FGL, sometimes called FGLL, is a peptide that mimics part of the neural cell adhesion molecule, a protein involved in how neurons connect and communicate. It was developed by the Danish company Enkam Pharmaceuticals as a candidate for cognitive impairment and neuroprotection, and the preclinical work suggested it could promote synaptic plasticity. It reached early human testing at most and no completed controlled trial is verifiable. The company did not carry it to approval and no programme survives. It sits in the large category of neuroprotective candidates with encouraging animal data that quietly stalled, and the animal data continues to be cited as though the stall had not happened.