Early trial shows promise for new hormone treatment in FSHD

22 September 2025

A potential new treatment for facioscapulohumeral muscular dystrophy (FSHD) has shown encouraging results in an early clinical trial. The treatment uses two hormones: testosterone, which helps build muscle, and a lab-made version of human growth hormone, which helps cells grow and repair.

Together, these hormones may help improve muscle strength and breathing in people with FSHD.

In the trial, 20 men with FSHD took the treatment for six months. It was found to be safe. After six months, for the 19 men who completed the study:

• Their lean body mass (muscle and other non-fat tissue) increased by 2.2 kg
• Their fat mass went down by 1.3 kg
• They could walk on average, 37.3 metres further in six minutes
• Their muscle strength improved
• Their score on a test called the FSHD-COM, which measures how well someone can move and use their muscles, improved by 2.4 points

These results are promising, but they need to be confirmed in a larger trial. This next trial will include more people and compare the hormone treatment with a dummy drug (called a placebo). This helps researchers check that the improvements are really due to the treatment and not other factors.