DOI
1-(4-iodo-2,5-dimethoxyphenyl)propan-2-amine
Overview
DOI belongs to Psychedelics / Phenethylamines.
Key safety note: DOI is very potent (active at roughly 1.5–3 mg) and exceptionally long-acting, with an unpredictable duration (about 16–30 hours) and long-lasting residual stimulation and insomnia that can persist for days, so precise low dosing (ideally volumetric) is essential and redosing is hazardous.[4][3]
Effects
Subjective effects vary. What a substance feels like depends on dose, individual physiology,
mindset, and setting. The points below describe commonly reported effects, not guaranteed, uniform, or
desirable outcomes.
- Intensely and long-lastingly stimulating, described as more stimulating than LSD, with a powerful amplification of the user's current mindset
- A pronounced body load (pins-and-needles, tactile enhancement) alongside strong internal and external visual hallucinations
- A comparatively less complex, more 'amphetamine-like' headspace, with wakefulness and difficulty sleeping that can outlast the main effects by days
Dosing & duration
Harm-reduction note: These are commonly cited reference ranges, not a recommendation or a
“safe” dose. Potency, purity, body chemistry, tolerance, and drug combinations vary widely. Start
low, go slow, wait for full effects before redosing, and never assume an unknown product matches these
figures. Missing data is not evidence of safety.
Oral. DOI is very potent and exceptionally long-acting, so precise low dosing (ideally volumetric from a solution) is essential. Common oral doses are only ~1.5–3 mg (about 1–2 mg for the more active (R)-DOI). Effects come up slowly (often 1–3 hours), which can tempt redosing: do not redose. Expect a very long experience with residual stimulation for hours to days.
Dose ranges
Threshold
~0.5 mg
Light
0.5–1 mg
Common
1–2 mg
Strong
2–3 mg
Duration
onset
1–2 h
peak
several hours
total
16–24 h (can extend to ~30 h)
Chemical & Physical Properties
| Formula | C11H16INO2 |
| Molar mass | 321.15 g/mol |
| State | Solid (usually the hydrochloride salt) |
| Melting point | 201.5 °C (hydrochloride salt) |
| Boiling point | unavailable: true. reason: a crystalline solid that decomposes on strong heating rather than boiling. No reliable experimental boiling point is reported |
| Density | unavailable: true. reason: no reliable experimental value is reported for the solid |
| Vapor pressure | Not reported |
| pKa | Not reported |
| LogP | 2.5 (predicted, XLogP3) |
| Solubility | Water: 10 mg/mL (hydrochloride salt) |
| Refractive index | Not reported |
Identifiers & Synonyms
| CAS | 64584-34-5 |
| CAS (enantiomer) | |
| PubChem CID | 1229 |
| InChIKey | BGMZUEKZENQUJY-UHFFFAOYSA-N |
| InChI | InChI=1S/C11H16INO2/c1-7(13)4-8-5-11(15-3)9(12)6-10(8)14-2/h5-7H,4,13H2,1-3H3 |
| SMILES | CC(CC1=CC(=C(C=C1OC)I)OC)N |
Synonyms
- 4-Iodo-2,5-dimethoxyamphetamine
- [125I]DOI (radioligand form)
- DOI
Pharmacodynamics & Biochemistry
A potent, very long-acting psychedelic phenethylamine: the 4-iodo member of the DOx (amphetamine) series and a close analogue of DOB. It is a potent serotonin 5-HT2 receptor agonist, selective for 5-HT2A over 5-HT2C (roughly 5–12-fold), and shows biased agonism at 5-HT2C. Unlike the classic amphetamines it is not a monoamine-releasing agent. (R)-(−)-DOI is the more active enantiomer (eutomer). The radioiodinated form, [125I]DOI, is one of the most widely used radioligands for labelling and studying 5-HT2A receptors in research. At sub-behavioural doses (R)-DOI has attracted research interest for potent anti-inflammatory effects (picomolar inhibition of TNF-α signalling) and for inducing 5-HT2A-mediated dendritic-spine remodelling (neuroplasticity).
Biological targets
- 5-HT2A
- 5-HT2C
- 5-HT2B
Binding & functional measurements
| Target | Measurement | Species |
|---|---|---|
| 5-HT2A receptor | Ki 0.70 ± 0.06 nM | Human |
| 5-HT2B receptor | Ki 20 ± 3.6 nM | Human |
| 5-HT2C receptor | Ki 2.4 ± 0.30 nM | Human |
| α2A-adrenoceptor | Ki 74 nM | Human |
| β2-adrenoceptor | Ki 139 nM | Human |
| α2B-adrenoceptor | Ki 340 nM | Human |
| 5-HT1D receptor | Ki 458 nM | Human |
| M4 receptor | Ki 578 nM | Human |
| β1-adrenoceptor | Ki 591 nM | Human |
| α2C-adrenoceptor | Ki 601 nM | Human |
| Serotonin transporter | Ki 685 nM | Human |
| 5-HT5B receptor | Ki 1,000 nM | Rat |
| 5-HT1E receptor | Ki 1,013 nM | Human |
| M3 muscarinic receptor | Ki 1,428 nM | Human |
| 5-HT1F receptor | Ki 1,739 nM | Human |
| H1 receptor | Ki 1,757 nM | Human |
| M2 receptor | Ki 1,989 nM | Human |
| 5-HT6 receptor | Ki 2,113 nM | Human |
| M5 receptor | Ki 2,208 nM | Human |
| 5-HT1A receptor | Ki 2,219 nM | Human |
| M1 receptor | Ki 2,720 nM | Human |
| 5-HT7 receptor | Ki 5,769 nM | Human |
| σ1 receptor | Ki 8,565 nM | Human |
| σ2 receptor | Ki 9,172 nM | Human |
| D1 receptor | Ki 9,688 nM | Human |
| 5-HT2A receptor | EC50 0.90 nM Emax 61% | Human |
| 5-HT2B receptor | EC50 1.4 nM Emax 65% | Human |
| 5-HT2C receptor | EC50 7.9 nM Emax 57% | Human |
Pharmacokinetics
| Bioavailability | Not reported |
| Tmax | Not reported |
| Half-life | Not established in humans, but effects are very long (≈16–30 h) |
| Vd | Not reported |
| Protein binding | Not reported |
| Metabolism | Hepatic. The α-methyl (amphetamine) group resists monoamine oxidase (MAO-A IC₅₀ ~37 µM), contributing to a very long duration of action. Detailed human metabolic pathways are not well characterised |
| Excretion | Not reported |
Toxicology & Safety
Harm-reduction note: Toxicity and risk depend on dose, route, purity, combinations, setting, and individual
health factors. Missing harms should never be interpreted as evidence of safety.
Not reported
DOI is very potent (active at roughly 1.5–3 mg) and exceptionally long-acting, with an unpredictable duration (about 16–30 hours) and long-lasting residual stimulation and insomnia that can persist for days, so precise low dosing (ideally volumetric) is essential and redosing is hazardous. As a DOx it causes vasoconstriction, usually at higher doses, which can be uncomfortable and persistent. In animals, high repeated doses of DOI produced serotonergic neurotoxicity that was partly blocked by 5-HT2A antagonists. It also strongly amplifies the user's current mental state, which can intensify anxiety. Limited human data must never be read as evidence of safety.[4][3]
Legal Status
Legal note: Legal status can change over time and may vary by country, region, formulation, analogue status,
prescription context, and enforcement practice. Always confirm with current official sources before relying on this section.
US: Not federally scheduled. UK: Class A. DE: BtMG Anlage I
Interactions & Contraindications
Drug interactions
Stimulants (amphetamines, cocaine), Vasoconstrictors Compound DOI's cardiovascular strain and vasoconstriction, a particular risk given its long duration.
Lithium, Tramadol Raise the risk of seizures and psychosis with psychedelics.
SSRIs, SNRIs, MAOIs Add to serotonergic load. MAOIs may unpredictably intensify and prolong effects.
Cannabis Can intensify effects and increase anxiety or panic.
Contraindications
Cardiovascular disease, hypertension or arrhythmia Raynaud's or other vascular conditions (DOx vasoconstriction).
Personal or family history of psychosis, schizophrenia or bipolar disorder
Concurrent MAOI, SSRI/SNRI or other serotonergic medication includes MAO inhibitors, and avoid concurrent vasoconstrictors or stimulants.
Settings where impairment or dissociation risks injury (driving, water, heights) extreme potency and 16-30 h duration.
No interactions or contraindications listed.
Usage & Context
- Research.
- Recreational.
Sources & Evidence
- Shulgin A, Shulgin A (1991). PiHKAL: A Chemical Love Story — entry #67 (DOI)
- Nichols DE (2016). Psychedelics. Pharmacol Rev 68:264-355.
PMID 26841800 · doi:10.1124/pr.115.011478
- PsychonautWiki: DOI (dosage, duration & effects) CC BY-SA 4.0
- Wikipedia: DOI (psychedelic) CC BY-SA 4.0
- Wikipedia chembox (melting point, solubility). PubChem CID 1229 (computed LogP) CC BY-SA 4.0