2C-B-FLY
2C-B-FLY is a benzodifuran ('FLY') analogue of 2C-B, with the methoxy groups locked into fused furan rings. It is a longer-acting psychedelic that has been implicated in fatalities, often through confusion with the far more toxic Bromo-DragonFLY.
01 Overview
2C-B-FLY rigidifies the 2C-B scaffold into a dihydrodifuran ('fly') structure, increasing 5-HT2A affinity and lengthening duration. It emerged as a research chemical in the 2000s and gained a dangerous reputation partly through mislabelling and cross-confusion with Bromo-DragonFLY.
Several deaths have been linked to FLY-class compounds, and its long duration compounds the danger of dosing errors. No controlled human studies exist.
02 Mechanism
Potent 5-HT2A partial agonist; the fused furan rings lock the methoxy oxygens in a conformation favouring receptor binding, raising potency and duration.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Threshold | 2–5 mg | Oral | |
| Common | 8–16 mg | Oral | Long duration; dose confusion with Bromo-DragonFLY has been fatal. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Warm visual psychedeliaColourful visuals and body warmth, often described as 2C-B-like but longer. | strong | Anecdotal | |
| Emotional opennessEmpathogenic, sociable tone in favourable reports. | moderate | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| VasoconstrictionFLY-class compounds are potent vasoconstrictors; prolonged ischaemia has caused limb injury in related agents. | Severe | Common | Anecdotal | |
| Fatal misidentificationConfusion with the far more potent Bromo-DragonFLY has caused deaths. | Life-threatening | Uncommon | Anecdotal |