Research chemicalResearch chemicalPhenethylaminePsychedelic

DOI

Also known as 4-iodo-2,5-dimethoxyamphetamine

Written by enwyReviewed 4 Aug 20262 sources0 comments

DOI (4-iodo-2,5-dimethoxyamphetamine) is a potent, long-lasting psychedelic amphetamine of the DOx family. It is widely used as a 5-HT2A agonist in laboratory pharmacology, but human recreational data are limited to anecdote. Active doses are small, onset is slow, effects last 12-24 hours, and vasoconstriction is a recognised risk.

01 Overview

DOI is best known scientifically as a radioligand and pharmacological tool for studying serotonin 5-HT2A receptors, where it is a potent agonist. In humans it behaves as a long-acting psychedelic amphetamine similar in profile to DOB, with slow onset and a duration measured in many hours.

As with other DOx compounds, the low active dose and slow onset make dosing error and premature redosing common problems, and vasoconstriction is reported. Despite its extensive use in preclinical neuroscience, controlled human studies of its subjective effects and toxicology do not exist.

02 Mechanism

Potent, long-acting agonist at serotonin 5-HT2A receptors; widely used as a 5-HT2A agonist reference compound in preclinical research.

03 Dosing

Tier	Dose	Route	Notes
Threshold	0.5–1 mg	Oral	Slow onset; do not redose early.
Common	1.5–3 mg	Oral	Range from anecdote; narrow margin.
Strong	3–5 mg	Oral	Long duration and increased vasoconstriction risk.

04 Effects

Effect	Magnitude	Evidence
Long-lasting visual psychedeliaExtended visual and perceptual effects with mild stimulation.	strong	Anecdotal
Very long durationEffects persist for most of a day.	12-24 h	Anecdotal
Cognitive and emotional alterationIntrospective, thought-altering states.		Anecdotal

05 Side effects

Effect	Severity	Frequency	Evidence
InsomniaDifficulty sleeping due to the long, stimulating tail.	Mild	Common	Anecdotal
VasoconstrictionCold extremities and reduced peripheral circulation reported, as with other DOx compounds.	Moderate	Common, dose-dependent	Anecdotal
Premature redosing / overwhelming experienceSlow onset leads to redosing before the first dose peaks.	Severe	Common	Anecdotal

06 Legal status

Germany

BtMG / NpSG

Controlled. · as of Jan 2026

United States

Schedule I

May be prosecuted under analogue provisions; treated as controlled. · as of Jan 2026

07 References

Nichols DE. Hallucinogens (pharmacology review including DOI as 5-HT2A agonist)Pharmacology & Therapeutics, 2004

DOI entryPsychonautWiki

08 Discussion0 comments

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This page is reference information, not medical advice. Doses and protocols are documented as they appear in the clinical literature and in practice — describing them is not a recommendation to use them. Countermeasures listed here are not a substitute for a physician. Legal status varies by jurisdiction and changes.