Follistatin

Follistatin (FS344 / FS315)

Description:
Follistatin is a naturally occurring glycoprotein peptide that functions as a potent myostatin inhibitor, promoting muscle growth, regeneration, and cellular differentiation. It binds to and neutralizes myostatin (GDF-8) and other members of the TGF-β superfamily, removing the natural inhibition on muscle cell development. The FS344 isoform (precursor of FS315) is the most biologically active and extensively researched variant, known for its role in muscle hypertrophy, fertility regulation, and tissue repair.

Key Benefits:

• Inhibits myostatin and activin signaling

• Promotes lean muscle growth and tissue regeneration

• Enhances strength and physical recovery

• Supports research in muscle wasting and sarcopenia

• May assist in metabolic and endocrine regulation

Mechanism of Action:
Follistatin binds directly to myostatin and activin A, preventing them from attaching to their receptor (ActRIIB) on muscle cells. This blockade removes inhibitory feedback on muscle protein synthesis and satellite cell activation, resulting in enhanced muscle fiber growth and regeneration. Additionally, Follistatin has been shown to regulate cellular differentiation, inflammation, and reproductive signaling, making it a versatile peptide in muscle biology and regenerative medicine research.

Molecular Formula: C28H47N9O7 (core peptide domain; full-length glycoprotein form varies)
Molecular Weight: ~38–44 kDa (depending on isoform and glycosylation)
Isoforms: FS288, FS315, FS344 (precursor form)
Purity: ≥98% (HPLC)
Form: Lyophilized peptide powder for reconstitution

Storage:
Store at −20°C. Protect from heat, light, and moisture. Once reconstituted, refrigerate (2–8°C) and use within 30 days. Avoid repeated freeze–thaw cycles.

Disclaimer:
For laboratory research use only. Not for human consumption.