Follistatin is a single-chain gonadal protein that specifically inhibits follicle-
stimulating hormone release. The single FST gene encodes two isoforms, FST317
and FST344 containing 317 and 344 amino acids respectively, resulting from
alternative splicing of the precursor mRNA. In a study in which 37 candidate genes
were tested for linkage and association with polycystic ovary syndrome (PCOS) or
hyperandrogenemia in 150 families, evidence was found for linkage between PCOS
and follistatin. Follistatin binds directly to activin and functions as an activin
antagonist, specific inhibitor of the biosynthesis and secretion of pituitary follicle
stimulating hormone (fsh).
Follistatin 344 is a sterile, non-pyrogenic, white lyophilized powder intended for
subcutaneous or intramuscular injection, after reconstitution with sterile Water for
Mechanism of Action
Follistatin 344 is a naturally occurring human peptide and a potent inhibitor of
myostatin. Myostatin encourages the degradation of myotubes (skeletal muscle
fibers) therefore inhibition of myostatin will ultimately result in increased muscle
mass by preventing degradation. Follistatin is being studied for its role in regulation
of muscle growth, as an antagonist to myostatin (also known as GDF-8, a TGF
superfamily member). Lee & McPherron demonstrated that inhibition of GDF-8,
either by genetic elimination (knockout) or by increasing the amount of follistatin,
resulted in greatly increased muscle mass. In 2009, research with macaque
monkeys demonstrated that regulating follistatin via gene therapy also resulted in
muscle growth and increases in strength. A study has also shown that increased
levels of follistatin, by leading to increased muscle mass of certain core muscular
groups, can increase life expectancy in cases of spinal muscular atrophy (SMA) in
animal models. It is also being investigated for its involvement in polycystic ovary
syndrome (PCOS), though there is debate as to its direct role in this infertility disease.
Follistatin appears to have minimal side effects, may cause skeletal muscle growth
of up to 400% (based on the gene knockout experiments) and acts fast.
Instructions for reconstitution
Flip off the top of the peptide vial with your thumb. Use the alcohol swab to wipe the
rubber stopper of the peptide vial. Push the needle of the syringe into the middle of the
rubber stopper so it goes through the rubber and into the vial. Now, while angling the
needle so that the water for injection goes down the side of the glass, rather than
directly into the powder, inject the water for injection into the vial. Repeat this step until
you have the correct amount of water in the vial. The powder will dissolve quickly,
however it can help to gently roll the vial in between your fingers (do not shake the vial
vigorously). Remove the syringe and dispose of it. You should never re-use a syringe.
Recommended dosage of Follistatin 344:
- 50 — 100 mcg once per day.
- After reconstitution, may be stored for a maximum of 14 days in a refrigerator at 2°C — 8°C.
- Store vials in an upright position.
- Store in a refrigerator (2°C — 8°C). Keep in the outer carton in order to protect from light.
- For one month can be stored at room temperature.