Side-by-side · Research reference

Follistatin-344vsMelanotan-II

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-REVIEWED9/43 cited

Follistatin-344

Myostatin/Activin Antagonist · Research Use

15–25%FST/MSTN ratio ↑

344 AACirculating isoform

ResearchPhase status

Research · No approved protocol

Melanotan-II

MC1R + MC4R agonist · Tanning + sexual response

0.25–1.0 mgPer doseDorr 1996

Phase 1Evidence levelDorr 1996

~1 hrHalf-life

SQ · Abdomen · Loading 5–7 days, then maintenance

01Mechanism of Action

Parameter

Follistatin-344

Melanotan-II

Primary target

Myostatin (MSTN/GDF-8) and Activin A

MC1R (skin) + MC3R + MC4R (CNS sexual / appetite)Dorr 1996

Pathway

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

MC1R agonism → melanocyte tyrosinase → eumelanin synthesis. MC4R → autonomic sexual arousal centresDorr 1996 Simerly 2023

Downstream effect

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

Skin darkening, photo-protection, increased sexual desire / spontaneous erectionDorr 1996

Feedback intact?

Yes — indirect antagonist, preserves endogenous regulation

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Origin

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

Cyclic 7-AA modified α-MSH analog; designed at University of ArizonaDorr 1996

Antibody development

Not documented in available trials (endogenous protein)

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02Dosage Protocols

Parameter

Follistatin-344

Melanotan-II

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 + anecdotalDorr 1996

Half-life

Not established

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

~1 hour plasma; effects on melanocytes persist days

Loading phase

—

0.25–0.5 mg/day SQ × 5–7 daysDorr 1996

Builds up to visible tan.

Maintenance

—

0.5–1.0 mg 1–2×/week

After visible tan develops; supports with UV exposure.

Frequency

—

Daily during loading; 1–2× per week maintenance

Lower / starter dose

—

0.1 mg / day

Conservative starter — assess tolerability for nausea.

Duration

—

8–12 weeks per cycle

Reconstitution

—

Bacteriostatic water; protect from light

Timing

—

Evening preferred (24h tan-development cycle)

03Metabolic / Fat Loss Evidence

Parameter

Follistatin-344

Melanotan-II

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

Melanotan-II

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

—

Nausea

—

Common, especially loading phase

Flushing

—

Common transient

Spontaneous erection

—

Common in men — MC4R cross-effectDorr 1996

Increased mole / freckle pigmentation

—

Existing moles darken; new lesions possible

Melanoma risk

—

Theoretical concern — increased melanocyte activity; CAUTION in melanoma history

Appetite suppression

—

MC4R-mediated; mild

Pregnancy / OB

—

Contraindicated

Absolute Contraindications

Follistatin-344

·Active malignancy
·No approved protocol — research use only

Melanotan-II

·History of melanoma or atypical mole syndrome
·Pregnancy / breastfeeding
·Active uncontrolled hypertension

Relative Contraindications

Follistatin-344

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

Melanotan-II

·Significant freckling / dysplastic nevus
·Personal or family melanoma history

05Administration Protocol

Parameter

Follistatin-344

Melanotan-II

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 10 mg vial → 5 mg/mL = 500 mcg per 0.1 mL. Light-protected.

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.

Evening preferred. UV exposure (sunlight or tanning bed) helps develop tan.

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: refrigerate, light-protected. Reconstituted: refrigerate ≤30 days.

5. Needle

—

29–31G 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

Melanotan-II

— no documented stacks