Side-by-side · Research reference
Follistatin-344vsTesamorelin
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
BFDA-ApprovedFlagship27/68 cited
Follistatin-344
Myostatin/Activin Antagonist · Research Use
15–25%FST/MSTN ratio ↑
344 AACirculating isoform
ResearchPhase status
Research · No approved protocol
Tesamorelin
GHRH Analogue · FDA-Approved
SQ · Abdomen · Once Daily
01Mechanism of Action
Parameter
Follistatin-344
Tesamorelin
Primary target
Myostatin (MSTN/GDF-8) and Activin A
Hypothalamic GHRH receptorsEGRIFTA® (tesamorelin for inje 2010
Pathway
FST-344 binds MSTN/Activin → prevents ActRIIB receptor engagement → disinhibits muscle anabolism
GHRH → Pituitary GH release → Liver IGF-1 synthesisFalutz 2007
Downstream effect
Elevated follistatin/myostatin ratio, increased muscle protein synthesis, attenuated muscle atrophy signalingJeong 2026
Increased GH pulsatility, elevated IGF-1, lipolysis of visceral adipose tissueFalutz 2010
Feedback intact?
Yes — indirect antagonist, preserves endogenous regulation
Yes — physiological pulsatility preserved
Origin
Endogenous glycoprotein, 344-AA isoform lacking heparin-binding domain (vs FST-315)
Synthetic 44-AA GHRH analogue with trans-3-hexenoic-acid modification for stabilityEGRIFTA® (tesamorelin for inje 2010
Antibody development
Not documented in available trials (endogenous protein)
~50% after 26 wks (non-neutralising in most)Sévigny 2018
02Dosage Protocols
Parameter
Follistatin-344
Tesamorelin
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.
~26 min (plasma)EGRIFTA® (tesamorelin for inje 2010
Modified vs native GHRH (7 min t½).
Frequency
—
Once daily (morning or pre-sleep)
Aligns with natural GH pulse.
Duration
—
12–52 weeks
VAT returns within months of stopping.
Reconstitution
—
Sterile water per labeling
Preserved at 2–8 °C after reconstitution.
Timing
—
Empty stomach, pre-sleep preferred
03Metabolic / Fat Loss Evidence
Parameter
Follistatin-344
Tesamorelin
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
—
Visceral adipose tissue (VAT) — abdominal
Effect on lean mass
—
Modest lean mass preservation / slight increase
Effect reversibility
—
VAT returns within months of stopping
Key publication
—
Falutz et al. NEJM 2007 · Falutz JCEM 2010 · FDA approval 2010Falutz 2007Falutz 2010EGRIFTA® (tesamorelin for inje 2010
04Side Effects & Safety
Parameter
Follistatin-344
Tesamorelin
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
—
Erythema, pruritus, redness (common)
Fluid retention / Edema
—
Peripheral edema, arthralgia, carpal tunnel (GH-axis effect)
IGF-1 elevation
—
Dose-dependent; supraphysiological levels = discontinue
Cancer risk
—
Contraindicated in active malignancy (GH/IGF-1 axis); theoretical tumour growth riskEGRIFTA® (tesamorelin for inje 2010
Antibody formation
—
~50% at 26 weeks; non-neutralising in most; rare hypersensitivity (<1%)Sévigny 2018
GI symptoms
—
Nausea, diarrhea (mild, transient)
Absolute Contraindications
Follistatin-344
- ·Active malignancy
- ·No approved protocol — research use only
Tesamorelin
- ·Active malignancy or history of treated cancer
- ·Pregnancy
- ·Hypersensitivity to tesamorelin or mannitol
- ·Disruption of hypothalamic-pituitary axis (trauma, tumour, radiation)
Relative Contraindications
Follistatin-344
- ·Insulin resistance / Type 2 diabetes (monitor glucose)
- ·Pregnancy / lactation (unknown safety profile)
Tesamorelin
- ·Untreated diabetes (monitor HbA1c)
- ·Severe carpal tunnel syndrome
- ·Acute critical illness
05Administration Protocol
Parameter
Follistatin-344
Tesamorelin
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 2.1 mL sterile water to 2 mg lyophilised vial. Roll gently — do not shake. Solution should be clear.
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 preferred. Rotate sites (avoid same spot within 2 cm). Avoid navel and waistband area.
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.
Once daily. Preferred: evening, 2–3 hrs post-meal, before sleep — aligns with natural GH secretion pulse.
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, light-protected. Reconstituted: refrigerate 2–8 °C, use within 21 days.
5. Needle
—
27–31G, 4–8 mm insulin syringe. Pinch skin, 45° angle for lean individuals.
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
Tesamorelin
+ Ipamorelin
StrongTesamorelin (GHRH analogue) and ipamorelin (GHRP / ghrelin mimetic) act on two distinct receptor systems to amplify GH release synergistically — GHRH receptor + ghrelin receptor. This dual-axis stimulation produces a more robust, sustained GH pulse than either alone while maintaining physiological pulsatility. Ipamorelin is highly selective with minimal cortisol or prolactin elevation, making it the preferred GHRP pairing.
- Tesamorelin
- 2 mg SQ · evening
- Ipamorelin
- 200–300 mcg SQ · same injection
- Frequency
- Once daily, pre-sleep
- Primary benefit
- Maximal GH pulsatility, fat loss, recovery, sleep quality