Side-by-side · Research reference
ARA 290vsFollistatin-344
Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.
APhase 2HUMAN-REVIEWED17/59 cited
BHuman-MechanisticHUMAN-REVIEWED4/58 cited
Follistatin-344
Myostatin/Activin Antagonist · Research Use
15–25%FST/MSTN ratio ↑
344 AACirculating isoform
ResearchPhase status
Research · No approved protocol
01Mechanism of Action
Parameter
ARA 290
Follistatin-344
Primary target
Innate repair receptor (EPO receptor / CD131 heterodimer)
Myostatin (MSTN/GDF-8) and Activin A
Pathway
EPO/CD131 → JAK2 activation → PI3K/AKT, MAPK signaling → anti-inflammatory, anti-apoptotic cascades
FST-344 binds MSTN/Activin → prevents ActRIIB receptor engagement → disinhibits muscle anabolism
Downstream effect
Tissue protection, nerve fiber regeneration, suppression of inflammatory macrophage activation, altered T-cell differentiation (↑Treg, ↑Th2, ↓Th1)Liu 2014Culver 2017
Elevated follistatin/myostatin ratio, increased muscle protein synthesis, attenuated muscle atrophy signalingJeong 2026
Feedback intact?
N/A — does not interact with hematopoietic EPO receptorLiu 2014
Yes — indirect antagonist, preserves endogenous regulation
Origin
11-amino-acid sequence from EPO helix B, engineered to eliminate hematopoietic activity while retaining tissue-protective properties
Endogenous glycoprotein, 344-AA isoform lacking heparin-binding domain (vs FST-315)
Antibody development
Not reported in clinical trials
Not documented in available trials (endogenous protein)
02Dosage Protocols
Parameter
ARA 290
Follistatin-344
Standard dose (Phase 2)
4 mg / dayBrines 2015Culver 2017
Sarcoidosis SFN and diabetic neuropathy trials.
—
Frequency
Once daily
Self-administered subcutaneously.
—
Evidence basis
Phase 2 RCTsCulver 2017Brines 2015
64-subject sarcoidosis trial, type 2 diabetes trial.
Human observational / biomarker studies
Timing
Any time of day
No circadian dependence reported.
—
Clinical protocol
—
None — no approved dosing regimen
Follistatin-344 measured as endogenous biomarker, not administered exogenously in cited trials.
Research context
—
Endogenous modulation via exercise + nutrition
Resistance training + EAA intake elevated FST/MSTN ratio by 15–25% in 12-week RCT (older women).
Half-life
—
Not established
Circulating isoform; lacks tissue-binding domain of FST-315.
03Metabolic / Fat Loss Evidence
Parameter
ARA 290
Follistatin-344
Primary effect
Improved metabolic control (HbA1c, fasting glucose)Brines 2015
Secondary to neuropathy treatment; direct lipolytic effects not established.
—
HbA1c
Significant reduction vs placebo
Observed in type 2 diabetes + neuropathy trial.
—
Fasting glucose
Improved in ARA 290 group
—
Body composition
Not directly quantified
Fat loss not a primary endpoint; metabolic improvements may reflect insulin sensitivity.
—
Primary target
—
Muscle mass preservation, not direct lipolysis
Indirect fat effect
—
Increased lean mass → elevated resting metabolic rate
Not primary mechanism. Muscle-sparing during deficit.
Clinical evidence
—
Lorcaserin trial (6 mo) showed no MAFI axis changes during fat lossRamirez-Cisneros 2026
Suggests follistatin not primary driver of fat loss in weight-reduction interventions.
GLP-1RA studies
—
Liraglutide (35 days) — no significant MAFI axis modulation despite fat/lean changes
04Side Effects & Safety
Parameter
ARA 290
Follistatin-344
Injection site reaction
Mild, transient
—
Hematopoiesis
None — non-erythropoietic
Distinguishes ARA 290 from native EPO.
—
Cardiovascular
No thrombotic events or hypertension reported
—
Immunogenicity
No antibody formation reported
—
Clinical safety data
—
None — no human exogenous administration trials in literature
Theoretical risks
—
Excessive myostatin inhibition → muscle overgrowth, impaired glucose tolerance
Based on myostatin-null animal models and clinical myostatin inhibitor trials.
Endogenous elevation (exercise)
—
No adverse effects reported in 12-week resistance + EAA trials
Cancer risk (theoretical)
—
Myostatin inhibition may promote tumor growth in malignancy (preclinical data)
Regulatory status
—
Not approved for human use — research peptide only
Absolute Contraindications
ARA 290
- ·Hypersensitivity to ARA 290
Follistatin-344
- ·Active malignancy
- ·No approved protocol — research use only
Relative Contraindications
ARA 290
- ·Active malignancy (theoretical EPO-axis concern; not observed in trials)
Follistatin-344
- ·Insulin resistance / Type 2 diabetes (monitor glucose)
- ·Pregnancy / lactation (unknown safety profile)
05Administration Protocol
Parameter
ARA 290
Follistatin-344
1. Preparation
Reconstitute lyophilised powder per manufacturer instructions. Use sterile technique.
Follistatin-344 is not approved for human administration. All cited studies measure endogenous serum follistatin as a biomarker, not as an exogenous therapeutic agent.
2. Injection site
Subcutaneous — abdomen, thigh, or upper arm. Rotate sites to avoid lipohypertrophy.
Resistance exercise combined with essential amino acid (EAA) supplementation elevated the follistatin/myostatin ratio by 15–25% in 12-week randomized trials. Protein intake (1.2–1.5 g/kg/day) synergizes with training to upregulate endogenous follistatin.
3. Timing
Once daily, any time of day. Self-administered in Phase 2 trials.Brines 2015
Serum follistatin and follistatin/myostatin ratio are used diagnostically in sarcopenia screening and as biomarkers of muscle anabolic balance in clinical trials.
4. Dosing
4 mg daily for 28 days (Phase 2 protocol). Duration for chronic use not established.Culver 2017
Gene therapy and recombinant follistatin delivery are under preclinical investigation for muscular dystrophy and sarcopenia. No human safety or efficacy data for exogenous FST-344 administration.
5. Storage
Lyophilised: store at controlled room temperature. Reconstituted: refrigerate, use within specified timeframe.
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06Stack Synergy
ARA 290
+ BPC-157
ModerateARA 290 targets the innate repair receptor (EPO/CD131) for nerve regeneration and anti-inflammatory signaling, while BPC-157 promotes angiogenesis and tissue repair through distinct mechanisms (likely involving VEGF, growth hormone receptor pathways). Combined, they may address both neuroinflammation and structural tissue repair in neuropathy or injury models. No direct clinical data; mechanistic overlap in tissue protection.
- ARA 290
- 4 mg SQ · daily
- BPC-157
- 250–500 mcg SQ · daily
- Frequency
- Once daily, same or separate injections
- Primary benefit
- Nerve regeneration, pain reduction, tissue healing
Follistatin-344
+ BPC-157
Multi-pathwayFollistatin-344 (myostatin antagonist) and BPC-157 (tissue repair peptide) address complementary pathways in muscle recovery. FST-344 promotes muscle protein synthesis by disinhibiting myostatin signaling, while BPC-157 accelerates healing of tendons, ligaments, and microtears via angiogenesis and collagen synthesis. Combined, they may support both hypertrophy and structural repair during high-volume training or injury recovery.
- Follistatin-344
- No approved protocol — endogenous modulation via resistance exercise + EAA
- BPC-157
- 250–500 mcg SQ · twice daily · near injury site or systemic
- Duration
- 4–8 weeks
- Primary benefit
- Muscle hypertrophy + accelerated soft tissue repair
+ TB-500
ModerateTB-500 (thymosin beta-4 fragment) promotes cell migration, angiogenesis, and anti-inflammatory signaling in muscle and connective tissue. Follistatin-344's anabolic signaling may synergize with TB-500's regenerative effects during muscle damage or overtraining, particularly in older adults where both myostatin inhibition and tissue repair are rate-limiting.
- Follistatin-344
- Endogenous upregulation (resistance training + protein)
- TB-500
- 2–5 mg SQ · twice weekly · loading phase 4 weeks, then maintenance
- Frequency
- Twice weekly TB-500, daily training stimulus for FST
- Primary benefit
- Enhanced recovery, reduced inflammation, muscle growth support