Weight-loss drugs for first-graders? Eli Lilly is testing Mounjaro shots on kids as young as 6

• The makers of Ozempic and Mounjaro are both trying out GLP-1 shots on kids with obesity.
• GLP-1 hormone-mimicking drugs are generally considered safe for most adults.

The pharmaceutical giants behind Ozempic and Mounjaro are zeroing in on their next potential market for weight loss injections: first graders.

Both Novo Nordisk and Eli Lilly are working on pediatric clinical trials for their new class of injectable GLP-1 medications —the blockbuster insulin-regulating and appetite-reducing drugs for diabetes which have, in recent years, also become weight loss aids.

Eli Lilly has confirmed to Insider that the company is testing out Mounjaro on kids with obesity who are as young as six years old, as Bloomberg first reported on Friday. This is a small, Phase 1 trial — studying 30 patients for 13 weeks — that is much smaller and more early-stage than the Phase 3 trials of Mounjaro that are ongoing in teens.

Adults on Mounjaro without diabetes have, on average, lost more than a quarter of their body weight (27%) on the same drug, while adults with diabetes have lost 15% of their size on Mounjaro. Doctors in the field of obesity and endocrinology have been overwhelmingly stunned, shocked, and thrilled by these results, which are almost on par with bariatric surgery, in terms of the weight loss.

"These patients need new clothes, with a decrease in waist circumference of over five inches," Dr. W Timothy Garvey, a senior scientist at the University of Alabama said earlier this year, announcing some Mounjaro research results at the American Diabetes Association conference.

While GLP-1 drugs are generally considered safe for most adults, there are dangerous, rare side effects, including cases of stomach paralysis that may not be reversible. Scientists don't really know yet how the hormone-mimicking medications might work in kids' developing bodies, which is why they're conducting these trials.

Ozempic-maker Novo Nordisk has already been trying a low-dose, daily injectable GLP-1 on kids as young as 6

Novo Nordisk has, for about two years, been administering a GLP-1 drug called Saxenda (which contains the drug liraglutide) to kids with obesity between the ages of 6 and 12 years old, in a clinical trial with fewer than 100 participants.

Liraglutide is a once-daily shot, and was a lower dose, lower-powered precursor to the once-weekly semaglutide injections that millions of Americans now take — medication that's branded as Ozempic for diabetes, and Wegovy for weight loss.

In addition to handing out Saxenda to kids, Novo Nordisk's pediatric trial has included discussions with the young patients about "healthy food choices" and "how they can be more physically active," according to details posted on ClinicalTrials.gov.

GLP-1 drugs mimic a hormone that humans produce naturally when we eat food, and are generally considered safe, though they do come with some uncomfortable side effects, especially early-on, which may include diarrhea, nausea, vomiting, and stomach pain.

In rare, but serious cases, the way GLP-1 medications slow down people's guts has resulted in serious paralysis. And, there have also been reports of suicidal thoughts in some people using GLP-1 drugs, which prompted the European Medicines Agency to take a closer look at 150 cases in July.