Side-by-side · Research reference

Follistatin-344vsGlutathione

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

BHuman-MechanisticHUMAN-REVIEWED6/39 cited

Follistatin-344

Myostatin/Activin Antagonist · Research Use

15–25%FST/MSTN ratio ↑

344 AACirculating isoform

ResearchPhase status

Research · No approved protocol

Glutathione

Endogenous Tripeptide · Antioxidant

γ-Glu-Cys-GlyStructure

UbiquitousTissue distribution

GCL + GSBiosynthesisWang 2026 Aiana 2026

IV · Oral · Inhaled

01Mechanism of Action

Parameter

Follistatin-344

Glutathione

Primary target

Myostatin (MSTN/GDF-8) and Activin A

Intracellular redox systems, glutathione peroxidase, glutathione transferase

Pathway

FST-344 binds MSTN/Activin → prevents ActRIIB receptor engagement → disinhibits muscle anabolism

Synthesized via glutamate-cysteine ligase (GCL) → γ-glutamylcysteine → glutathione synthetase (GS) → GSH

Downstream effect

Elevated follistatin/myostatin ratio, increased muscle protein synthesis, attenuated muscle atrophy signalingJeong 2026

Reduction of reactive oxygen species, conjugation of electrophiles, maintenance of cellular thiol-disulfide balance, GPX4 activation for lipid peroxide reduction

Feedback intact?

Yes — indirect antagonist, preserves endogenous regulation

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Origin

Endogenous glycoprotein, 344-AA isoform lacking heparin-binding domain (vs FST-315)

Endogenous tripeptide; predominantly synthesized in liver, exported to extracellular space and tissuesTerrell 2025 Hecht 2026

Antibody development

Not documented in available trials (endogenous protein)

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02Dosage Protocols

Parameter

Follistatin-344

Glutathione

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).

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Evidence basis

Human observational / biomarker studies

Animal mechanistic + human mechanistic

Half-life

Not established

Circulating isoform; lacks tissue-binding domain of FST-315.

—

Endogenous synthesis

—

Hepatic synthesis ~10 g/day (basal rate)

Tissue-specific; demand-driven upregulation via Nrf2 signaling.

Exogenous oral

—

250–1000 mg/day

Bioavailability limited; gastric hydrolysis reduces systemic uptake.

IV supplementation

—

600–1200 mg (research protocols)

Used in clinical oxidative stress and hepatic detoxification studies.

Precursor strategy

—

N-acetylcysteine (NAC) 600–1200 mg/day

Provides cysteine for endogenous GSH synthesis; bypasses GI degradation.

03Metabolic / Fat Loss Evidence

Parameter

Follistatin-344

Glutathione

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.

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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

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04Side Effects & Safety

Parameter

Follistatin-344

Glutathione

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)

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Regulatory status

Not approved for human use — research peptide only

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Oral supplementation

—

GI discomfort, bloating (mild, dose-dependent)

IV administration

—

Rare hypersensitivity, infusion site reaction

Inhalation

—

Bronchospasm risk in asthma (rare)

Tumor metabolism

—

Extracellular GSH catabolism supplies cysteine to tumors; theoretical concern in active malignancyHecht 2026

Absolute Contraindications

Follistatin-344

·Active malignancy
·No approved protocol — research use only

Glutathione

—

Relative Contraindications

Follistatin-344

·Insulin resistance / Type 2 diabetes (monitor glucose)
·Pregnancy / lactation (unknown safety profile)

Glutathione

·Active malignancy (theoretical cysteine supply risk)Hecht 2026
·Severe asthma (inhaled formulations)

05Administration Protocol

Parameter

Follistatin-344

Glutathione

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.

Capsule or liquid form, 250–1000 mg once daily. Take on empty stomach for improved absorption, though GI hydrolysis limits bioavailability. NAC precursor strategy often preferred.

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.

Clinical protocols: 600–1200 mg slow infusion over 30–60 minutes. Used for acute oxidative stress, hepatic detoxification support. Administered in medical settings.

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.

Nebulized GSH (research protocols). Monitor for bronchospasm in reactive airway patients. Used experimentally for pulmonary oxidative stress.

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.

N-acetylcysteine (NAC) 600–1200 mg/day PO. Provides cysteine substrate for endogenous GSH synthesis. Bypasses gastric degradation, preferred for chronic supplementation.

06Stack Synergy

Follistatin-344

+ BPC-157

Multi-pathway

View BPC-157 →

Follistatin-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

Moderate

View TB-500 →

TB-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

Glutathione

— no documented stacks