What is Follistatin-315?

Circulating follistatin isoform (315 aa). Same myostatin/activin neutralization as FS-344 but shorter half-life due to loss of heparin-binding C-terminus. Follistatin-315 neutralizes myostatin, activin A, and GDF-11. Unlike FS-344, it lacks the heparin-binding C-terminal domain, so it is not retained on cell surfaces and has a shorter serum half-life.

What is Follistatin-315 used for?

Reported uses include myostatin neutralization for hypertrophy and useful as research reagent. Evidence strength is rated Preclinical — see the evidence section for detail.

How is Follistatin-315 dosed?

Commonly referenced dosing is Not characterized in humans, typically research, administered SubQ. This is educational reference only; consult a licensed clinician before use.

What are the side effects of Follistatin-315?

Commonly reported side effects include unknown in humans and theoretical cardiac risk (myostatin signaling). This list is not exhaustive.

Follistatin-315 | Peptide Guide

§ 01 Overview

Overview

Circulating follistatin isoform (315 aa). Same myostatin/activin neutralization as FS-344 but shorter half-life due to loss of heparin-binding C-terminus.

Biology well-characterized; no approved therapeutic form.

§ 02 Mechanism

Mechanism of action

Follistatin-315 neutralizes myostatin, activin A, and GDF-11. Unlike FS-344, it lacks the heparin-binding C-terminal domain, so it is not retained on cell surfaces and has a shorter serum half-life.

01Myostatin neutralization for hypertrophy
02Useful as research reagent

§ 03 Dosing

Dosing protocol

Standard Protocol

Dose Range: Not characterized in humans
Route: SubQ
Frequency: Research

§ 04 Evidence

Evidence & research

Preclinical

Biology well-characterized; no approved therapeutic form.

FDA Status

Not FDA-approved. WADA prohibited.

§ 05 Stacks

Common stacks

Follistatin-344

Longer-acting isoform

§ 07 Sourcing

Sourcing & supply

Regulatory status

Research-only, no commercial channel

No commercial channel exists. Available only as a research reagent from RUO suppliers. Use in humans is not established.

No suppliers in our directory currently stock this compound. For investigational or research-only compounds, legitimate channels may not exist outside clinical trials.

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§ 09 Safety

Safety & side effects

Side effects

01Unknown in humans
02Theoretical cardiac risk (myostatin signaling)

Contraindications

None specified.

§ 10 Questions

Follistatin-315 FAQ

What is Follistatin-315?: Circulating follistatin isoform (315 aa). Same myostatin/activin neutralization as FS-344 but shorter half-life due to loss of heparin-binding C-terminus. Follistatin-315 neutralizes myostatin, activin A, and GDF-11. Unlike FS-344, it lacks the heparin-binding C-terminal domain, so it is not retained on cell surfaces and has a shorter serum half-life.
What is Follistatin-315 used for?: Reported uses include myostatin neutralization for hypertrophy and useful as research reagent. Evidence strength is rated Preclinical — see the evidence section for detail.
How is Follistatin-315 dosed?: Commonly referenced dosing is Not characterized in humans, typically research, administered SubQ. This is educational reference only; consult a licensed clinician before use.
What are the side effects of Follistatin-315?: Commonly reported side effects include unknown in humans and theoretical cardiac risk (myostatin signaling). This list is not exhaustive.
Is Follistatin-315 legal?: No commercial channel exists. Available only as a research reagent from RUO suppliers. Use in humans is not established. FDA status: Not FDA-approved. WADA prohibited..

§ 11 References

Selected references

01
Hill Mol Endocrinol 2002
PMID: 18586835
02
Lee PNAS 2005
PMID: 16330774