent this weight regain, it is important to try to tackle the reasons the child developed obesity in the first place, ideally by working with dieticians, psychologists and exercise physiologists, says Longmore.

“I would caution that these drugs are not going to be the easy way out for most young people with obesity, and it’s important not to lose sight of addressing the underlying drivers of obesity,” she says.