Bretisilocin

Bretisilocin, given by intravenous injection, produces threshold psychedelic effects at doses of 1mg and 3.3mg, has an optimal dose range of 10 to 15mg, and produces particularly intense effects at a dose of 20mg. Its duration is about 60 to 90minutes, whereas psilocybin has a duration of multiple hours and DMT has a duration of as short as 10minutes. The psychedelic effects of bretisilocin are generally resolved by approximately 2hours after administration, but have been found to last up to 4 to 6hours in some individuals. Peak effects occur about 10 to 20minutes following injection. and psychedelic subjective effects of bretisilocin at doses of 0.34 to 20mg by intravenous injection. The drug, administered intravenously in clinical studies, produces effects in humans including "altered states of consciousness, altered visual depth perception, abnormal thinking, euphoric mood, feeling drunk, feeling of body temperature changes, relaxation, sensory processing disorder (including intense visual effects with color changes), sensory overload, and time perception altered". The subjective effects of bretisilocin were described as very robust and consistent in strength with the effects of other psychedelics including LSD, DMT, and psilocybin as have been reported in clinical studies. In addition to intravenous administration, bretisilocin has been anecdotally reported to be active intranasally. ==Side effects==

Side effects of bretisilocin include acute sensory processing disorder, altered state of consciousness, abnormal thinking, euphoric mood, fatigue, and small increases in heart rate and blood pressure, among others. Adverse effects like fatigue and headache occur after the psychedelic experience and can persist for up to 24hours after administration. ==Interactions==

Pharmacodynamics Bretisilocin acts as a potent and well-balanced serotonin 5-HT2A and 5-HT2C receptor agonist, serotonin 5-HT2B receptor antagonist, and serotonin releasing agent. In another study however, it was a moderate-efficacy partial agonist of the serotonin 5-HT2B receptor. Its () values were 15.0–20.6nM (80.6–87.6%) at the serotonin 5-HT2A receptor and 9.5nM (85.1%) at the serotonin 5-HT2C receptor, whereas its at the serotonin 5-HT2B receptor was 5.8nM. It also induces more serotonin release than DMT, which may provide it with more entactogen-like qualities compared to DMT. Likewise, it produces anti-obsessional effects in the form of reduced marble burying in rodents. Bretisilocin does not produce conditioned place preference (CPP) in rodents, suggesting lack of reinforcing properties. Pharmacokinetics The pharmacokinetics of bretisilocin have been studied. The time to peak concentrations with intravenous injection is 10 to 20minutes. Its elimination half-life is approximately 45minutes (range 40 to 50minutes). ==Chemistry==

Bretisilocin, also known as 5-fluoro-N-methyl-N-ethyltryptamine, is a substituted tryptamine derivative. It is a derivative of dimethyltryptamine (DMT) and methylethyltryptamine (MET) as well as of 5-fluorotryptamine (5-FT). Synthesis The chemical synthesis of bretisilocin has been described. Analogues Some analogues of bretisilocin include 5-fluoro-DMT, 5-fluoro-DET, 5-fluoro-EPT, 5-chloro-DMT, 5-bromo-DMT, 5-fluoro-AMT, 5-fluoro-AET, 5-MeO-MET, and 7-F-5-MeO-MET, among others. ==History==

Bretisilocin was first described in 2021. It was patented by Andrew Kruegel at Gilgamesh Pharmaceuticals. The drug was encountered as a novel recreational designer drug in March 2026. ==Society and culture==

Names Bretisilocin is the generic name of the drug and its . It is also known by its developmental code name GM-2505. United States Bretislocin 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. ==Research==

Bretisilocin is under development as a potential pharmaceutical drug by Gilgamesh Pharmaceuticals. The drug has since been acquired from Gilgamesh Pharmaceuticals by AbbVie in a deal worth up to $1.2 billion. ==See also==