ACE-031 vs FS315

Head-to-head comparison of ACE-031 (ACE-031 (soluble activin receptor type IIB-Fc)) and FS315 (Follistatin-315 (FS315)) — benefits, dosing, side effects, research data, and where to buy.

Research Score

PropertyACE-031FS315
CategoryMuscle & PerformanceMuscle & Performance
Full NameACE-031 (soluble activin receptor type IIB-Fc)Follistatin-315 (FS315)
Molecular Weight~95 kDa~40 kDa
Half-LifeDays to weeksN/A; depends on construct/delivery
Amino AcidsN/A315
Typical Dose0.1-3 mg/kg in early studiesResearch-only; no standardized human dose
RouteSubcutaneousIntramuscular / research expression systems
Purity≥98%≥98%
Studies Count7595
Research StatusClinicalPre-clinical

ACE-031 Benefits

  • myostatin/activin neutralization
  • lean mass gain
  • muscle function support
  • anti-catabolic effect

FS315 Benefits

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

ACE-031 Dosing

Clinical studies used single or repeated SC doses|dose escalation in mg/kg|monitoring for edema/bleeding

FS315 Dosing

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

ACE-031 Side Effects

  • telangiectasia/vascular effects
  • epistaxis
  • headache/edema

FS315 Side Effects

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

Research Overview

ACE-031

ACE-031 produced increases in lean mass in early studies, but development was curtailed after safety concerns and variable efficacy. Its literature remains important because it validated activin receptor blockade as a muscle-building strategy.

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.

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Common Stacking Partners

ACE-031 stacks with:

CreatineVitamin DLeucine

FS315 stacks with:

CreatineVitamin DLeucine
actr2b-decoymyostatin-inhibitorlean-massfusion-proteinfollistatinactivin-inhibitormyostatin-pathwayprotein