Disclaimer
CompoundIQ publishes research summaries for informational and educational purposes only. Nothing on this site constitutes medical advice, diagnosis, or treatment recommendations. Always consult a licensed healthcare provider. Many compounds listed are research chemicals not approved for human use.
FGL
Also known as: FG Loop peptide, NCAM-derived peptide, FGL peptide
FGL is a synthetic peptide derived from the second fibronectin type III module of neural cell adhesion molecule (NCAM). It corresponds to the FG loop region that interacts with fibroblast growth factor receptor 1 (FGFR1). Animal studies demonstrate cognitive enhancement, neuroprotection, and anti-inflammatory effects. Limited human data exists, with one small clinical trial in elderly subjects showing some cognitive improvements.
Risk Level
Medium RiskDifficulty
Advanced| Class | Peptide |
| Category | Underground Peptides |
Mechanism of Action
Binds and activates FGFR1, mimicking the heterophilic interaction between NCAM and FGFR1. This activates downstream signaling cascades including PLCgamma, PKC, and MAPK/ERK pathways, promoting synaptic plasticity, long-term potentiation, and neuronal survival. Also modulates microglial activation, reducing neuroinflammation.
Dosing Research
Clinical trial used subcutaneous injections in elderly subjects. Underground dosing is poorly characterized. Animal studies used 5-10 mg/kg intraperitoneally. No standardized human protocol exists. The peptide requires parenteral administration.
Side Effects & Risks
Limited human safety data. The clinical trial reported good tolerability. Theoretical risks include unwanted FGFR1 activation in non-neural tissues, which could potentially affect cell proliferation. Long-term effects of chronic FGFR1 stimulation are unknown.
Research Studies
Related compounds
Semaglutide
PeptideSemaglutide is a GLP-1 receptor agonist approved for type 2 diabetes (Ozempic) and chronic weight management (Wegovy). Clinical trials demonstrated average weight loss of 15-17% of body weight. It has become one of the most widely discussed medications in modern weight management.
Tirzepatide
PeptideTirzepatide is a dual GLP-1/GIP receptor agonist approved for type 2 diabetes (Mounjaro) and obesity (Zepbound). It has demonstrated unprecedented weight loss efficacy in clinical trials, with participants losing up to 20-25% of body weight. It represents the cutting edge of pharmaceutical weight management.
Liraglutide
PeptideLiraglutide is a GLP-1 receptor agonist approved for type 2 diabetes (Victoza, 1.8 mg) and obesity (Saxenda, 3.0 mg). It was the first GLP-1 agonist approved specifically for weight management. While effective, it has been largely superseded by semaglutide and tirzepatide in terms of weight loss efficacy.
PT-141
PeptidePT-141 (bremelanotide) is a synthetic cyclic heptapeptide melanocortin receptor agonist that was FDA-approved in 2019 as Vyleesi for the treatment of hypoactive sexual desire disorder in premenopausal women. Unlike PDE5 inhibitors, it acts centrally through the melanocortin system to increase sexual desire rather than just facilitating erection mechanics. It is the only FDA-approved on-demand treatment targeting central sexual arousal pathways.
Disclaimer
CompoundIQ publishes research summaries for informational and educational purposes only. Nothing on this site constitutes medical advice, diagnosis, or treatment recommendations. Always consult a licensed healthcare provider. Many compounds listed are research chemicals not approved for human use.