# Follistatin 344 – 1mg/vial (Research Use Only)

Backed by the Research [Read: How Incretin and Growth-Hormone-Axis Compounds in the Literature →](https://portaltowellness.net/research/glp1-adjunct-peptide-research-guide/)

### Overview

Follistatin-344 is a naturally occurring isoform of follistatin, a secreted glycoprotein encoded by the FST gene that functions as a potent endogenous antagonist of myostatin (GDF-8) and other TGF-β superfamily members. By binding and neutralizing myostatin — the primary negative regulator of skeletal muscle mass — follistatin-344 has generated substantial published research interest in muscle biology, body composition research, and reproductive endocrinology.

### What It Is

Follistatin-344 is the 344-amino acid heparin-binding isoform of human follistatin, produced by alternative mRNA splicing of the FST gene. MW approximately 37–45 kDa (glycoprotein). It contains three follistatin domain (FSD) repeats that enable tight non-covalent binding to activin A, myostatin (GDF-8), GDF-11, and other TGF-β ligands, effectively sequestering them from their receptors.

### Key Research Applications

- Myostatin (GDF-8) binding and neutralization mechanism research
- Skeletal muscle hypertrophy signaling, satellite cell activation, and myogenesis studies
- TGF-β superfamily member antagonism (activin A, GDF-11, BMP) pathway research
- Follistatin isoform (FS-288, FS-315, FS-344) comparative binding and biological activity studies
- Reproductive axis research — FSH suppression, activin antagonism, and ovarian biology
- Muscle wasting disease modeling (cachexia, sarcopenia, muscular dystrophy preclinical models)
- Adipose tissue biology — myostatin/activin signaling in fat cell differentiation research
- Bone and cartilage biology — BMP-2/4/7 regulation and osteogenesis research

### Technical Specifications

| Protein | Follistatin-344 (FST gene, isoform 344) |
| --- | --- |
| Amino Acids | 344 |
| Molecular Weight | ~37–45 kDa (glycoprotein) |
| Primary Target | Myostatin (GDF-8), Activin A, GDF-11 |
| Mechanism | TGF-β Superfamily Ligand Antagonist |
| Purity | ≥95% (supplier specification) |
| Form | Lyophilized powder |
| Vial Size | 1mg |
| Storage | −112 °F long-term; −4 °F short-term; avoid repeated freeze-thaw |

**FOR RESEARCH USE ONLY.** Not intended for human or veterinary consumption, medical diagnosis, treatment, or prevention of any disease or condition. This product has not been evaluated by the FDA or any regulatory agency. Must be handled by qualified research personnel in a compliant laboratory setting. These statements have not been evaluated by the Food and Drug Administration.

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