FS315 vs Methoxy PEG-Epoetin Beta

Head-to-head comparison of FS315 (Follistatin-315 (FS315)) and Methoxy PEG-Epoetin Beta (Methoxy polyethylene glycol-epoetin beta (CERA)) — benefits, dosing, side effects, research data, and where to buy.

PropertyFS315Methoxy PEG-Epoetin Beta
CategoryMuscle & PerformanceMuscle & Performance
Full NameFollistatin-315 (FS315)Methoxy polyethylene glycol-epoetin beta (CERA)
Molecular Weight~40 kDa≈60,000 Da
Half-LifeN/A; depends on construct/delivery~130 h
Amino Acids315165
Typical DoseResearch-only; no standardized human dose0.6 mcg/kg SC every 2 weeks or 1.2 mcg/kg SC monthly
RouteIntramuscular / research expression systemsSubcutaneous/IV
Purity≥98%≥98%
Studies Count9595
Research StatusPre-clinicalClinical

FS315 Benefits

  • activin neutralization
  • muscle growth signaling
  • anti-catabolic support
  • tissue repair modulation

Methoxy PEG-Epoetin Beta Benefits

  • long-acting erythropoiesis
  • stable hemoglobin
  • fewer injections
  • improved oxygen delivery

FS315 Dosing

Research-only recombinant/protein-expression studies|no standardized clinical dose|route varies by platform

Methoxy PEG-Epoetin Beta Dosing

0.6 mcg/kg SC every 2 weeks|1.2 mcg/kg SC monthly|Adjust based on hemoglobin

FS315 Side Effects

  • off-target endocrine effects
  • immune response risk
  • fluid balance changes

Methoxy PEG-Epoetin Beta Side Effects

  • hypertension
  • thromboembolism
  • headache

Research Overview

FS315

Follistatin-315 is a key reference isoform in studies of muscle anabolism and reproductive/endocrine biology. In muscle research, it is relevant because it suppresses activin and can indirectly blunt myostatin pathway output.

Methoxy PEG-Epoetin Beta

Clinical trials show predictable hemoglobin correction with a long dosing interval and sustained red-cell stimulation. Any VO2 max effect would be secondary to higher hemoglobin, not a direct ergogenic mechanism.

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Common Stacking Partners

FS315 stacks with:

CreatineVitamin DLeucine

Methoxy PEG-Epoetin Beta stacks with:

IronVitamin B12
follistatinactivin-inhibitormyostatin-pathwayproteinerythropoiesisvo2-maxendurancepegylated