Follistatin-344
A myostatin inhibitor that unlocks muscle growth beyond genetic limits. Follistatin-344 is a synthetic version of the naturally occurring follistatin protein that inhibits myostatin and activin signaling. By blocking these muscle-growth suppressors, it promotes significant increases in lean muscle mass. Widely researched for muscle-wasting conditions, athletic performance, and body composition.
Compare Prices🧬Key Characteristics
- Length: 344 amino acids(Full-length isoform of follistatin.)
- Target: Myostatin (GDF-8)(Also binds activin A and GDF-11.)
- Mechanism: Ligand trap(Binds and sequesters TGF-β ligands.)
- Primary Use: Muscle growth(Removes genetic limits on hypertrophy.)
Overview
Core Benefits
Key AdvantagesThese are educational summaries of commonly discussed effects in wellness/regenerative contexts, not guarantees.
Follistatin-344 Results Timeline
ProgressionTimeline is illustrative and non-guaranteed. Outcomes vary and are commonly discussed alongside training, nutrition, sleep, and cycling practices.
How It Works
Myostatin Inhibitor — Muscle Growth PeptideTarget → Myostatin Inhibition → Muscle Growth → Outcomes
Myostatin & Activin (TGF-β Superfamily Ligands)
Follistatin-344 binds and neutralizes myostatin and activin — two proteins that actively suppress muscle growth. Myostatin acts as a "brake" on muscle development. By blocking the brake, Follistatin-344 allows muscle to grow beyond its normal genetic limit.
Myostatin/Activin Sequestration → Smad Pathway De-Repression
Follistatin binds myostatin before it can reach ActRIIB receptors on muscle cells. This prevents the Smad 2/3 signaling cascade that normally limits protein synthesis and satellite cell activation. With the brake removed, muscle cells enter an enhanced growth state.
Increased Muscle Protein Synthesis + Satellite Cell Activation
Without myostatin suppression, muscle fibers undergo both hypertrophy (bigger fibers) and hyperplasia (more fibers). Satellite cells — the muscle stem cells responsible for repair and growth — are activated at higher rates. Effects are seen across all skeletal muscle groups.
Lean Mass Gains → Strength → Improved Body Composition
Noticeable increases in lean muscle mass over weeks of use. Strength gains that exceed training alone. Improved body composition with favorable muscle-to-fat ratio changes. Effects are most pronounced when combined with resistance training.
What Makes This Peptide Different
Follistatin-344 is unique in targeting the natural limiter of muscle growthrather than stimulating growth directly. While GH peptides (CJC-1295, Ipamorelin) and IGF-1 LR3 push growth signals harder, Follistatin removes the ceiling. The FS-344 isoform undergoes cleavage to FS-315, which has broader tissue distribution than the FS-288 isoform. Naturally occurring — your body already produces follistatin, just not enough to override myostatin completely.
Dosing Protocol
Muscle Growth / Myostatin InhibitionEducational reference only. Individual responses vary. Consult healthcare provider before use.
Why This Dosing Protocol
Why short cycles (10-30 days)? Follistatin-344's potent myostatin suppression should be cycled to prevent potential off-target effects on other TGF-β pathways that follistatin also modulates (FSH suppression, for example).
Why combine with training? Myostatin inhibition removes the growth ceiling, but the growth signal still needs to come from somewhere — mechanical loading from resistance training provides the stimulus that follistatin allows the body to respond to more aggressively.
Follistatin-344 Pricing
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Reconstitution calculator
Dilution math and unit conversions. Prefilled using a common vial size for this peptide.
Open calculatorHandling
Educational overview on storage, labeling, and traceability considerations for lab environments. Consult primary literature and vendor documentation for specifics.
- Freezer (-20°C): 1+ year ✓
- Refrigerator (2-8°C): 1-3 months ✓
- Room temperature: 2-3 weeks (emergency only)
- MUST refrigerate at 2-8°C
- 4-week maximum shelf life
- NEVER freeze after reconstitution
- Use bacteriostatic water for multi-dose
Storage & Handling Guide
Learn proper storage temperatures, shelf life timelines, reconstitution best practices, and travel tips for lyophilized and reconstituted peptides.
FAQ
How does Follistatin-344 promote muscle growth?
Follistatin-344 binds and neutralizes myostatin (GDF-8), the protein that limits how much muscle your body can build. By removing this natural brake, FS-344 allows both hypertrophy (bigger muscle fibers) and potentially hyperplasia (more fibers). It also inhibits activin A, which has additional growth-suppressive effects.
What is the difference between Follistatin-344 and Follistatin-315?
FS-344 is the full-length isoform that gets cleaved in the body to produce FS-315 and FS-288. FS-315 is the primary circulating form and the most relevant for muscle effects. FS-288 binds more tightly to cell surfaces and is important in reproductive tissues. Research peptide vendors typically sell FS-344 as it produces both active forms.
How long are Follistatin-344 cycles?
Community protocols typically run 10–30 days due to the peptide's potency. Longer cycles aren't well-studied. Most users report noticeable strength and fullness gains within the first 2 weeks. Cycling off allows the body to re-establish baseline myostatin levels.
Is Follistatin-344 the same as the gene therapy used in muscular dystrophy trials?
Similar concept, different delivery. Gene therapy trials (like those by Mendell et al.) use AAV vectors to make muscles produce follistatin endogenously and permanently. Injectable FS-344 provides temporary exogenous follistatin that clears from the body. The gene therapy approach showed promising safety and efficacy in Becker muscular dystrophy patients.
Can Follistatin-344 be stacked with other peptides?
Some researchers combine FS-344 with growth hormone secretagogues (CJC-1295/Ipamorelin) or IGF-1 LR3 for synergistic muscle-building effects. The rationale is that FS-344 removes the growth ceiling while GH/IGF peptides provide the anabolic stimulus. Each should be injected separately.
How long does reconstituted peptide last?
Once mixed with bacteriostatic water, peptides remain stable for up to 4 weeks when refrigerated at 2-8°C (36-46°F). Unopened powder can last 1+ year in the freezer. Get our complete Storage & Travel Guide.
Is this peptide legal to purchase?
Peptides sold "for research purposes only" are legal to purchase in the US, but are not FDA-approved for human use outside of specific medical applications. Always consult a healthcare provider before use.
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