Understand the source comparison
Follistatin-344 Beginners Guide: Isoform and Application Comparison
Before designing a research protocol, understanding which follistatin variant matches your experimental model is essential. The table below compares the two primary isoforms and their typical research applications. Amino Acid Count 315 residues 344 residues (i
No winner is assigned.
This page preserves a source comparison for education. It does not add a rating, recommendation or clinical judgment.
- Before designing a research protocol, understanding which follistatin variant matches your experimental model is essential. The table below compares the two primary isoforms and their typical research applications.
- Amino Acid Count
- 315 residues
- 344 residues (includes 29-AA C-terminal extension)
- Isoform selection depends on desired biodistribution
- Tissue Binding
- High affinity for heparan sulfate. Remains tissue-bound
- Low heparin affinity. Enters systemic circulation
- FS-315 for localized studies; FS-344 for whole-body models
- Half-Life
- 2–4 hours (localized clearance)
- 28–32 hours (systemic circulation)
- FS-344 supports less frequent dosing in extended protocols
- Bioavailability (SubQ)
- Minimal systemic exposure
- 60–75% reaches circulation
- FS-344 required for metabolic and multi-tissue research
- Myostatin Binding Affinity
- IC50 20–50 ng/mL (equivalent between isoforms)
- Both equally effective at neutralizing myostatin at receptor level
- Primary Use Cases
- Wound healing, localized muscle injury, fibrosis studies
- Systemic muscle hypertrophy, cachexia models, metabolic research
- Match isoform to whether effect needs to be local or systemic