Side-by-side · Research reference
Follistatin-344vsHumanin
Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.
AHuman-MechanisticHUMAN-REVIEWED4/58 cited
BAnimal-StrongHUMAN-REVIEWED14/52 cited
Follistatin-344
Myostatin/Activin Antagonist · Research Use
15–25%FST/MSTN ratio ↑
344 AACirculating isoform
ResearchPhase status
Research · No approved protocol
Humanin
Mitochondrial-Derived Peptide · Cytoprotective
SQ · Experimental
01Mechanism of Action
Parameter
Follistatin-344
Humanin
Primary target
Myostatin (MSTN/GDF-8) and Activin A
Pathway
FST-344 binds MSTN/Activin → prevents ActRIIB receptor engagement → disinhibits muscle anabolism
Humanin binds Bax/Bim → inhibits mitochondrial outer membrane permeabilization (MOMP) → blocks cytochrome c release → prevents caspase activation → cell survival
Downstream effect
Elevated follistatin/myostatin ratio, increased muscle protein synthesis, attenuated muscle atrophy signalingJeong 2026
Suppression of apoptosis, mitochondrial stabilization, reduced oxidative stress, preservation of germ cells and neurons under stressZhu 2022Lue 2021Velentza 2024
Feedback intact?
Yes — indirect antagonist, preserves endogenous regulation
Not applicable — peptide acts as anti-apoptotic signal, not hormonal axis
Origin
Endogenous glycoprotein, 344-AA isoform lacking heparin-binding domain (vs FST-315)
Encoded by short open reading frame in mitochondrial 16S rRNA gene (MTRNR2). 24-28 amino acids. 13 homologous variants (MTRNR2L1-L13) identified.Zhu 2022Shahzaib 2026
Antibody development
Not documented in available trials (endogenous protein)
Not reported in animal models
02Dosage Protocols
Parameter
Follistatin-344
Humanin
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).
—
Evidence basis
Human observational / biomarker studies
Animal models (rat, mouse)Huang 2025El 2022Velentza 2024
Half-life
Not established
Circulating isoform; lacks tissue-binding domain of FST-315.
—
Standard experimental dose (HNG)
—
4 mg/kg IP (rat)
Most common dose in rodent models.
Ex vivo bone culture
—
1 µg/mL
Protective against venetoclax-induced bone growth retardation.
Frequency
—
Daily (IP)
Duration
—
8–12 weeks in animal studies
Human data
—
None — no clinical trials reported
Analog (HNG)
—
Gly[14]-humanin — more potent variant
Substitution at position 14 enhances cytoprotective activity.
03Metabolic / Fat Loss Evidence
Parameter
Follistatin-344
Humanin
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
—
Direct fat loss evidence
—
None
Mechanism overlap
—
Mitochondrial health may indirectly influence metabolic efficiency, but no quantified effect
04Side Effects & Safety
Parameter
Follistatin-344
Humanin
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
—
Animal model safety
—
Well-tolerated in rat and mouse studies at 4 mg/kg for 8–12 weeks
Human safety data
—
None — no clinical trials
Theoretical fibrillation risk
—
Induces amyloid-like fibrillation of Bax/BID. Long-term sequelae unknown.
Injection site reaction
—
Not reported in animal studies (IP route)
Reproductive safety
—
Protective in POI model (cyclophosphamide-induced), no adverse effects on fertility notedHuang 2025
Absolute Contraindications
Follistatin-344
- ·Active malignancy
- ·No approved protocol — research use only
Humanin
- ·Unknown — no human data
Relative Contraindications
Follistatin-344
- ·Insulin resistance / Type 2 diabetes (monitor glucose)
- ·Pregnancy / lactation (unknown safety profile)
Humanin
- ·Active malignancy (theoretical risk of anti-apoptotic effect on tumour cells)
05Administration Protocol
Parameter
Follistatin-344
Humanin
1. Regulatory status
Follistatin-344 is not approved for human administration. All cited studies measure endogenous serum follistatin as a biomarker, not as an exogenous therapeutic agent.
Intraperitoneal (IP) in animal models. Subcutaneous route untested. No human protocols exist.
2. Endogenous modulation
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.
Synthetic peptide reconstituted in sterile saline or PBS. No commercial formulation available.
3. Measurement context
Serum follistatin and follistatin/myostatin ratio are used diagnostically in sarcopenia screening and as biomarkers of muscle anabolic balance in clinical trials.
Daily administration in animal studies. Optimal timing not characterized.
4. Research consideration
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.
Lyophilised powder: -20 °C. Reconstituted: 4 °C, use within 7 days. Avoid freeze-thaw cycles.
5. Human use
—
No FDA approval, no IND, no clinical trials. Experimental research tool only.
06Stack Synergy
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
Humanin
+ MOTS-c
Multi-pathwayBoth are mitochondrial-derived peptides. MOTS-c enhances metabolic efficiency and insulin sensitivity via AMPK activation, while humanin prevents mitochondrial apoptosis. Combined, they address mitochondrial function (MOTS-c) and survival signaling (humanin), supporting cellular resilience under metabolic and oxidative stress.
- Humanin
- 4 mg/kg IP · daily (animal model)
- MOTS-c
- 5 mg/kg IP · daily (animal model)
- Frequency
- Once daily
- Primary benefit
- Mitochondrial health, metabolic efficiency, anti-apoptotic signaling