Side-by-side · Research reference

Follistatin-344vsGHRP-6

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-REVIEWED10/36 cited

Follistatin-344

Myostatin/Activin Antagonist · Research Use

15–25%FST/MSTN ratio ↑

344 AACirculating isoform

ResearchPhase status

Research · No approved protocol

GHRP-6

Hexapeptide GHRP · Strong appetite stimulant

100–200 mcgPer doseBowers 1990

Phase 1Evidence levelBowers 1990

~15 minHalf-lifeMalagón 1999

SQ · Multiple sites · 1–3×/day

01Mechanism of Action

Parameter

Follistatin-344

GHRP-6

Primary target

Myostatin (MSTN/GDF-8) and Activin A

Ghrelin receptor (GHS-R1a)Bowers 1990

Pathway

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

GHS-R1a → Gαq → Ca²⁺ → GH release; central appetite driveBowers 2002

Downstream effect

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

GH pulse + strong appetite stimulation; modest IGF-1 elevationBowers 2002

Feedback intact?

Yes — indirect antagonist, preserves endogenous regulation

—

Origin

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

Synthetic hexapeptide; first-generation GHRP from Bowers groupBowers 1990

Antibody development

Not documented in available trials (endogenous protein)

—

02Dosage Protocols

Parameter

Follistatin-344

GHRP-6

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 practiceBowers 1990

Half-life

Not established

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

~15 minMalagón 1999

Standard dose

—

100–200 mcg per injectionBowers 1990

Frequency

—

1–3× per day

Lower / starter dose

—

50 mcg per dose

Duration

—

8–12 weeks on / 4 off

Reconstitution

—

Bacteriostatic water

Timing

—

Pre-meal preferred for appetite support

03Metabolic / Fat Loss Evidence

Parameter

Follistatin-344

GHRP-6

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

GHRP-6

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

—

Pronounced — defining feature vs ipamorelin

Cortisol elevation

—

Mild

Prolactin elevation

—

Mild

Injection site reaction

—

Mild

Cancer risk

—

Contraindicated in active malignancy

Pregnancy / OB

—

Avoid

Absolute Contraindications

Follistatin-344

·Active malignancy
·No approved protocol — research use only

GHRP-6

·Active malignancy
·Pregnancy / breastfeeding

Relative Contraindications

Follistatin-344

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

GHRP-6

·Severe insulin resistance (appetite-driven caloric load)

05Administration Protocol

Parameter

Follistatin-344

GHRP-6

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.

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.

SQ — abdomen. Rotate sites.

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-meal for appetite support; pre-sleep for GH alignment.

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. Reconstituted: refrigerate ≤30 days.

5. Needle

—

29–31G, 4–8 mm insulin syringe.

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

GHRP-6

— no documented stacks