Side-by-side · Research reference
Follistatin-344vsIpamorelin
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
BPhase 1HUMAN-REVIEWED21/57 cited
Follistatin-344
Myostatin/Activin Antagonist · Research Use
15–25%FST/MSTN ratio ↑
344 AACirculating isoform
ResearchPhase status
Research · No approved protocol
Ipamorelin
Selective GHRP · Ghrelin Mimetic
SQ · Multiple sites · 1–3×/day
01Mechanism of Action
Parameter
Follistatin-344
Ipamorelin
Primary target
Myostatin (MSTN/GDF-8) and Activin A
Ghrelin receptor (GHS-R1a) on anterior pituitaryRaun 1998
Pathway
FST-344 binds MSTN/Activin → prevents ActRIIB receptor engagement → disinhibits muscle anabolism
GHS-R1a binding → Gαq/11 → ↑intracellular Ca²⁺ → GH vesicle exocytosisRaun 1998Bowers 1991
Downstream effect
Elevated follistatin/myostatin ratio, increased muscle protein synthesis, attenuated muscle atrophy signalingJeong 2026
GH pulse amplification, IGF-1 elevation, recovery and lipolytic effectsBowers 2002
Feedback intact?
Yes — indirect antagonist, preserves endogenous regulation
Yes — pulsatile pattern preserved; somatostatin feedback activeBowers 2002
Origin
Endogenous glycoprotein, 344-AA isoform lacking heparin-binding domain (vs FST-315)
Pentapeptide H-Aib-His-D-2-Nal-D-Phe-Lys-NH₂; rationally designed for ghrelin-receptor selectivityRaun 1998
Antibody development
Not documented in available trials (endogenous protein)
Not reported in short-term studies
02Dosage Protocols
Parameter
Follistatin-344
Ipamorelin
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
Phase 1 + clinical practiceRaun 1998Sigalos 2018
Half-life
Not established
Circulating isoform; lacks tissue-binding domain of FST-315.
~2 hoursRaun 1998
Longer than GHRP-6 (15 min); shorter than CJC-1295-DAC (~8 days).
Standard dose
—
200–300 mcg per injectionRaun 1998
Anecdotal community range; clinical doses 1–3 mg IV in trials.
Frequency
—
1–3× per day
Once daily pre-sleep is most common; twice or thrice for advanced users.
Lower / starter dose
—
100 mcg per dose
Duration
—
8–12 weeks on / 4 weeks off (anecdotal)
GHS-R desensitisation reported with continuous dosing.
Reconstitution
—
Bacteriostatic water; typical 2 mL per 5 mg vial
Timing
—
Pre-sleep + fasted preferred; 30 min away from food
03Metabolic / Fat Loss Evidence
Parameter
Follistatin-344
Ipamorelin
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
—
04Side Effects & Safety
Parameter
Follistatin-344
Ipamorelin
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
—
Hunger
—
Mild appetite increase via ghrelin-receptor crosstalk
Injection site reaction
—
Mild irritation possible
GH excess (overdose)
—
Joint pain, edema, insulin resistance
IGF-1 elevation
—
Dose-dependent; monitor with chronic high-dose use
Cancer risk
—
Theoretical via GH/IGF-1 axis; contraindicated in active malignancy
Pregnancy / OB
—
Avoid
Absolute Contraindications
Follistatin-344
- ·Active malignancy
- ·No approved protocol — research use only
Ipamorelin
- ·Active malignancy or cancer history
- ·Pregnancy / breastfeeding
- ·Disrupted hypothalamic-pituitary axis
Relative Contraindications
Follistatin-344
- ·Insulin resistance / Type 2 diabetes (monitor glucose)
- ·Pregnancy / lactation (unknown safety profile)
Ipamorelin
- ·Untreated diabetes
- ·Severe insulin resistance
- ·Concurrent corticosteroid use (theoretical desensitisation)
05Administration Protocol
Parameter
Follistatin-344
Ipamorelin
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 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL. Roll gently. 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 or thigh. Rotate sites. Pinch fat for shallow SQ delivery.
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-sleep optimal — aligns with natural GH pulse. Some protocols add a morning fasted dose.
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 2–8 °C, use within 30 days.
5. Needle
—
29–31G, 4–8 mm insulin syringe.
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
Ipamorelin
+ Tesamorelin
StrongIpamorelin (GHRP) + tesamorelin (GHRH analogue) is the textbook dual-axis GH stack. They activate two distinct pituitary receptors — the ghrelin receptor and the GHRH receptor — producing a synergistic GH pulse larger than either alone. Ipamorelin's selectivity (no cortisol/prolactin spike) makes it the ideal GHRP partner for long-term protocols.
- Ipamorelin
- 200–300 mcg SQ · pre-sleep
- Tesamorelin
- 2 mg SQ · same injection · pre-sleep
- Primary benefit
- Maximal GH pulsatility, fat loss, recovery, sleep depth
+ CJC-1295 (no DAC)
StrongCJC-1295 (no DAC) is a short-acting GHRH analogue. Combined with ipamorelin (GHRP), the pulse is amplified across both receptor systems with timing similar to native physiology. Without the DAC modification, the stack maintains sharp peaks rather than the sustained elevation seen with CJC-1295-DAC + ipamorelin.
- Ipamorelin
- 200–300 mcg SQ · pre-sleep
- CJC-1295 (no DAC)
- 100 mcg SQ · same injection
- Primary benefit
- Pulsatile GH stimulation matching physiological pattern