FST 344 - Front - MiPeptidos
Specialty / Research

FST 344

CAS: 80449-31-6

FST 344 is a research peptide in the specialty / research category. Follistatin 344 is the full-length isoform of follistatin, a secreted glycoprotein that acts as a potent antagonist of activin, myostatin (GDF-8), and other TGF-beta superfamily ligands. MiPeptidos offers FST 344 in 1 sizes with 99.4% verified purity and full analytical documentation.

Starting at
$80.95/vial
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≥99% Purity
COA Included
Third-Party Tested
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CoA Included
HPLC Verified
GMP Compliant
Third-Party Tested
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How FST 344 Works

Follistatin 344 is the full-length isoform of follistatin, a secreted glycoprotein that acts as a potent antagonist of activin, myostatin (GDF-8), and other TGF-beta superfamily ligands. It binds these ligands with high affinity, preventing their interaction with cell-surface receptors and neutralizing their biological activity. By inhibiting myostatin, FST-344 removes the major endogenous brake on muscle growth, leading to increased muscle mass (muscle hypertrophy). The 344-isoform has lower heparin affinity than FST-288, giving it broader systemic distribution.

Research Applications

1
Myostatin inhibition and muscle hypertrophy
2
Muscular dystrophy and muscle wasting
3
Activin signaling antagonism
4
Reproductive biology (activin regulation of FSH)
5
Gene therapy vector for muscle disorders
View Published Research on PubMed →

Pricing

SizePer Vial10-Pack
1mg
$80.95$590.95

Prices shown per vial from 10-pack. Volume discounts available for 50+ vials — contact us.

HPLC Purity Analysis

High-Performance Liquid Chromatography
99.4%purity
mAURetention Time (min)0250500750100005101520253099.4%
Method: RP-HPLC C18 ColumnDetection: UV 220nmMobile Phase: Acetonitrile/Water + 0.1% TFA

Certificate of Analysis

MiPeptidos
FST 344
PASSES ALL SPECIFICATIONS
Batch NumberHR-FST3-2600215
Date of AnalysisJanuary 20, 2026
Purity (HPLC)99.4%
AppearanceWhite to off-white lyophilized powder
SolubilityFreely soluble in sterile water and bacteriostatic water
Molecular Weight (MS)~38,000 Da (full-length protein) — Confirmed
Endotoxin (LAL)<0.1 EU/mg
Sterility (USP <71>)Passes USP <71>

This COA is a representative sample. A batch-specific Certificate of Analysis with full HPLC chromatograms and mass spectrometry data is included with every MiPeptidos order.

Reconstitution Calculator

Add this much bacteriostatic water:
1.0 mL
1 mg FST 344 + 1.0 mL BAC water = 1 mg/mL

Inject bacteriostatic water slowly along the vial wall. Gently swirl until dissolved — never shake. Store reconstituted solution at 2-8°C and use within 30 days.

Download Product Brochure

Get our detailed FST 344 product brochure with specifications, research applications, HPLC analysis data, and reconstitution guide. Available in English and Spanish.

Customer Reviews

5.0/5from 1 review
Verified
Dr. David Martinez·Madrid, Spain

FST-344 from MiPeptidos is the follistatin isoform we use for myostatin and activin inhibition studies. The 344-amino-acid variant performed beautifully in our activin-binding assays with expected neutralization kinetics...

Nov 25, 2025
View All Reviews →

Frequently Asked Questions

FST 344 (CAS: 80449-31-6) is a research compound, with a molecular weight of ~38,000 Da (full-length protein) in the Specialty / Research category. Follistatin 344 is the full-length isoform of follistatin, a secreted glycoprotein that acts as a potent antagonist of activin, myostatin (GDF-8), and other TGF-beta superfamily ligands. It binds these ligands with high affinity, preventing their interaction with cell-surface receptors and neutralizing their biological activity. Researchers commonly investigate FST 344 for Myostatin inhibition and muscle hypertrophy, Muscular dystrophy and muscle wasting, Activin signaling antagonism. Every vial from MiPeptidos includes batch-specific analytical documentation.
To reconstitute your FST 344 1mg vial, let it reach room temperature for about 15-20 minutes out of the freezer. Slowly inject 1mL of bacteriostatic water along the inside wall of the vial — never aim directly at the peptide cake. Gently swirl until the powder fully dissolves; never shake, as this can denature the peptide. Store reconstituted FST 344 at 2-8°C and use within 30 days. MiPeptidos includes bacteriostatic water for purchase alongside all peptides.
FST-344 (Follistatin 344, ~38,000 Da) is the full-length follistatin glycoprotein that directly binds and neutralizes myostatin, activin, and other TGF-beta ligands. ACE-031 (~57,320 Da) is a soluble ActRIIB-Fc decoy receptor that traps the same ligands but through receptor mimicry. FST-344 has lower heparin affinity than the FST-288 isoform, giving it broader systemic distribution. FST-344 is also being studied as a gene therapy vector. MiPeptidos offers both myostatin inhibitors.
Store lyophilized FST 344 at -20°C for maximum long-term stability — properly stored, it remains potent for 24+ months. Once reconstituted with bacteriostatic water, keep it refrigerated at 2-8°C and use within 30 days. In research applications, FST 344 has a reported half-life of Short; hours in circulation (rapidly cleared), which informs dosing frequency and protocol design. Avoid repeated freeze-thaw cycles and protect from direct light. MiPeptidos ships every order with cold-chain packaging to maintain integrity during transit.
Every FST 344 order from MiPeptidos includes a batch-specific Certificate of Analysis. Our current batch (HR-FST3-2600215, tested January 20, 2026) shows 99.4% purity by HPLC, mass spectrometry confirmation at ~38,000 Da (full-length protein), endotoxin levels below 0.1 EU/mg, and passing sterility per USP <71>. This level of documentation ensures you can verify compound identity and purity before beginning your research. MiPeptidos also offers bulk pricing on orders of 50+ vials — contact info@mipeptidos.com.

Specifications

Purity
≥99%
Form
Lyophilized Powder
CAS Number
80449-31-6
Mol. Weight
~38,000 Da (full-length protein)
Formula
Protein (~344 amino acids)
Half-Life
Short; hours in circulation (rapidly cleared)
Storage
Store at -20°C. Reconstituted: 2–8°C for up to 30 days.
Sizes
1mg

Sequence

344-amino acid glycoprotein containing follistatin domains and a C-terminal acidic tail; binds activin and myostatin

Research Use Only. This product is intended for laboratory research purposes only. Not for human consumption. Handle with appropriate safety precautions.

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