Side-by-side · Research reference
Follistatin-344vsMOTS-c
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-REVIEWED16/68 cited
Follistatin-344
Myostatin/Activin Antagonist · Research Use
15–25%FST/MSTN ratio ↑
344 AACirculating isoform
ResearchPhase status
Research · No approved protocol
MOTS-c
Mitokine · Mitochondria-Encoded
SQ · Variable · 2–3×/week
01Mechanism of Action
Parameter
Follistatin-344
MOTS-c
Primary target
Myostatin (MSTN/GDF-8) and Activin A
Mitochondrial 12S rRNA sORF → folate-AICAR-AMPK axisLee 2015
Pathway
FST-344 binds MSTN/Activin → prevents ActRIIB receptor engagement → disinhibits muscle anabolism
Downstream effect
Elevated follistatin/myostatin ratio, increased muscle protein synthesis, attenuated muscle atrophy signalingJeong 2026
Enhanced fatty acid oxidation, GLUT4-mediated glucose uptake, mitochondrial bioenergetics, anti-inflammationLee 2015
Feedback intact?
Yes — indirect antagonist, preserves endogenous regulation
Stress-responsive, AMPK-dependent nuclear translocationKim 2018
Origin
Endogenous glycoprotein, 344-AA isoform lacking heparin-binding domain (vs FST-315)
Endogenous 16-AA mitokine; mtDNA-encoded; declines with age; upregulated by exerciseReynolds 2021
Antibody development
Not documented in available trials (endogenous protein)
—
02Dosage Protocols
Parameter
Follistatin-344
MOTS-c
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 + anecdotalLee 2015Reynolds 2021A first-in-human phase 1 study 2021
Phase 1a/1b CB4211 analog trial completed 2021; no native MOTS-c RCT published.
Half-life
Not established
Circulating isoform; lacks tissue-binding domain of FST-315.
Minutes to hours (estimated)
Systemically unstable; native MOTS-c PK in humans not fully characterised.
Standard dose
—
5–10 mg / weekLee 2015
Experimental, extrapolated from animal data. No human RCT-derived dose.
Frequency
—
2–3× per week
Short half-life may necessitate more frequent dosing for saturation.
Lower / starter dose
—
2.5–5 mg / week
Recommended due to limited human data.
Duration
—
4–12 weeks (experimental)
Optimal cycle length unknown.
Reconstitution
—
Bacteriostatic water, 1–2 mL
10 mg/mL at 1 mL.
Timing
—
Pre-workout or fasted state preferred
Activity-context amplifies AMPK response.
03Metabolic / Fat Loss Evidence
Parameter
Follistatin-344
MOTS-c
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
—
Primary fat target
—
Diet-induced / metabolic obesity; systemic fat utilization
Quantified reduction
—
Significant HFD fat gain ↓Lee 2015
Murine models, dose-dependent (5 & 15 mg/kg).
IGF-1 impact
—
No direct IGF-1 pathway; AMPK-mediated
Effect on lean mass
—
High dose significantly ↑ lean mass in mice
Triglycerides
—
AMPK-driven FA oxidation suggests TG benefit (not directly measured)
Effect reversibility
—
Unknown — no long-term follow-up data
Key publication
—
Lee Cell Metab 2015 · Reynolds Nat Commun 2021 · Kim Cell Metab 2018Lee 2015Reynolds 2021Kim 2018
04Side Effects & Safety
Parameter
Follistatin-344
MOTS-c
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
—
Injection site reaction
—
Mild irritation (reported)
Fluid retention / Edema
—
Not reported
Cardiovascular
—
Heart palpitations (anecdotal); cardiac hypertrophy reversed in diabetic rats
Cancer risk
—
Contradictory data — some models suggest pro-proliferative effects
CNS / Neurological
—
Insomnia, headache (anecdotal reports)
GI symptoms
—
Nausea, stomach discomfort (reported)
Antibody formation
—
No data (no long-term human trials)
Pregnancy / OB
—
Avoid — insufficient safety data
Evidence quality
—
Phase 1 analog (CB4211); preclinical; anecdotal humanA first-in-human phase 1 study 2021
Absolute Contraindications
Follistatin-344
- ·Active malignancy
- ·No approved protocol — research use only
MOTS-c
- ·Pregnancy / breastfeeding (insufficient data)
Relative Contraindications
Follistatin-344
- ·Insulin resistance / Type 2 diabetes (monitor glucose)
- ·Pregnancy / lactation (unknown safety profile)
MOTS-c
- ·Active cancer or cancer predisposition
- ·AMPK pathway deficiency (efficacy nullified)
- ·Use with cancer-promoting medications (theoretical)
05Administration Protocol
Parameter
Follistatin-344
MOTS-c
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.
Add 1–2 mL bacteriostatic water. At 10 mg/vial, 1 mL gives 10 mg/mL concentration. Roll gently to dissolve.
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.
Subcutaneous — abdomen, thigh, or deltoid. Rotate sites to avoid lipohypertrophy. Pinch fat layer.
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.
Pre-workout or fasted state preferred — metabolic context amplifies AMPK response. 2–3× per week.
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: room temp, protected from light. Reconstituted: refrigerate, use within 21–30 days. Short systemic stability.
5. Needle
—
27–31G insulin syringe. Short needle (4–6 mm) for SQ delivery. Clean technique mandatory.
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
MOTS-c
+ Ipamorelin
ModerateMOTS-c activates AMPK/PGC-1α for mitochondrial efficiency and fatty acid oxidation; ipamorelin stimulates GH for anabolic recovery and sleep depth. Pathways are complementary — MOTS-c handles metabolic flexibility and glucose handling while ipamorelin drives recovery and body recomposition through GH. Theoretical synergy is high; clinical data is lacking.
- MOTS-c
- 5 mg SQ · pre-workout (2–3×/wk)
- Ipamorelin
- 200–300 mcg SQ · pre-sleep (daily)
- Primary benefit
- Metabolic flexibility + GH recovery + ROS reduction