PinnyPeptide

Follistatin vs GDF-8 95 (Myostatin Inhibitor)

Side-by-side comparison: effects, dosing ranges, side effects, regulatory status, and reconstitution.

Peptide A

Follistatin

Muscle Growth

Endogenous activin/myostatin binding protein — the gene-therapy myostatin inhibitor.

Peptide B

GDF-8 95 (Myostatin Inhibitor)

Muscle Growth

Short-peptide myostatin inhibitor targeting the GDF-8 / activin RIIB pathway.

Typical vial

1 mg

Typical dose

100-300 mcg

Half-life

~30 minutes (recombinant); years (AAV expression)

FDA status

Not FDA approved as recombinant protein. AAV-Follistatin gen…

Typical vial

1 mg

Typical dose

50-200 mcg

Half-life

Variable / poorly characterized for short-peptide formulations

FDA status

Not FDA approved.

Follistatin effects

  • Binds and neutralizes myostatin, activin A, and GDF-11
  • Promotes skeletal muscle hypertrophy
  • Increases muscle fiber size and strength
  • May enhance recovery from muscle injury
  • Sustained effect when delivered via AAV gene therapy

GDF-8 95 (Myostatin Inhibitor) effects

  • Theoretical inhibition of myostatin signaling
  • Potential muscle hypertrophy via removal of myostatin brake
  • Limited direct evidence for short-peptide formulations in humans
  • Mechanistic rationale supported by pathway biology

Follistatin side effects

  • Limited human safety data for recombinant protein
  • Theoretical disruption of HPG axis (activin binding)
  • Injection-site reactions
  • Potential off-target effects on tissues using activin signaling

GDF-8 95 (Myostatin Inhibitor) side effects

  • Largely uncharacterized in humans
  • Theoretical: capillary leak if cross-reactivity with other TGF-β ligands occurs
  • Injection-site reactions
  • Possible immunogenicity (anti-drug antibody formation)

Follistatin dosing ranges

Research / muscle hypertrophy (recombinant)

100-300 mcg · Daily (SubQ) · 10-30 days per cycle

AAV gene therapy (clinical)

Single high-titer AAV infusion · One-time · Durable expression (years)

GDF-8 95 (Myostatin Inhibitor) dosing ranges

Research / muscle hypertrophy

50-200 mcg · Daily or twice-weekly (SubQ) · Per research protocol

Full Follistatin guide → Full GDF-8 95 (Myostatin Inhibitor) guide →

Follistatin vs GDF-8 95 (Myostatin Inhibitor) — common questions

What is the difference between Follistatin and GDF-8 95 (Myostatin Inhibitor)?

Follistatin: Endogenous activin/myostatin binding protein — the gene-therapy myostatin inhibitor. Typical dose 100-300 mcg. GDF-8 95 (Myostatin Inhibitor): Short-peptide myostatin inhibitor targeting the GDF-8 / activin RIIB pathway. Typical dose 50-200 mcg. Both fall under the Muscle Growth category.

Can you stack Follistatin and GDF-8 95 (Myostatin Inhibitor)?

Stacking Follistatin with GDF-8 95 (Myostatin Inhibitor) is a protocol-design question best raised with a clinician — it depends on your goal, current bloodwork, and whether both peptides target overlapping mechanisms. Both peptides should be tracked independently with separate injection sites and timing. PinnyPeptide supports multi-peptide stacks with automatic injection site rotation.

Which is dosed more frequently, Follistatin or GDF-8 95 (Myostatin Inhibitor)?

Follistatin is typically dosed: Daily (SubQ) for Research / muscle hypertrophy (recombinant); One-time for AAV gene therapy (clinical). GDF-8 95 (Myostatin Inhibitor) is typically dosed: Daily or twice-weekly (SubQ) for Research / muscle hypertrophy.

Are Follistatin and GDF-8 95 (Myostatin Inhibitor) FDA approved?

Follistatin: Not FDA approved as recombinant protein. AAV-Follistatin gene therapy in clinical trials. GDF-8 95 (Myostatin Inhibitor): Not FDA approved.

Related peptide comparisons

ace-031 vs follistatinb7-33 vs follistatinfollistatin vs igf-1-desfollistatin vs igf-1-lr3follistatin vs mgface-031 vs gdf-8-95

Tracking either of these?

Log doses, automate injection site rotation, and never lose track of where you last pinned. Free forever.

Get Started Free