2,5-Dimethoxy-4-isobutylamphetamine (DOIB or DOiBu) is a serotonin 5-HT<sub>2A</sub> receptor agonist, serotonergic psychedelic, and anti-inflammatory drug of the phenethylamine, amphetamine, and DOx families.
DOIB is active at doses of 10 to 15mg orally, and hence is about one-third as potent as DOM.
DOIB is a full agonist of the serotonin 5-HT<sub>2A</sub> receptor, with an of 12.6nM and an of 98.8%, both for calcium mobilization. It is about one-third as potent as DOM in rodent drug discrimination tests and also substitutes for LSD in these tests. In addition to its psychedelic effects, DOIB has highly potent anti-inflammatory effects in preclinical research. It was more potent than almost any other tested psychedelic. The drug was notably more potent than (R)-DOI, but was less potent than 2C-I (the most potent assessed compound).
The chemical synthesis of DOIB has been described.
DOIB is part of the series of straight-chain and branched-chain 4-alkylated DOx drugs that also includes DOM, DOET, DOPR, DOBU, DOAM, and DOHx, among others.
Some other notable analogues of DOIB include DOBU (n-butyl), DOSB (sec-butyl), and DOTB (tert-butyl).
DOIB is a controlled substance in Canada under phenethylamine blanket-ban language.