Mescaline-FLY, also known as flyscaline, M-FLY, or MeO-2C-2,6-IFLY, is a putatively non-hallucinogenic serotonin receptor modulator of the phenethylamine, scaline, and FLY families. It is the FLY (benzodifuran) analogue of the psychedelic drug mescaline.
Mescaline-FLY is not known to have been tested in humans, and hence it is unknown whether it produces psychedelic effects in humans. However, based on its lack of psychedelic-like effects in animals, it may not be expected to be hallucinogenic in humans.
Mescaline-FLY shows affinity for the serotonin 5-HT<sub>2</sub> receptors. Its affinities (K<sub>i</sub>) were 335 to 4,443nM for the serotonin 5-HT<sub>2A</sub> receptor, 205 to 302nM for the serotonin 5-HT<sub>2B</sub> receptor, and 61.5 to 654nM for the serotonin 5-HT<sub>2C</sub> receptor. The affinity of mescaline-FLY for the serotonin 5-HT<sub>2A</sub> receptor was only slightly higher than that of mescaline, whereas it showed several-fold higher affinity for the serotonin 5-HT<sub>2C</sub> receptor and about 2-fold higher affinity for the serotonin 5-HT<sub>2B</sub> receptor compared to mescaline. In a subsequent study, at the serotonin 5-HT<sub>2A</sub> receptor, its affinity (K<sub>0.5</sub>) was 243nM and its () was 3,470nM (57%), relative to respective values for mescaline of 801nM and 2,700nM (88%). Hence, whereas mescaline is a full agonist of the serotonin 5-HT<sub>2A</sub> receptor, mescaline-FLY is a moderate-efficacy partial agonist of the receptor.
The drug failed to substitute for LSD in rodent drug discrimination tests, producing a maximum substitution of 29% at a dose of 55.2ümol/kg, whereas mescaline fully substituted for LSD with an of 33.5ümol/kg. The lack of substitution with mescaline-FLY is in notable contrast to findings with other FLY drugs, such as 2C-B-FLY, DOB-FLY, and Bromo-DragonFLY.
Mescaline-FLY was first described in the scientific literature by the lab of David E. Nichols and colleagues by 1995.
Mescaline-FLY is not a controlled substance in Canada as of 2025.
Mescaline-FLY is not an explicitly controlled substance in the United States. However, it could be considered a controlled substance under the Federal Analogue Act if intended for human consumption.