Follistatin 344

Estimated Market Price

$149.99 – $164.99

Based on verified supplier pricing for research-grade compounds

Myostatin inhibitor that removes the biological limit on muscle growth. Neutralizes myostatin to unlock enhanced muscle development and tissue repair.

How it works

Traps and neutralizes myostatin, the protein that naturally limits how much muscle your body builds. Removing this brake allows significantly greater muscle growth and may also reduce inflammation.

Performance

What to Expect

Days 1–5 Myostatin binding begins; molecular brake on growth releasing. Muscles feel slightly fuller during workouts.

Days 6–15 Muscle protein synthesis upregulated; strength gains starting. Strength creeping up; pumps feel bigger and harder.

Days 16–25 Visible muscle fullness; accelerated lean mass accrual. Visible muscle growth; looking noticeably more muscular.

Days 26–30 Peak myostatin inhibition; cycle completing for assessment. Peak fullness and strength; muscles feel dense.

Verified Suppliers

For research purposes only. These suppliers have been independently verified by PepSpace. We do not process sales directly.

PepSpace is not affiliated with any listed supplier

LarnaLabs Verified Supplier · larnalabs.com

PepSpace Verified Supplier · pepspace.io

BioSynth Verified Custom Batch Supplier · biosynth.com

Peptide Sciences Unavailable · peptidesciences.com

Protocol & Dosage

Typical Dosage 100–300 mcg SC daily

Administration Subcutaneous injection

Schedule Once daily, AM or post-workout

Protocol Duration 10–30 days

Half-Life ~4 hours

Side Effects & Safety

Tolerability Profile Moderate

Notable side effects likely; manageable with proper awareness

Common Side Effects

Injection site reactionmost users
Mild water retentionsome users

Less Common

Fatigueoccasional
Joint discomfortoccasional
Headacheoccasional
Mild tinglingoccasional

Discontinue If

Severe muscle pain or swelling
Cardiac symptoms (follistatin affects cardiac remodeling)
Signs of hormonal imbalance

Contraindications

Active cancer or tumors
Cardiac conditions (hypertrophic cardiomyopathy)
Pregnancy or breastfeeding

Data note: Myostatin inhibitor that promotes muscle growth. Long-term effects of myostatin inhibition on cardiac tissue are not fully understood.

Always consult a qualified healthcare professional before use. This information is for research reference only and does not constitute medical advice.

Ask about Follistatin 344

How to Apply

Gather

Peptide vial, BAC water, alcohol swabs, insulin syringe

Sanitize

Wipe tops of both vials with alcohol swabs

Draw

Pull 1–2 mL of BAC water into syringe

Add Water

Release water slowly along vial wall, not directly on powder

Swirl

Roll between palms until dissolved. Never shake.

Store

Refrigerate 2–8°C, use within 30 days

Frequently Asked Questions

Yes. Bacteriostatic water (BAC water) is required to reconstitute lyophilized (freeze-dried) peptides. It contains 0.9% benzyl alcohol which prevents bacterial growth, keeping your reconstituted peptide safe for multiple uses over up to 30 days.

Unreconstituted: store at -20°C (freezer) for long-term, or 2–8°C (fridge) for short-term. After reconstitution: always refrigerate at 2–8°C and use within 30 days. Keep away from direct sunlight.

Results vary by individual and protocol. In research settings, measurable effects are typically observed within 1–4 weeks depending on the specific peptide, dosage, and application. Consult a qualified professional for guidance.

Verified suppliers typically include a full third-party COA verifying purity (99%+), identity, and sterility. We recommend only sourcing from vendors that provide batch-specific testing data.

We list verified suppliers above that have been independently reviewed for product quality, testing transparency, and shipping reliability. Always verify COA data before sourcing.

Compound Profile

Scientific data & classification for Follistatin 344

Also Known As FST-344, Follistatin, FS-344

Classification Glycoprotein · Myostatin Inhibitor

Sequence 344 amino acid glycoprotein (recombinant)

Molecular Formula Glycoprotein (~38 kDa)

Molecular Weight ~38,000 Da

CAS Number N/A (recombinant protein)

Half-Life ~4 hours

Origin Recombinant human follistatin protein

Administration Subcutaneous injection

Status Research compound - gene therapy clinical trials

Mechanism of Action Traps and neutralizes myostatin, the protein that naturally limits how much muscle your body builds. Removing this brake allows significantly greater muscle growth and may also reduce inflammation.

Research Overview Follistatin-344 (FST-344) is a recombinant glycoprotein consisting of 344 amino acids that functions as a potent endogenous antagonist of activin, myostatin, and other members of the transforming growth factor-beta (TGF-β) superfamily - a family of signaling molecules that play fundamental roles in regulating cell growth, differentiation, and tissue homeostasis. The protein was first identified and characterized in the late 1980s by researchers studying activin-binding proteins in follicular fluid, and its name derives from its ability to suppress follicle-stimulating hormone (FSH) secretion by neutralizing activin in the pituitary gland. The most widely studied function of follistatin in contemporary research is its ability to bind and neutralize myostatin (also known as GDF-8), a TGF-β family member that acts as a potent negative regulator of skeletal muscle mass. Myostatin signals through activin type II receptors on muscle cells to activate Smad2/3 transcription factors that suppress muscle protein synthesis and promote protein degradation. By sequestering myostatin with high affinity, follistatin effectively removes this natural brake on muscle growth, allowing dramatic increases in skeletal muscle mass. This mechanism was most dramatically demonstrated by Se-Jin Lee's group at Johns Hopkins, who showed that follistatin overexpression in transgenic mice produced a hypermuscular phenotype with individual muscles up to 327% of normal size. Gene therapy trials led by Jerry Mendell at Nationwide Children's Hospital have delivered follistatin via adeno-associated viral vectors (AAV) to patients with Becker muscular dystrophy and sporadic inclusion body myositis, showing improvements in the six-minute walk test and muscle biopsy measures of fiber size. Beyond muscle biology, follistatin-344 is the most broadly distributed isoform of follistatin and also plays roles in reproductive biology, liver protection, and wound healing. The protein's relatively short half-life of approximately 4 hours following subcutaneous injection limits its utility as a standalone therapeutic, driving interest in gene therapy approaches and modified formulations.

Citations

Published findings on Follistatin 344 from peer-reviewed journals.

Inhibition of myostatin with emphasis on follistatin as a therapy for muscle disease

Kota J, et al. • 2009 PubMed

The transgenic expression of human follistatin-344 increases skeletal muscle mass in pigs

Guo T, et al. • 2017 PubMed

Follistatin induces muscle hypertrophy through satellite cell proliferation and inhibition of both myostatin and activin

Gilson H, et al. • 2009 PubMed