What is 25I-NBOMe?
25I-NBOMe (2C-I-NBOMe, Cimbi-5, also shortened to “25I”) is a synthetic hallucinogen that is used in biochemistry research for mapping the brain’s usage of the type 2A serotonin receptor; it is also sometimes used for recreational purposes. A derivative of the substituted phenethylamine 2C-I family, it is the most well-known member of the 25-NB family. It was discovered in 2003 by chemist Ralf Heim at the Free University of Berlin, who published his findings in his PhD dissertation. The compound was subsequently investigated by a team at Purdue University led by David Nichols.
The carbon-11 labelled version of 25I-NBOMe, [11C]Cimbi-5, was synthesized and validated as a radiotracer for positron emission tomography (PET) in Copenhagen. Being the first 5-HT2A receptor full agonist PET radioligand, [11C]-CIMBI-5 shows promise as a more functional marker of these receptors, particularly in their high affinity states.
25I-NBOMe is potent, being active in sub-milligram doses. A common dose of the hydrochloride salt is 600–1,200 µg. The UK Advisory Council on the Misuse of Drugs states that a common dose is between 50 and 100 µg, although other sources indicate that these figures are incorrect; Erowid tentatively suggests that the threshold dosage for humans is 50–250 µg, with a light dose between 200–600 µg, a common dose at 500–800 µg, and a strong dose at 700–1500 µg. At this level of potency, it is not possible to accurately measure a single dose of 25I-NBOMe powder without an analytical balance, and attempting to do so may put the user at significant risk of overdose.
Effects of 25I-NBOMe
25I-NBOMe effects usually last 6–10 hours if taken sublingually or buccally (top of tongue). When it is ingested, effects usually last 4–6 hours. However, effects can last significantly longer depending on dosage; durations longer than 12 hours have been reported.
25I-NBOMe can also be vaporized and inhaled, this may cause significantly quicker effects and shorter duration as is expected from that route of administration. However, this route of administration is very dangerous, unless using precise liquid measurement, due to the difficulties of measuring and handling substances active in the microgram range.
25I-NBOMe has similar effects to LSD, though users report more negative effects while under the influence and more risk of harm following use as compared to the classical psychedelics.