Follistatin 344
Get a source-linked, educational explanation from this profile.
Complete Research Guide
Open each section for the available evidence. Gaps are stated rather than inferred.
Overview
Follistatin 344 is listed as regenerative / myokine modulator.
- •Muscle growth
- •Anti-fibrotic
- •Fertility (research)
Regulatory status: Not FDA-approved; research use only.
Structure & Properties
Compound: Follistatin 344; also known as FST-344.
Pharmacologic class: Regenerative / Myokine Modulator.
Known delivery routes: Intramuscular, Subcutaneous.
Sequence, molecular weight, salt form, and excipient details are formulation-specific and are not listed unless verified by a manufacturer or laboratory COA.
How It Works
Activin/myostatin antagonist — binds and neutralizes myostatin and activin A; promotes satellite-cell activation and muscle hypertrophy; reduces fibrosis.
- •Muscle hypertrophy in models
- •Anti-fibrotic
- •Potential for sarcopenia (theoretical)
Human Research
Evidence grade: Pre-clinical / Observational
Evidence is primarily preclinical or observational; human effectiveness and long-term safety are not established.
Laboratory Research
Gene therapy trials ongoing; limited protein-form human data
Preclinical findings describe biological plausibility, not proven benefit in people. Animal and laboratory doses do not translate directly to human use.
Processing & Interactions
Timing and exposure
Once daily short cycles (10–30 days). Timing of day is not critical.
Potential interactions and combinations to avoid
- •Active malignancy
- •Concurrent anabolic hormone therapy without oversight
Absorption, half-life, metabolism, and clearance can vary by formulation and route. Use prescribing information when an approved product exists.
Safety & Precautions
Known or reported risks
- •Oncogenicity concern (myostatin suppression)
- •Gene-therapy safety unknowns
- •No approved human dosing
Contraindications
- •Active malignancy
- •Pregnancy
- •Pediatric
- •History of any solid tumor or hematologic malignancy
- •Bleeding disorders, epistaxis, or anticoagulant/antiplatelet therapy (telangiectasia risk)
- •Cardiac hypertrophy, cardiomyopathy, or valvular disease
- •Pre-existing tendon or ligament pathology (strength gain outpaces connective-tissue adaptation)
- •Bleeding disorders or anticoagulant therapy without physician guidance (injection-site haematoma)
- •Active skin infection, cellulitis, or lipohypertrophy at intended injection sites
- •Inability to maintain sterile technique or safe sharps disposal
- •Not FDA-approved for human therapeutic use — no verified purity, sterility, or potency standards
- •Immunocompromised or transplant patients (unverified sterility and immunogenicity risk)
- •Concurrent participation in drug-tested sport (WADA prohibited or non-cleared substance)
- •Known hypersensitivity or prior reaction to this compound or any excipient/diluent
- •Pregnancy, attempting conception, or breastfeeding unless prescribed and monitored by a physician
- •Children and adolescents with open growth plates (unless under specialist endocrine care)
- •Active or recently treated malignancy without oncology clearance
- •Use without a confirmed diagnosis, baseline labs, and licensed clinical supervision
Unknown long-term toxicity should be assumed where controlled human data are limited. Seek urgent care for a severe or unexpected reaction.
Administration & Studied Formulations
Reference range: 100 mcg/dose (experimental)
Frequency: Variable (research protocols only)
Cycling: Research protocols only — not for routine use.
Intramuscular (IM)
Used for depot formulations, some GH secretagogues (localized delivery), and clinical protocols requiring faster systemic uptake.
23–25G × 1–1.5" needle. 1–3 mL syringe. Ventrogluteal, vastus lateralis, or deltoid. Insert 90°, aspirate (optional), inject slowly. Rotate sites weekly.
Subcutaneous (SubQ)
Default route for most research and therapeutic peptides — best absorption for reconstituted powder.
31G × 5/16" insulin syringe (U-100). 100 units = 1 mL. Pinch skin at abdomen (2" from navel), outer thigh, or love handle. Insert at 45–90°. Rotate sites daily to prevent lipohypertrophy. Alcohol-swab site, air-dry, inject slow, hold 5 sec.
Dosing information is educational context, not a personal recommendation. Approved products must follow their label and prescriber instructions.
Applications & Related Therapies
Potentially complementary measures
- •GH secretagogue stacks for lean mass cycles
Clinical use should account for diagnosis, approved alternatives, nutrition, activity, sleep, rehabilitation, current medicines, and appropriate monitoring.
Cases, Considerations & Ethics
Decision framework: establish the clinical goal, confirm evidence quality and legal status, screen contraindications and interactions, compare approved alternatives, define monitoring and stopping criteria, and use shared decision-making with a licensed clinician.
Case evidence: individual reports cannot establish safety or effectiveness and should not outweigh controlled trials.
Ethics: informed consent should distinguish established care from experimental use, disclose uncertainty and cost, avoid overstated claims, and never substitute research products for medically necessary care.
What is Follistatin 344?
In plain words
Follistatin 344 is a precursor that the body processes into follistatin, a protein that controls certain growth signals. It binds proteins such as myostatin, which normally helps limit muscle growth. Researchers study it for increasing muscle size and reducing excess scar tissue. Human benefits are not established, and long-term risks—including possible effects on tumor biology and risks from gene-based delivery—remain uncertain.
Technical definition
Follistatin 344 (FST-344) is a 344-amino-acid precursor of the endogenous glycoprotein follistatin; removal of its 29-amino-acid signal peptide produces mature FST-315. Follistatin binds activin A and myostatin, preventing their receptor signaling, and is studied for effects on satellite cells, muscle hypertrophy, and fibrosis. FST-344 is not FDA-approved and remains research-only, with evidence largely preclinical and important uncertainties about long-term safety and gene-based delivery.
Function
Dosing
Recommended Time of Day
Morning, fasted — short 10-day research cycles.
See “Timing & Interactions” below for full fasted/fed circumstances, what to avoid combining, and what pairs well.
Administration & Technique
Injection & Application Sites
- Ventrogluteal — Palm on greater trochanter, index to ASIS — inject in the V. Safest IM site.
- Dorsogluteal (upper outer) — Upper outer quadrant of the buttock. Used for depot IM; alternate sides each cycle.
- Upper arm / deltoid — Back of the upper arm for SubQ; 2 in below the shoulder bone for IM.
- Anterior thigh (vastus lateralis) — Middle third of the outer front thigh. Preferred IM site for self-injection.
- Abdomen — 2 in (5 cm) away from the navel, either side. Fastest, most consistent SubQ absorption.
- Flank / love handle — Lateral fat pad above the hip. Good rotation site when the abdomen is tender.
- Outer thigh — Upper outer quadrant, a hand-width below the hip. SubQ pinch at 45°.
Diagram is a general illustration, not a medical instruction. Rotate sites every injection, keep 1 in (2.5 cm) between recent sites, and avoid scars, moles, bruises and the navel area.
Cycling
Research protocols only — not for routine use.
Timing & Interactions
- ·Active malignancy
- ·Concurrent anabolic hormone therapy without oversight
- ·GH secretagogue stacks for lean mass cycles
Storage & Reconstitution
Reconstitution Calculator
1 mL = 100 units on a standard U-100 insulin syringe. Draw to the nearest 0.5 unit and confirm dosing with a clinician before injection.
Your Notes
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Benefits
- ·Muscle hypertrophy in models
- ·Anti-fibrotic
- ·Potential for sarcopenia (theoretical)
Risks
- ·Oncogenicity concern (myostatin suppression)
- ·Gene-therapy safety unknowns
- ·No approved human dosing
Contraindications
- ·Active malignancy
- ·Pregnancy
- ·Pediatric
- ·History of any solid tumor or hematologic malignancy
- ·Bleeding disorders, epistaxis, or anticoagulant/antiplatelet therapy (telangiectasia risk)
- ·Cardiac hypertrophy, cardiomyopathy, or valvular disease
- ·Pre-existing tendon or ligament pathology (strength gain outpaces connective-tissue adaptation)
- ·Bleeding disorders or anticoagulant therapy without physician guidance (injection-site haematoma)
- ·Active skin infection, cellulitis, or lipohypertrophy at intended injection sites
- ·Inability to maintain sterile technique or safe sharps disposal
- ·Not FDA-approved for human therapeutic use — no verified purity, sterility, or potency standards
- ·Immunocompromised or transplant patients (unverified sterility and immunogenicity risk)
- ·Concurrent participation in drug-tested sport (WADA prohibited or non-cleared substance)
- ·Known hypersensitivity or prior reaction to this compound or any excipient/diluent
- ·Pregnancy, attempting conception, or breastfeeding unless prescribed and monitored by a physician
- ·Children and adolescents with open growth plates (unless under specialist endocrine care)
- ·Active or recently treated malignancy without oncology clearance
- ·Use without a confirmed diagnosis, baseline labs, and licensed clinical supervision
Regulatory
Not FDA-approved; research use only
Veterinary Use (Pets)
No established veterinary protocol for Follistatin 344. Consult a licensed veterinarian before considering off-label use in any species.
Full veterinary reference →Functional Groups
Cited Works
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