Weight Loss Injection for Children Cleared Its First Big Trial

The drug behind Wegovy and Ozempic has now been tested in a late-stage trial on children starting at age six. The result landed this week and is being reported everywhere with a headline number worth reading slowly, because a weight loss injection for children that young raises questions the announcement does not yet answer.

Novo Nordisk announced on Monday that in a phase 3 trial called STEP Young, 40.4 percent of children aged six to under 12 treated with semaglutide were no longer classified as having obesity after 68 weeks, against none of those on placebo. The company said the trial met its primary goal of showing greater reduction in body mass index than placebo.

What did the semaglutide trial in children actually measure?

The semaglutide trial in children was small by drug trial standards, with 165 participants across several countries, all of whom had obesity, and more than 85 percent in the more severe categories at the start. One detail gets lost in most coverage. Every child in the trial, placebo group included, was on a lifestyle program running throughout, built on a reduced-calorie eating plan and increased physical activity. The drug was tested as an addition to that care rather than a replacement for it, and Novo's chief scientific officer, Martin Holst Lange, framed the finding in exactly those terms.

Which safety data is still missing?

What came out on Monday was a company press release with topline results. Novo said the overall safety and tolerability picture was consistent with its adult and adolescent trials, but the detailed figures were not included, and the safety data still missing is the part that will decide how this lands. Full results are scheduled for ObesityWeek in Washington in mid-November. Independent commentators have already flagged the open questions, and they are the obvious ones for this age group. How durable the effect is, what happens when treatment stops, and what the drug does during growth and puberty are all unresolved until the detailed data is published.

Where does Health Canada approval stand right now?

Semaglutide is not approved anywhere for weight management in children under 12, and that includes Canada. Health Canada approval currently covers Wegovy for adolescents aged 12 to under 18 with obesity, and in late June the department authorized the first generic semaglutide injection for weight management, also for patients 12 and over. A trial result does not change an approval, and a submission for a younger age group would be a separate process on its own timeline. A weight loss injection for children under 12 is not something a Canadian prescriber can currently offer on label.

For teenagers, Canadian guidance has already moved. In April 2025 the Canadian Medical Association Journal published the first new Canadian guideline on managing obesity in children in nearly two decades, developed with the health charity Obesity Canada. It carries 10 recommendations, one of which supports considering GLP-1 receptor agonists, the drug class semaglutide belongs to, in combination with behavioural and psychological support, and specifically for children aged 12 and older. The guideline is explicit that effectiveness and safety below that age had not been evaluated. Sanjeev Sockalingam, scientific director of Obesity Canada, has emphasized shifting the focus for young people away from weight alone and toward quality of life and mental health, which is the framing the guideline itself uses.

How much off-label prescribing in children already happens?

More than most people realize, and this is why a trial in this age band matters regardless of what you make of the result. A study published on 4 September in the journal Pediatrics found that GLP-1 prescribing among American children aged eight to 11 with obesity rose 310-fold between 2019 and 2026. The context matters as much as the multiple. Across more than 3.5 million children in that cohort, only 0.6 percent ever received a prescription, about 20,000 children in total, and prescribing concentrated among those with the most severe presentations and related conditions. Off-label prescribing in children has been running ahead of the evidence, but from a very small base. That gap is why a controlled trial of a weight-loss injection for children this young matters, whatever it eventually shows.

Should you be talking to a doctor about a child's weight?

If you are a parent reading a headline about six-year-olds and a weight-loss injection, the useful takeaway is narrow. This is one trial, in a small group of children with a specific and severe medical presentation, with the detailed safety data still pending, and the drug is not available for that age group in Canada. Talking to a doctor about a child's weight starts somewhere else entirely. Canadian guidance treats this as a chronic medical condition and is clear that care begins with a proper assessment rather than a prescription, one that looks at overall health, quality of life and mental health rather than a number on a scale. The 2025 guideline puts nutrition counselling, physical activity support and behavioural care at the centre, with medication as one option a clinician may consider in specific circumstances.

It is also a conversation to have with someone who knows your child rather than one to settle from a news story or a social feed. Plenty of what shapes a child's health sits outside any prescription, from the one in three Ontario children living in a food-insecure home to which age group is actually falling short on protein, and mental health belongs in the same conversation given what the research says about children who play alone.

Questions parents are asking

Is this injection approved for children in Canada?

Not for children under 12. Health Canada has authorized semaglutide for weight management in adolescents aged 12 to under 18, and a generic version carries the same age limit. The STEP Young result is a trial finding, not an approval, and any submission covering younger children would be assessed separately with its own timeline.

What did the trial find?

In 165 children aged six to under 12 with obesity, 40.4 percent of those given semaglutide were no longer classified as having obesity at 68 weeks, compared with none on placebo. Both groups followed a reduced-calorie eating plan and increased physical activity throughout, so the drug was tested as an addition to that care.

What is still unknown for this age group?

The detailed safety and tolerability data have not been released and are due at a conference in November. The open questions include what the drug does during growth and puberty, how durable the effect is, and what happens after treatment stops. Canadian guidance notes that effectiveness and safety in children under 12 had not been evaluated.

Where should a worried parent start?

With an assessment from a clinician who knows your child. Canadian guidance puts nutrition counselling, physical activity support and behavioural care at the centre of treatment, and frames success around overall health, quality of life and mental health rather than a number. Medication is one option a clinician may raise in specific circumstances, not the starting point.

Worth noting for context, adolescent wellbeing has moved in more than one direction this year, and the Ontario survey showing teen mental health improving for the first time in years is a reminder that these conversations rarely sit in one lane. If you do book an appointment, bringing your questions written down in advance makes a short visit go considerably further.

This article is general information and not medical advice. If you are having a medical emergency, call 911. For anything non-urgent, speak with a doctor or another qualified health professional about your own situation.

If you want your child assessed properly, or you have questions about what care actually looks like in Canada, you can compare dietitians near you and see current availability on Medimap, or browse the Medimap Health Hub for more on children's health.