We use essential cookies (authentication, your saved goals/stack) by default. With your permission we'll also enable privacy-respecting analytics (Vercel Web Analytics, anonymous load-time metrics) and error-replay diagnostics (Sentry — DOM snapshots only when an error fires) so we can fix bugs faster. Learn more about cookies

Fst1.8

Follistatin Research

Mostly mechanism / observationalLimited safety

6 peer-reviewed studies

What the evidence says

Mostly mechanism / observational

Most Follistatin studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.

Most evidence is from mixed-quality studies published 2001–2024.

Based on 6 studies

Confidence

Low

By outcome

Lean body mass & muscle growth
Mostly mechanism / observational4 studies
Therapeutic & clinical
Mostly mechanism / observational4 studies
Muscle strength & power
Too few graded studies1 study
Safety profile
Too few graded studies1 study

Steady research

1 study in the last 5 years

200120122024

1Animal2001

Independent transgenic mouse lines for each construct exhibited dramatic increases in muscle mass comparable to those seen in myostatin knockout mice.

Lee SJ, McPherron AC. · Proc Natl Acad Sci U S A (2001)

Mechanistic foundation: purified myostatin binds the activin type II receptors ActRIIB (and, less, ActRIIA), and this binding is inhibited by follistatin and the myostatin propeptide
Transgenic mice expressing follistatin or a dominant-negative ActRIIB in muscle showed dramatic hypertrophy comparable to myostatin-knockout mice
Establishes ActRIIB as the receptor that ACE-031's soluble decoy is designed to mimic and block — the scientific basis for the whole approach

View source

2Animal2010

Administration of a recombinant adeno-associated virus serotype 8 vector encoding follistatin, an inhibitor of myostatin, increased muscle mass and strength but only in Pompe mice that were treated before 10 months of age.

Foley JW, Bercury SD, Finn P, Cheng SH, Scheule RK, Ziegler RJ. · Mol Ther (2010)

AAV8-follistatin gene therapy in a Pompe-disease mouse model of progressive muscle dysfunction
Increased muscle mass and grip strength — but only when treated before 10 months of age, highlighting that timing matters
Maximal strength gains required clearing muscle glycogen with concomitant GAA enzyme therapy; follistatin alone failed to improve rotarod performance

View source

3Animal2020

AAV-mediated FST delivery exhibited decreased obesity-induced inflammatory adipokines and cytokines systemically and in the joint synovial fluid.

Tang R, Harasymowicz NS, Wu CL, Collins KH, Choi YR, Oswald SJ, Guilak F. · Sci Adv (2020)

AAV9-follistatin gene therapy in high-fat-diet obese mice, testing effects beyond muscle
Decreased obesity-induced inflammatory adipokines and cytokines, systemically and in joint synovial fluid
Mice were protected from post-traumatic osteoarthritis and joint-injury-induced bone remodeling, regardless of diet

View source

4Open-Label2015

AAV1.CMV.FS344 was delivered to six BMD patients by direct bilateral intramuscular quadriceps injections... Patients 01 and 02 improved 58 meters (m) and 125 m, respectively.

Mendell JR, Sahenk Z, Malik V, Gomez AM, Flanigan KM, Lowes LP, Alfano LN, Berry K, Meadows E, Lewis S, Braun L, Shontz K, Rouhana M, Clark KR, Rosales XQ, Al-Zaidy S, Govoni A, Rodino-Klapac LR, Hogan MJ, Kaspar BK. · Mol Ther (2015)

The closest human evidence — but it is GENE therapy, not injectable peptide: AAV1.CMV.FS344 (the follistatin gene) injected directly into the quadriceps of six men with Becker muscular dystrophy
Four of six patients improved on the 6-minute-walk test (29-125 m); two showed no change
Biopsies showed reduced endomysial fibrosis, reduced central nucleation, more normal fibre-size distribution and muscle hypertrophy, especially at the higher dose; no adverse effects reported

View source

5Open-Label2017

Performance, annualized to a median 1-year change, improved +56.0 m/year for treated subjects compared to a decline of -25.8 m/year (p = 0.01) in untreated subjects.

Mendell JR, Sahenk Z, Al-Zaidy S, Rodino-Klapac LR, Lowes LP, Alfano LN, Berry K, Miller N, Yalvac M, Dvorchik I, Moore-Clingenpeel M, Flanigan KM, Church K, Shontz K, Curry C, Lewis S, McColly M, Hogan MJ, Kaspar BK. · Mol Ther (2017)

Second human follistatin GENE-therapy trial: rAAV1.CMV.huFS344 delivered to the quadriceps of six patients with sporadic inclusion-body myositis, with an exercise regimen
6-minute-walk improved +56.0 m/year in treated subjects versus -25.8 m/year in matched untreated subjects (p=0.01)
Four of six treated subjects improved 58-153 m; two were minimally improved; treatment effects included decreased fibrosis and improved regeneration

View source

6Review2024

These include myostatin inhibitors, selective androgen receptor modulators, ghrelin receptor agonists, mesenchymal stem cell therapy, and follistatin gene therapy.

Chen LK. · J Chin Med Assoc (2024)

Review of emerging pharmaceutical interventions for sarcopenia (age-related muscle loss)
Lists follistatin gene therapy among over 20 compounds in clinical development, alongside myostatin inhibitors and SARMs
Frames these as investigational — current management still rests on resistance exercise and adequate protein intake (≥1.2 g/kg/day)

View source

View in Research Library

Follistatin Research

Mostly mechanism / observational

Regulation of myostatin activity and muscle growth.

Evaluation of systemic follistatin as an adjuvant to stimulate muscle repair and improve motor function in Pompe mice.

Gene therapy for follistatin mitigates systemic metabolic inflammation and post-traumatic arthritis in high-fat diet-induced obesity.

A phase 1/2a follistatin gene therapy trial for becker muscular dystrophy.

Follistatin Gene Therapy for Sporadic Inclusion Body Myositis Improves Functional Outcomes.

Sarcopenia in the era of precision health: Toward personalized interventions for healthy longevity.