A new study has shed light on a groundbreaking innovation in the fight against obesity: a revolutionary new drug called apitegromab,which has been shown to significantly reduce the risk of muscle loss for patients on weight loss medications.

The $30 million toe in the water

The research , led by experts from AdventHealth Translational Research Institute in the US, analyzed data from 102 adults taking weekly jab Mounjaro, also known as tirzepatide. Patients can lose up to a fifth of their body weight in a little over a year.

Half of the group were also given apitegromab,with the other half given a placebo, or dummy drug. The study's findings suggest that apitegromab may improve the composition of weight loss by preserving lean mass while maintaining similar overall weight reduction.

Why 4,000 unsold units became the prize

Previous studies have shown that one third of the weight lost by people using the injections such as Wegovy and Mounjaro comes from muscle and bone, instead of fat. The latest study analyzed data from 102 adults taking weekly jab Mounjaro ,also known as tirzepatide.

People who took apitegromab alongside tirzepatide lost significantly less lean mass compared to those who were taking tirzepatide with a placebo. This is despite the two groups seeing similar overall weight loss.

What auditors flagged in the May filing

NHS spending on blockbuster weight loss jab soared four-fold in a year to over half a billion pounds with the bill now higher than any other drug. Medics in England issued 3.1million scripts for the drug in 2025/26 at a cost of £574million.

This is more than the NHS has ever spent on a single medicine in a single year, according to records dating back 20 years.

Who is the unnamed buyer?

While private prescriptions continue to boom with an estimated two and half million buying the injections, the study's findings suggest that apitegromab may improve the composition of weight loss by preserving lean mass while maintaining similar overall weight reduction.

Researchers, led by experts from AdventHealth Translational Research Institute in the US, found lean mass accounted for 14.6 per cent of total weight loss in the apitegromab group compared with 30.2 per cent among those who took the placebo, according to the phase 2 study, which has been published in the journal Nature Medicine .

Preserving lean mass: a new frontier in weight loss research

Strategies that help preserve lean mass while maintaining the benefits of weight reduction are of considerable interest, but whether they improve longer-term health outcomes remains to be established.

Preserving lean mass is biologically plausible and potentially beneficial,but larger and longer studies will be needed to determine whether these changes translate into meaningful improvements in strength ,physical function, quality of life, or long-term health outcomes.