Last reviewed: October 2026 · Cleared Peptides research team
Follistatin is a secreted glycoprotein that binds and neutralizes members of the TGF-β superfamily, notably activins and myostatin (GDF-8). Follistatin-344 refers to the 344-amino-acid precursor of the FST315 isoform (315 residues after signal-peptide removal).
Follistatin-344 Structure and Identifiers
| Name | Follistatin-344 |
|---|---|
| Synonyms | FST-344 |
| CAS number | Not available. A single small-molecule CAS number is not assigned because this material is a recombinant protein preparation. |
| Type | Recombinant glycoprotein |
| Length | 344-amino-acid isoform precursor |
| Form | Lyophilized powder |
Isoforms
Alternative splicing produces FST288 and FST315 (from 317/344-residue precursors). The isoforms differ in a C-terminal acidic tail that affects heparan-sulfate binding and therefore tissue localization in research models.
Published In-Vitro Research Areas
- Activin and myostatin neutralization assays
- SMAD2/3 reporter assays
- Comparison with ligand traps such as ACE-031
This summary describes laboratory research only and makes no claim about effects in humans or animals.
Purity Testing and Storage
Every lot of Follistatin-344 supplied by Cleared Peptides is tested by an independent laboratory for identity and purity (or composition, for multi-component preparations), and the lot Certificate of Analysis is published on our COA page. Store lyophilized Follistatin-344 at −20 °C, sealed, dry and protected from light. Allow the vial to reach room temperature before opening and minimize freeze–thaw cycles. Handle according to your institution’s chemical-hygiene procedures.
Research materials referenced in this guide
Frequently Asked Questions
What does follistatin bind?
Activins, myostatin and several other TGF-β superfamily ligands.
Is Follistatin-344 for human use?
No. Cleared Peptides supplies Follistatin-344 for laboratory research use only; it is not for human or veterinary use.
Selected References
Peer-reviewed literature on the compounds discussed in this guide, listed as scientific background for laboratory researchers. Citation does not imply endorsement by the authors or any use other than in-vitro research.
- Schneyer A, et al. Follistatin-related protein (FSRP): a new member of the follistatin gene family. Mol Cell Endocrinol. 2001;180(1-2):33-8. PubMed 11451569 · DOI
- Hansen JS, et al. Circulating follistatin in relation to energy metabolism. Mol Cell Endocrinol. 2016;433:87-93. PubMed 27264073 · DOI
Laboratory note: solubility depends on salt form and solvent. This guide does not state a single solubility figure. Handling of lyophilized material is described in the peptide storage guide.
Research Use Only Notice
This guide is provided for educational and laboratory reference purposes. It summarizes published, primarily in-vitro and structural research literature and does not describe, recommend or imply any use in humans or animals. Products sold by Cleared Peptides are for laboratory research use only; they are not drugs, foods, cosmetics or dietary supplements, are not FDA-approved, and are not intended to diagnose, treat, cure, mitigate or prevent any disease. No dosing, administration or therapeutic information is provided.
