Specialized Research

Follistatin-315

Also known as: FS-315, FST-315

Molecular Identifiers

Molecular Weight

~35 kDa

Overview

315-amino acid isoform of follistatin with preferential selectivity for myostatin over activin. Considered more specific for muscle growth with less impact on the reproductive and endocrine axes.

Protein of 315 amino acids. Shorter isoform of Follistatin-344.

Half-life

~1.5-2 hours

Administration Route

Subcutaneous

Mechanism of Action

Selective myostatin inhibition
Lower affinity for activin compared to FS-344
Promotion of muscle hypertrophy
Less interference with the reproductive hormonal axis

Dosage Protocol

Data compiled from the literature. This does not constitute medical advice.

Parameter	Value
Dose	100-200 mcg per injection
Frequency	Once daily
Timing	Morning or post-workout
Duration	10-30 days

Reported Side Effects

Adverse effects described in the literature. Severity and frequency vary between individuals.

Injection site redness
Fatigue
Headache

Product Properties

Purity	>97%
Appearance	White lyophilized powder
Solubility	Soluble in water and bacteriostatic water. Reconstitute gently — do not vortex.
Source	Recombinant DNA technology (E. coli or HEK293 cells)
Storage	Lyophilized: -20°C for up to 2 years, 2-8°C for up to 6 months. Reconstituted: 2-8°C for up to 2 weeks. Protect from light and moisture. Avoid repeated freeze-thaw cycles. Aliquot for long-term storage.