What Is Follistatin 344?
Follistatin is a single-chain glycoprotein produced by folliculostellate cells of the pituitary gland and by multiple peripheral tissues. It functions as a high-affinity binding protein for TGF-β superfamily members, most critically myostatin (GDF-8) and activin A. Follistatin 344 refers to the 344-amino-acid isoform, which is the predominant extracellular form found in muscle tissue.
Myostatin: The Muscle Growth Limiter
Myostatin is an endogenous negative regulator of skeletal muscle mass. Animals and humans with naturally occurring myostatin mutations exhibit dramatic muscle hyperplasia — documented in myostatin-null cattle, dogs, sheep, and even human infants. By binding myostatin with extraordinarily high affinity (Kd in the picomolar range), Follistatin 344 effectively neutralizes this growth inhibitory signal, removing the molecular brake on satellite cell activation and myofiber hypertrophy.
Research Applications
Gene therapy studies using Follistatin 344 vectors have produced striking muscle mass increases in primate models. Clinical trials in Becker Muscular Dystrophy patients have shown favorable safety profiles and functional improvements. Recombinant Follistatin 344 protein research focuses on cachexia, sarcopenia, and age-related muscle loss as therapeutic targets.
Bone and Metabolic Effects
Beyond muscle, Follistatin 344 has demonstrated effects on bone mineral density (by inhibiting activin-mediated bone resorption) and metabolic function, including improved glucose homeostasis in animal models of obesity and diabetes.
Quick Reference
Member reference tables summarize the compound's research parameters.
Research Indications
Research Protocols
As reported in cited literature and research-community logs (see Research Citations below), not a personal dosing recommendation.
This member section describes parameters reported in the research literature.
Peptide Interactions
This member section summarizes reported compound interactions and evidence limitations.
Reported Research Time Points
This member section summarizes reported research time points.
Safety Notes
Included for harm-reduction awareness only, in the event this compound is encountered outside its labeled research use. Inclusion here does not imply RUO Codes endorses, recommends, or instructs human use.
This member section discusses research safety considerations and uncertainties.
Quality Indicators
Research Citations
- Follistatin gene delivery enhances muscle growth and strength in nonhuman primates
Kota, J., Handy, C.R., Haidet, A.M., Montgomery, C.L., Eagle, A., Rodino-Klapac, L.R., et al., 2009, Science Translational Medicine - A Phase 1/2a Follistatin Gene Therapy Trial for Becker Muscular Dystrophy
Mendell, J.R., Sahenk, Z., Malik, V., Campbell, K.J., et al., 2015, Molecular Therapy - Long-term enhancement of skeletal muscle mass and strength by single gene administration of myostatin inhibitors
Haidet, A.M., Rber, L., Montgomery, C.L., et al., 2008, Proceedings of the National Academy of Sciences - Follistatin induces muscle hypertrophy through satellite cell proliferation and inhibition of both myostatin and activin
Gilson, H., Schakman, O., Kalista, S., Lause, P., Tsuchida, K., Thissen, J.P., 2009, American Journal of Physiology - Endocrinology and Metabolism - Inhibition of myostatin with emphasis on follistatin as a therapy for muscle disease
Rodino-Klapac, L.R., Haidet, A.M., Kota, J., Handy, C., Kaspar, B.K., Mendell, J.R., 2009, Neuromuscular Disorders - An engineered human follistatin variant: insights into the pharmacokinetic and pharmocodynamic relationships
Datta-Mannan, A., Yaden, B., Engstrom, M., et al., 2013, Journal of Pharmaceutical Sciences - Central serous chorioretinopathy associated with high-dose follistatin-344: a retrospective case series
Dağ U, Çağlayan M, Öncül H, 2020, Int Ophthalmol