2C-B-FLY is the dihydrodifuran analog of the Schedule I hallucinogen 4-bromo-2,5-dimethoxyphenethylamine (2C-B). It acts as a partial agonist at the 5-HT2A serotonin receptor and demonstrates high binding affinity for the 5-HT2B and 5-HT2C serotonin receptors.