Side-by-side · Research reference
Follistatin-344vsIGF-DES
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-REVIEWED8/60 cited
Follistatin-344
Myostatin/Activin Antagonist · Research Use
15–25%FST/MSTN ratio ↑
344 AACirculating isoform
ResearchPhase status
Research · No approved protocol
IGF-DES
IGF-1 Analogue · Truncated N-Terminal
~10×Potency vs IGF-1
ReducedIGFBP binding
ResearchStatus
Injection (local or systemic) · Research protocols onlyBredehöft 2008
01Mechanism of Action
Parameter
Follistatin-344
IGF-DES
Pathway
FST-344 binds MSTN/Activin → prevents ActRIIB receptor engagement → disinhibits muscle anabolism
IGF1R activation → PI3K/Akt & MAPK signaling → protein synthesis, proliferation
Downstream effect
Elevated follistatin/myostatin ratio, increased muscle protein synthesis, attenuated muscle atrophy signalingJeong 2026
Enhanced muscle protein synthesis, myoblast differentiation, reduced apoptosis, cell proliferation
Feedback intact?
Yes — indirect antagonist, preserves endogenous regulation
Unknown — no human endocrine feedback data
Origin
Endogenous glycoprotein, 344-AA isoform lacking heparin-binding domain (vs FST-315)
Synthetic truncation of native IGF-1 — removal of N-terminal Gly-Pro-Glu tripeptideBredehöft 2008
Antibody development
Not documented in available trials (endogenous protein)
—
02Dosage Protocols
Parameter
Follistatin-344
IGF-DES
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 + in vitro only
Half-life
Not established
Circulating isoform; lacks tissue-binding domain of FST-315.
Shorter than IGF-1 due to reduced IGFBP binding
Rapid tissue uptake, limited systemic circulation.
Research dose range
—
10–100 ng/mL (in vitro); μg doses (animal models)
Highly context-dependent; no standardized human protocol.
Route
—
Subcutaneous or intramuscular (local injection favored)
Local delivery maximizes tissue-specific uptake.
Frequency
—
Variable — daily to multiple times daily in research
Human data
—
None — no clinical trials
03Metabolic / Fat Loss Evidence
Parameter
Follistatin-344
IGF-DES
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 mechanism
—
Indirect via muscle hypertrophy → metabolic rate elevation
Direct lipolysis
—
Minimal evidence — IGF-1 axis primarily anabolic, not lipolytic
Prostate model
—
Inhibited BPH cell proliferation when combined with vitamin D3 analogueCrescioli 2002
Context-specific anti-proliferative effect, not fat loss.
04Side Effects & Safety
Parameter
Follistatin-344
IGF-DES
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
—
Hypoglycemia risk
—
Theoretical — IGF-1 axis enhances glucose uptake
Mitogenic risk
—
Chronic IGF-1 receptor activation may promote cell proliferation, potential tumor growthCrescioli 2002
Injection site reaction
—
Expected — erythema, irritation, local swelling
Edema / Fluid retention
—
Possible via sodium retention (IGF-1 axis effect)
Human safety data
—
Absent — no human trials, all effects theoretical or extrapolated
Unknown long-term effects
—
No chronic dosing studies in humans; endocrine, metabolic consequences unknown
Absolute Contraindications
Follistatin-344
- ·Active malignancy
- ·No approved protocol — research use only
IGF-DES
- ·Active malignancy or history of cancer (mitogenic risk)
- ·Pregnancy / lactation (no safety data)
- ·Hypoglycemia disorders
Relative Contraindications
Follistatin-344
- ·Insulin resistance / Type 2 diabetes (monitor glucose)
- ·Pregnancy / lactation (unknown safety profile)
IGF-DES
- ·Diabetes mellitus (unpredictable glucose effects)
- ·Renal or hepatic impairment (clearance unknown)
- ·Edema-prone conditions (heart failure, nephrotic syndrome)
05Administration Protocol
Parameter
Follistatin-344
IGF-DES
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.
Des(1-3)IGF-1 has no approved human protocol. All administration details are derived from animal or in vitro research and should not be construed as medical guidance.
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.
Sterile water or bacteriostatic water per research protocol. Gently swirl; do not shake. Store reconstituted peptide at 2–8 °C.
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.
Subcutaneous (abdomen, thigh) or intramuscular (deltoid, vastus lateralis). Local injection to target tissue (e.g., muscle group) may enhance regional uptake.
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.
Frequency and timing vary by research design. Post-exercise or fasted state may theoretically enhance muscle uptake.
5. Needle gauge
—
27–31G insulin syringe for subcutaneous; 25–27G for intramuscular.
6. Monitoring
—
Glucose monitoring essential (hypoglycemia risk). No established IGF-1 or safety labs for human use.
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
IGF-DES
+ BPC-157
ModerateDes(1-3)IGF-1 promotes myoblast differentiation and protein synthesis, while BPC-157 enhances tissue repair, angiogenesis, and collagen synthesis. Both act on distinct pathways (IGF1R vs gastric pentadecapeptide mechanisms) to support muscle recovery and connective tissue integrity. Synergy is mechanistic but lacks direct co-administration studies.
- Des(1-3)IGF-1
- Research dose post-workout (local IM)
- BPC-157
- 250–500 mcg SQ, daily or twice daily
- Frequency
- Daily or per research protocol
- Primary benefit
- Accelerated muscle repair, enhanced hypertrophy, connective tissue support
+ TB-500
ModerateTB-500 (Thymosin Beta-4 fragment) promotes cell migration, angiogenesis, and wound healing via actin regulation. Des(1-3)IGF-1 drives protein synthesis and myoblast proliferation. Combined, these peptides may synergistically enhance muscle recovery, repair, and hypertrophy through complementary anabolic and regenerative pathways. No direct human co-administration data.
- Des(1-3)IGF-1
- Research dose post-workout (local IM)
- TB-500
- 2–5 mg SQ, 2× weekly
- Frequency
- Per research cycle
- Primary benefit
- Muscle hypertrophy, injury recovery, vascular support