What is Follistatin??
Follistatin (FST-344, CAS 122956-17-2) is a single-chain glycoprotein (MW ~35 kDa for FST-344 isoform) belonging to the TGF-β superfamily binding protein class. It acts as a potent endogenous inhibitor of activins, myostatin (GDF-8), GDF-11, GDF-9, and BMPs by binding these ligands with high affinity and sequestering them from their receptors. FST-344 is the circulating, proteoglycan-binding–deficient isoform with broader systemic distribution than FST-288. It is a key research tool for studying muscle hypertrophy, fertility (FSH/activin axis), bone formation, and TGF-β pathway biology.
Research Applications
Myostatin Inhibition
GDF-8 sequestration, muscle fibre hypertrophy, atrophy model reversal — compared to ACE-031 and MSTN antibodies
Activin/FSH Axis
Activin A/B neutralisation, FSH suppression in pituitary research, ovarian folliculogenesis
Bone Formation
BMP-2/4/7 modulation, osteoblast differentiation, bone mineral density studies
Reproductive Biology
Gonadal steroidogenesis, spermatogenesis, granulosa cell function, follicle dynamics
TGF-β Superfamily Profiling
Broad ligand-trap characterisation across activin, GDF, and BMP family members
Quick Specs
| Form | Lyophilized powder |
| Purity | ≥99% by HPLC — every batch |
| CAS Number | 122956-17-2 |
| Isoform | FST-344 (systemic, heparin-low-affinity isoform) |
| Molecular Weight | ~35 kDa (glycosylated) |
| Peptide Type | Recombinant glycoprotein / TGF-β superfamily ligand trap |
| Identity | MS molecular weight confirmed — every batch |
| COA | Janoshik-independent, publicly verifiable |
| Manufacture | In-house Fmoc SPPS — Qingdao, China |
| Storage | -20°C sealed | 2–8°C reconstituted (2–4 weeks) |
| Shelf Life | 24 months unopened |
