What Gene Therapy Could Mean for the Future of Muscle Health, with Dr Sanjeev Goel, MD

Muscle loss is often treated as an inevitable part of ageing, but researchers are increasingly examining whether some of the biological mechanisms behind declining muscle mass can be influenced.

One area attracting attention is the relationship between myostatin and follistatin, two proteins involved in regulating muscle growth. As researchers learn more about how these pathways work, they are also exploring new possibilities for supporting muscle health and physical function later in life.

Dr Sanjeev Goel, MD, Founder and CEO of Peak Human, is exploring this area through an investigational approach involving gene therapy designed to increase the body's production of follistatin.

Rather than relying on repeated injections or daily supplements, the concept is to provide cells with genetic instructions that could encourage sustained follistatin expression over an extended period.

This approach represents an emerging area of research that could offer scientists new ways to study and potentially influence the biological processes involved in muscle maintenance.

Understanding the Myostatin 'Brake'

Myostatin is a naturally occurring protein that acts as a regulator of skeletal muscle development. In simple terms, it helps prevent excessive muscle growth. Follistatin, meanwhile, can bind to myostatin and other members of the transforming growth factor beta (TGF-β) family, potentially reducing their activity.

This biological relationship has made the pathway an area of interest in research into muscle wasting, ageing, metabolic health, and physical performance.

The idea is not that myostatin is inherently harmful. Its regulatory role is part of normal human biology. The question researchers are investigating is whether modifying this pathway could eventually help preserve muscle tissue or physical function in specific circumstances.

That question becomes particularly relevant as physical inactivity increases with age. According to the World Health Organization, 31% of adults worldwide, approximately 1.8 billion people, did not meet recommended levels of physical activity in 2022. If current trends continue, that figure is projected to reach 35% by 2030.

The numbers highlight an important distinction: maintaining muscle is not simply a question of appearance. Regular physical activity remains one of the established foundations of healthy ageing.

Why Muscle Matters Beyond Appearance

Muscle contributes to much more than strength or physique. Skeletal muscle plays an important role in movement, glucose regulation, balance, and physical independence.

Research also suggests that muscle strength can provide a more meaningful picture of physical health than size alone. In a U.S. analysis of adults aged 50 to 80, 25.6% met the study's sarcopenia criterion based on grip strength, compared with 15.6% using an appendicular lean-mass measure and 13.8% using gait speed.

The differences between these measures illustrate why muscle health is complex. Having more lean mass does not necessarily mean having greater functional strength, and measurements can vary depending on how muscle health is defined.

For that reason, approaches to preserving muscle increasingly focus on function as well as composition.

How Follistatin Gene Therapy Is Intended to Work

The approach described by Dr Goel uses a gene-delivery system such as an adeno-associated virus (AAV) vector or plasmid-based technology to deliver genetic instructions associated with follistatin production.

The underlying concept is different from taking a peptide or hormone repeatedly. Instead, the treatment aims to encourage cells to produce the relevant protein themselves for an extended period.

In theory, increased follistatin could reduce myostatin activity and influence the signals that regulate muscle growth. Researchers can then evaluate changes through measurements such as muscle mass, strength, body composition, and other physiological markers.

Although rigorous clinical studies of follistatin gene therapy remain limited, preliminary observational data reported by companies such as BioViva and Minicircle have shown potentially promising findings in humans.

These early observations have contributed to interest in the approach and provide a basis for further investigation, but they do not establish safety or effectiveness.

Further research will be needed to determine whether these early findings can be consistently replicated and to better understand factors such as dosing, delivery, durability, safety, and long-term effects.

The performance of a gene therapy can depend on the delivery system, dose, tissue targeting, individual biology, and many other variables. For that reason, claims about specific outcomes or how long an effect may last should be treated cautiously until supported by well-designed clinical studies.

What Could Researchers Learn?

One of the more interesting questions in this field is how changes in the myostatin-follistatin pathway might translate into measurable changes in muscle function and overall physiology.

Rather than looking only at whether someone gains lean mass, researchers can examine a broader range of outcomes, including strength, body composition, functional capacity, and metabolic markers. This may help clarify whether changes in muscle tissue are accompanied by meaningful improvements in the body's performance.

The distinction matters because muscle size alone does not necessarily reflect muscle quality or physical capability. Factors such as cardiovascular fitness, nutrition, insulin sensitivity, and activity levels can also influence health outcomes.

Studying these measures together could give researchers a more complete understanding of how interventions targeting muscle biology affect the body over time. It may also help identify which outcomes are most meaningful when evaluating new approaches to muscle preservation.

A Developing Area of Medicine

Gene therapy is creating new opportunities to better understand the biological pathways involved in muscle maintenance and growth.

Research into follistatin and myostatin is particularly encouraging because it is helping scientists better understand the body's natural mechanisms for regulating muscle, while potentially opening new avenues for supporting muscle health, physical function, and healthier ageing.

The broader significance extends beyond muscle size or physical appearance. Strength, mobility, and metabolic health all contribute to how well people move, recover, and remain independent throughout life.

Established habits such as resistance training, adequate nutrition, cardiovascular activity, quality sleep, and regular medical monitoring remain important foundations, while emerging research may eventually expand the range of tools available for supporting muscle health as people age.