In plain English
Follistatin is a protein your body makes that switches off myostatin, the signal that limits how much muscle you can build. Follistatin-344 is the form used in research. The idea is simple: release the brake and muscle can grow more easily.
What it's used for
- Muscle growth
- Breaking through training plateaus
- Muscle-wasting conditions (being studied)
Benefits
In animal studies, raising follistatin dramatically increased muscle size and strength. In early human gene-therapy studies for muscular dystrophy, it improved walking distance. Users report gains in muscle fullness and strength, though results vary.
How it works
In simple terms: myostatin stops muscles growing too big, and follistatin blocks myostatin.
Follistatin binds and inactivates myostatin and related proteins (including activin) in the TGF-beta family. Removing that brake allows muscle cells to grow and multiply. Because it also binds activin, it can lower FSH, a reproductive hormone.
Development history
- 1987: Discovered as a protein that suppresses FSH, which gave it its name.
- 1990s–2000s: Shown to block myostatin; animals with extra follistatin develop much more muscle.
- 2015: Gene therapy delivering follistatin improves walking in a small study of Becker muscular dystrophy.
Typical protocols
These ranges are what users commonly report.
| Use | Dose | Frequency | Length |
|---|---|---|---|
| Muscle growth | 100 mcg | Daily | 10–30 days |
Cycling
Short courses of 10–30 days, with long breaks between.
Administration options
Subcutaneous or intramuscular injection.
Reconstitution and dosing calculator
Usually comes in 1 mg vials, mixed with 1–2 mL of bacteriostatic water. It is a large, fragile protein: mix very gently.
Draw your syringe to
– units
- Volume to draw
- –
- Concentration
- –
- Each unit holds
- –
- Doses per vial
- –
Show the math
This tool does arithmetic only. It does not choose a dose or confirm that any substance is right for you. Double-check every result against your syringe and your clinician’s instructions.
Side effects and safety
- Users report few side effects; injection-site redness and fatigue are mentioned.
- May lower FSH and affect fertility.
- Long-term effects of blocking myostatin are unknown.
- Quality varies widely because it is hard to make; independent testing matters.
- People with active cancer are usually advised to avoid growth factors and growth hormone-raising compounds.
- Avoid during pregnancy and breastfeeding.
- Prohibited in competitive sport (WADA).
Common stacks
IGF-1 LR3 or growth hormone peptides: combined for muscle growth.
Storage
Powder: freeze or refrigerate. After mixing: refrigerate at 2–8 °C and use within about 2 weeks.
Compare with
- IGF-1 and MGF: push muscle growth forward; follistatin removes a brake.
- ACE-031: another myostatin blocker, tested in people but discontinued.
Frequently asked questions
Does it really work?
Animal and gene-therapy results are striking. Results from injected follistatin are less certain and vary, partly because product quality varies.
Why such short cycles?
Users keep cycles short because of cost, fragility and unknown long-term effects.
References
- Lee SJ, McPherron AC. Regulation of myostatin activity and muscle growth. Proc Natl Acad Sci USA. 2001;98(16):9306-9311.
- Mendell JR, et al. A phase 1/2a follistatin gene therapy trial for Becker muscular dystrophy. Mol Ther. 2015;23(1):192-201.