Follistatin gene therapy effects on epigenetic clocks: preprint

Researchers gave mice gene therapy, a treatment that adds genetic instructions to cells, to produce more follistatin, a protein involved in muscle growth and repair. They then used epigenetic clocks, estimates of biological age based on DNA methylation, which are chemical tags attached to DNA. Some clock results moved in a younger direction, but other measures did not show a clear improvement. The study was in mice and was released as a preprint, meaning it had not yet completed full scientific review.

What this means for you: This does not show that follistatin gene therapy makes people younger or healthier. You can ignore commercial claims based on this study, because mouse results and indirect age estimates do not establish human benefits or safety.