FGL vs Semax
Limited Research vs Well Studied
synergistic Both support neuroplasticity and neuroprotection through complementary mechanisms -- FGFR1 activation (FGL) and BDNF upregulation (Semax).
Molecular Data
FGL Semax
Weight ~1500 Da 813.93 Da
Half-life Not well characterized 0.5-2 hours
Chain — 7 amino acids
Type Synthetic peptide derived from the second fibronectin type III module of NCAM ACTH(4-10) synthetic analog
Key Benefits
FGL
01 Activates FGFR1 to promote synaptic plasticity
02 Stimulates hippocampal neurogenesis
03 Provides neuroprotection against excitotoxic and ischemic injury
04 Enhances long-term potentiation (LTP) in preclinical models
05 Potential cognitive enhancement via NCAM-mimetic signaling
Semax
01 Rapid brain delivery via intranasal route
02 Rapidly increases BDNF levels
03 Extensive clinical research in Russia
04 Easy self-administration
05 Modulates dopamine and serotonin systems
06 Neuroprotective effects
Dosing Protocols
FGL
100-200mcg per day / 1x daily
Cognitive support (research protocol) 100-200mcg 1x daily
Semax
300-600mcg per dose (up to 1000mcg for intensive use) / 1-2x daily (morning recommended for cognitive boost)
Research protocol 500-750mcg 1x daily
Intensive protocol 750-1000mcg 1-2x daily
Side Effects
FGL
Injection site reactions (redness, mild swelling, irritation)
Semax
Mild nasal discomfort (nasal route)
Possible nasal sensation upon administration
Contraindications
Pregnancy or breastfeeding
Known peptide or NCAM-related compound allergies
Very limited human safety data -- use with caution under medical supervision
Pregnancy or breastfeeding
Known peptide allergies
Do not exceed 4-week continuous use without medical supervision
Research Evidence
FGL Semax
Status Limited Research Well Studied
References 4 studies 5 studies
Latest — 2025
FDA Approved No No
This comparison is for educational and research purposes only. Consult a healthcare professional before use.