25i (25I‑NBOMe) is a synthetic hallucinogenic drug in the NBOMe family that is sometimes misrepresented and sold as LSD or other psychedelics. (Source) It was first synthesized in 2003 by a researcher at the Free University of Berlin as part of scientific work on serotonin receptors, not for human use. (Source)

25i is considered a designer drug because it was created in a laboratory to mimic and intensify the effects of classic hallucinogens like LSD and mescaline. (Source) After its chemistry was published, underground labs began producing it illegally and distributing it worldwide through street dealers and online markets.

Compared with many other illegal drugs, 25i is relatively inexpensive per dose, which can make it especially appealing to teens and young adults. (Source) However, the low price hides an extremely high risk: the active dose is measured in micrograms, so a very small error in dosing can lead to seizures, organ failure, or death.

Like fentanyl, 25i can be active in very small amounts, and there have been reports of toxicity from accidental exposure to powders or liquids. (Source) Because of its high risk of serious harm and lack of accepted medical use, 25I‑NBOMe is classified as a Schedule I controlled substance in the United States. (Source)

Using 25i even once can result in a medical emergency, long‑term psychological problems, or fatal overdose, especially when the person believes they are taking LSD and is unaware of the drug’s true potency. (Source)