The FGL peptide (a.k.a. FG loop peptide, or Fibroblast Growth Loop peptide) is 15 amino acids long and is synthetically derived from the neural cell adhesion molecule (NCAM) derived from the neural cell adhesion molecule (NCAM). NCAM is a glycoprotein that is found on the surface of nerve cells (neurons) and glial cells (protect neurons). NCAM activates FGL which in turn stimulates the production of new projections of developing neurons.

FGL also plays a role in the formation of synapses between neurons which results in improved synaptic plasticity and neuronal development. This in combination with enhanced synaptic transmission means FGL can help encode information, resulting in improved learning and memory. Add in neuronal cell protection and preservation and FGL becomes an important peptide with the potential to treat multiple conditions affecting cognitive function.