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GH SecretagogueSubcutaneous
Follistatin-344
Also known as: FST-344 · FS-344
Truncated isoform of follistatin, a glycoprotein that binds and inactivates myostatin and activin A. Inhibition of myostatin removes a brake on muscle growth — animal models show substantial hypertrophy independent of training stimulus.
At a glance
- Half-life
- 30 hours
- Common route
- Subcutaneous
- Typical dose range
- 100–300mcg
- Stability (reconstituted)
- 14days refrigerated
Best timing
Daily or every other day in 10-day protocols. Limited human data — most evidence is from gene therapy and animal studies.
Contraindications
- Active cancer (myostatin has tumor-suppressive activity in some contexts)
- Pregnancy
- Cardiac disease (myostatin regulates cardiomyocyte mass)
- Limited human safety data
Watch symptoms
- Injection site reactions
- Theoretical cardiac hypertrophy with sustained use
- Tendon strain risk if muscle hypertrophy outpaces connective tissue adaptation
- Limited human pharmacokinetic data — actual potency unclear
Citations