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    2C-I molecular structure

    2C-I Stats & Data

    Psychedelic Research-chemical
    2ci
    NPS DataHub
    MW343.59
    FormulaC10H15ClINO2
    CAS64584-32-3
    IUPAC4-Iodo-2,5-dimethoxyphenethylamine hydrochloride
    SMILES[Cl-].NCCc1cc(OC)c(I)cc1OC.[H+]
    InChIKeyOTUXWIRPEPMONF-UHFFFAOYSA-N
    Phenethylamines; 2020/1. Von 2-Phenethylamin abgeleitete Verbindungen; 2021/1. Von 2-Phenethylamin abgeleitete Verbindungen; 2022/1. Von 2-Phenethylamin abgeleitete Verbindungen
    Chemical Class Phenethylamine
    Psychoactive Class Psychedelic
    Half-Life Unknown in humans; subjective effect window consistent with several hours of action (often cited ~4–6 h), but no formal human PK published.

    Pharmacology

    DrugBank

    Description

    2C-I is a lesser known psychedelic of the substituted phenethylamine class. In the early 2000s, 2C-I was sold in Dutch smart shops after the drug 2C-B was banned.

    Receptor Profile

    Receptor Actions

    Agonists
    5-HT2A receptor agonist (partial)
    5-HT2B receptor agonist
    5-HT2C receptor agonist

    History & Culture

    1976–1991

    2C-I was first synthesized and investigated for human activity by Alexander Shulgin in the mid-to-late 1970s. The compound was initially described in scientific literature in 1977, with its properties and effects in humans documented the following year. Shulgin later provided a more comprehensive account of his research with 2C-I in his 1991 book PiHKAL (Phenethylamines I Have Known and Loved), which brought the substance to wider public awareness within psychedelic research communities. The presence of a heavy iodine atom in the molecule made 2C-I particularly suitable for radio-labeling experiments. The compound has been synthesized with radioactive iodine for research purposes, though more extensive radiological findings have emerged from studies using its three-carbon amphetamine analog, DOI.

    1995–2004

    2C-I began to emerge as a recreational substance in the late 1990s, initially gaining popularity in Dutch smart shops where it was sold as a legal alternative to 2C-B following that compound's scheduling in 1995. The substance became more widely available through grey market online vendors around 2002, marketed as a "research chemical" alongside other novel psychoactive substances. Distribution significantly declined after a series of DEA enforcement actions in 2004 that targeted vendors selling research chemicals intended for human consumption. Throughout its period of availability, 2C-I was sometimes confused with the structurally related but considerably more potent compound 25I-NBOMe, which media outlets subsequently nicknamed "Smiles." This confusion has contributed to ongoing concerns about accurate identification and appropriate harm reduction information for users.

    Subjective Effect Notes

    cognitive: The head space of 2C-I is described by many as one which is relatively normal in its thought processes even at moderate to high dosages. It is often said to lack insight when compared to that of 2C-E, 2C-B and LSD.

    Effect Profile

    Curated + 650 Reports
    Psychedelic 8.8

    Strong visuals, headspace, auditory effects, and body load

    Visual Intensity×3
    10103.8
    Headspace Depth×3
    109.52.4
    Auditory Effects×1
    10101.0
    Body Load / Somatic Effects×1
    10102.8
    Catalog Erowid BlueLight
    Based on reports from:
    Effect Index Agile and Competent — nervewing Effect Index Manic Cleaning Frenzy — nervewing PiHKAL PiHKAL #33: 2C-I Bluelight Big & Dandy Thread Erowid Experience Reports PsychonautWiki 2C-I The Drug Users Bible 2C-I

    Duration Timeline

    Bluelight
    Onset Comeup Peak Offset After Effects
    Insufflated
    45 minutes - 2.0 hours
    4.0-8.0 hours
    4.0-12.0 hours
    Oral
    12-48 minutes
    48 minutes - 1.5 hours
    3-5 hours
    2-3 hours
    6-24 hours
    Total: 5-10 hours

    Empirical Duration

    Erowid Reports
    Onset Come Up Peak Offset
    Oral (82 reports)

    Community Effects

    TripSit
    Positive
    visual enhancement euphoria stimulation color enhancement
    Negative
    nausea body load vasoconstriction

    Tolerance & Pharmacokinetics

    drugs.wiki
    Half-Life
    Unknown in humans; subjective effect window consistent with several hours of action (often cited ~4–6 h), but no formal human PK published.
    Addiction Potential
    Low; 2C-I is not considered physically addictive, though psychological habituation is possible with frequent use.

    Experience Report Analysis

    Erowid BlueLight
    508 Reports
    2000–2025 Date Range
    124 With Age Data
    32 Effects Detected

    Demographics

    Gender Distribution

    Age Distribution

    Reports Over Time

    Effect Analysis

    Erowid + Bluelight

    Effects aggregated from 558 experience reports (508 Erowid + 142 Bluelight)

    558 Reports
    157 Effects Detected
    73 Positive
    45 Adverse
    39 Neutral

    Effect Sentiment Distribution

    Confidence Distribution

    Positive Effects 73

    Color Enhancement 53.7% 87%
    Stimulation 50.7% 86%
    Surface Breathing 48.0% 86%
    Music Enhancement 45.5% 90%
    Euphoria 42.1% 88%
    Awe 38.0% 84%
    Empathy 36.9% 82%
    Visual Trails 36.0% 87%
    Tactile Enhancement 30.5% 85%
    Introspection 28.0% 85%
    Joy 28.0% 88%
    Focus Enhancement 25.8% 82%
    Body High 24.4% 85%
    Insight 24.0% 84%
    Patterning 22.0% 86%
    Morphing 22.0% 87%
    Melting/flowing 22.0% 87%
    Geometric Imagery 20.0% 86%
    Warping 18.0% 86%
    Sociability Enhancement 18.0% 84%

    Adverse Effects 45

    Anxiety 43.8% 86%
    Confusion 30.3% 85%
    Nausea 29.7% 85%
    Body Load 22.0% 84%
    Tremor 16.0% 83%
    Muscle Tension 15.2% 81%
    Pupil Dilation 14.4% 84%
    Jaw Clenching 12.0% 85%
    Restlessness 12.0% 83%
    Paranoia 12.0% 75%
    Headache 11.6% 68%
    Fear 8.0% 89%
    Depersonalization 8.0% 81%
    Motor Impairment 6.6% 75%
    Stomach Cramps 6.0% 80%
    Panic 6.0% 84%
    Increased Heart Rate 5.9% 70%
    Memory Suppression 5.5% 77%
    Thought Loops 5.2% 80%
    Sweating 5.2% 84%

    Dose-Response Correlation

    How effect frequency changes across dose levels

    Oral

    View data table
    Effect Light (n=14) Common (n=109) Strong (n=124) Heavy (n=33)
    Visual Distortions 78.6% 90.8% 84.7% 100.0%
    Anxiety 78.6% 44.0% 42.7% 45.5%
    Stimulation 71.4% 66.1% 46.0% 45.5%
    Empathy 64.3% 40.4% 41.9% 33.3%
    Color Enhancement 35.7% 62.4% 62.1% 45.5%
    Music Enhancement 57.1% 54.1% 49.2% 42.4%
    Euphoria 28.6% 56.0% 41.9% 30.3%
    Nausea 42.9% 36.7% 26.6% 33.3%
    Sedation 35.7% 39.4% 39.5% 18.2%
    Tactile Enhancement 35.7% 36.7% 36.3% 39.4%
    Confusion 28.6% 32.1% 37.9% 33.3%
    Auditory Effects 35.7% 26.6% 27.4% 24.2%
    Ego Dissolution 35.7% 15.6% 12.9% 12.1%
    Introspection 0% 33.9% 24.2% 24.2%
    Focus Enhancement 14.3% 32.1% 30.6% 30.3%

    Insufflated

    View data table
    Effect Heavy (n=29)
    Visual Distortions 86.2%
    Music Enhancement 51.7%
    Confusion 48.3%
    Color Enhancement 44.8%
    Euphoria 44.8%
    Empathy 44.8%
    Stimulation 37.9%
    Nausea 34.5%
    Anxiety 34.5%
    Introspection 31.0%
    Tactile Enhancement 24.1%
    Body High 20.7%
    Focus Enhancement 17.2%
    Auditory Effects 17.2%
    Open-Eye Visuals 17.2%

    Subjective Effect Ontology

    Experience Reports

    Structured effect tags extracted from 650 Erowid & Bluelight experience reports using a controlled vocabulary of 220+ canonical effects across 15 domains.

    Auditory

    music enhancement 254 43.3%

    Cognitive

    confusion 169 26.3% introspection 156 28.6% focus enhancement 144 23.0%

    Emotional

    anxiety 244 40.1% euphoria 235 40.7% empathy 206 34.5%

    Gastrointestinal

    nausea 166 29.2%

    Motor

    stimulation 283 51.2% sedation 149 29.3%

    Somatic

    body high 136 25.2%

    Tactile

    tactile enhancement 170 27.9%

    Visual

    visual distortions 432 67.6% color enhancement 300 52.1% closed eye visuals 138 25.2% open eye visuals 103 18.7%

    16 unique effects extracted · Derived from Erowid & Bluelight reports

    Dose–Effect Mapping

    Experience Reports

    How reported effects shift across dose tiers, based on 508 experience reports.

    Insufflated dose range: 10.0–25.0 mg (median 20.0 mg)
    Effect Heavy (n=29)
    visual distortions
    86%
    music enhancement
    52%
    confusion
    48%
    color enhancement
    45%
    euphoria
    45%
    empathy
    45%
    stimulation
    38%
    nausea
    34%
    anxiety
    34%
    introspection
    31%
    tactile enhancement
    24%
    body high
    21%
    focus enhancement
    17%
    auditory effects
    17%
    open-eye visuals
    17%
    dissociation
    14%
    hospital
    14%
    sedation
    14%
    headache
    14%
    closed-eye visuals
    10%

    Showing top 20 of 22 effects

    Oral dose range: 15.0–21.0 mg (median 20.0 mg)
    Effect Light (n=14) Common (n=109) Strong (n=124) Heavy (n=33)
    visual distortions
    79%
    91%
    85%
    100%
    		↑
    anxiety
    79%
    44%
    43%
    46%
    		↓
    stimulation
    71%
    66%
    46%
    46%
    		↓
    empathy
    64%
    40%
    42%
    33%
    		↓
    color enhancement
    36%
    62%
    62%
    46%
    		↑
    music enhancement
    57%
    54%
    49%
    42%
    		↓
    euphoria
    29%
    56%
    42%
    30%
    		→
    nausea
    43%
    37%
    27%
    33%
    		↓
    sedation
    36%
    39%
    40%
    18%
    		↓
    tactile enhancement
    36%
    37%
    36%
    39%
    		→
    confusion
    29%
    32%
    38%
    33%
    		↑
    auditory effects
    36%
    27%
    27%
    24%
    		↓
    ego dissolution
    36%
    16%
    13%
    12%
    		↓
    introspection —
    34%
    24%
    24%
    		↓
    focus enhancement
    14%
    32%
    31%
    30%
    		↑
    closed-eye visuals
    29%
    31%
    25%
    24%
    		↓
    body high
    14%
    26%
    27%
    21%
    		↑
    open-eye visuals
    21%
    16%
    23%
    15%
    		↓
    muscle tension —
    23%
    15%
    6%
    		↓
    jaw clenching
    21%
    16%
    8%
    6%
    		↓

    Showing top 20 of 34 effects

    Risk Escalation

    Sentiment Analysis

    Average frequency of positive vs adverse effects across dose tiers (Oral)

    Light n=14
    8 positive 40.2% 6 adverse 33.4%
    Common n=109
    11 positive 38.0% 14 adverse 15.7%
    Strong n=124
    10 positive 36.6% 14 adverse 14.2%
    Heavy n=33
    10 positive 31.8% 11 adverse 17.4%
    View effect breakdown

    Adverse Effects

    Effect Light (n=14) Common (n=109) Strong (n=124) Heavy (n=33) Change
    Anxiety
    79%
    44%
    43%
    46%
    		-42%
    Nausea
    43%
    37%
    27%
    33%
    		-22%
    Confusion
    29%
    32%
    38%
    33%
    		+16%
    Muscle Tension —
    23%
    15%
    6%
    		-73%
    Jaw Clenching
    21%
    16%
    8%
    6%
    		-71%
    Pupil Dilation
    14%
    18%
    16%
    9%
    		-36%
    Motor Impairment —
    10%
    7%
    18%
    		+80%
    Headache —
    15%
    14%
    6%
    		-58%
    Psychosis
    14%
    3%
    5%
    9%
    		-36%
    Memory Suppression —
    6%
    8%
    12%
    		+120%
    Thought Loops —
    4%
    6%
    12%
    		+227%
    Increased Heart Rate —
    6%
    5%
    		— -25%
    Sweating —
    5%
    4%
    		— -13%
    Appetite Suppression —
    2%
    2%
    		— +33%

    Positive Effects

    Effect Light (n=14) Common (n=109) Strong (n=124) Heavy (n=33) Change
    Stimulation
    71%
    66%
    46%
    46%
    		-36%
    Empathy
    64%
    40%
    42%
    33%
    		-48%
    Color Enhancement
    36%
    62%
    62%
    46%
    		+27%
    Music Enhancement
    57%
    54%
    49%
    42%
    		-25%
    Euphoria
    29%
    56%
    42%
    30%
    		5%
    Tactile Enhancement
    36%
    37%
    36%
    39%
    		10%
    Introspection —
    34%
    24%
    24%
    		-28%
    Focus Enhancement
    14%
    32%
    31%
    30%
    		+111%
    Body High
    14%
    26%
    27%
    21%
    		+48%
    Creativity Enhancement —
    8%
    6%
    6%
    		-26%
    Pain Relief —
    2%
    		— — 0%

    Dosage Distribution

    Dose distribution from experience reports

    Oral

    Median: 20.0 mg IQR: 15.0–21.0 mg n=284

    Insufflated

    Median: 20.0 mg IQR: 10.0–25.0 mg n=20

    Real-World Dose Distribution

    62K Doses

    From 591 individual dose entries

    Oral (n=466)

    Median: 20.0mg 25th: 15.0mg 75th: 20.0mg 90th: 25.0mg
    mg/kg median: 0.252 mg/kg 75th: 0.315

    Insufflated (n=42)

    Median: 12.0mg 25th: 5.0mg 75th: 20.0mg 90th: 29.5mg
    mg/kg median: 0.173 mg/kg 75th: 0.248

    Smoked (n=9)

    Median: 6.0mg 25th: 4.0mg 75th: 10.0mg 90th: 21.0mg
    mg/kg median: 0.088 mg/kg 75th: 0.13

    Common Combinations

    Most co-occurring substances in experience reports

    Form / Preparation

    Most common forms and preparations reported

    Body-Weight Dosing

    Dose relative to body weight from reports with weight data

    Oral

    Median: 0.252 mg/kg IQR: 0.214–0.315 mg/kg n=277

    Insufflated

    Median: 0.238 mg/kg IQR: 0.115–0.353 mg/kg n=19

    Smoked

    Median: 0.088 mg/kg IQR: 0.053–0.13 mg/kg n=5

    Unknown

    Median: 0.255 mg/kg IQR: 0.228–0.261 mg/kg n=10

    Redose Patterns

    Redosing behavior across 377 reports

    13.8% Redosed
    1.2 Avg Doses
    60m Median Interval
    Read full reports on Erowid →

    Legal Status

    EU Council Decision 2003/847/JHA (December 2003) - Binding order compelling all member states to control 2C-I within three months
    Country Status Notes
    Australia Schedule 9 Prohibited substance under the Poisons Standard. The National Drugs and Poisons Schedule Committee formally added 2C-I to Schedule 9 (the most restrictive category) in 2005.
    Austria Illegal (SMG) Controlled under the Suchtmittelgesetz (Narcotics Act). Possession, production, and sale are prohibited.
    Belgium Illegal Added to the list of illegal psychotropic substances on November 8, 2004.
    Brazil Illegal Possession, production, and sale prohibited under Portaria SVS/MS nº 344. Controlled as of February 18, 2014.
    Canada Schedule III (CDSA) Controlled under the Controlled Drugs and Substances Act as of October 31, 2016.
    China Category I Psychotropic Substance Illegal to sell, buy, import, export, and manufacture as of September 2010.
    Czech Republic Controlled Added to controlled substance lists in early 2011 alongside BZP, synthetic cannabinoids, and various cathinone derivatives.
    Denmark Controlled Classified as a controlled substance since May 2002.
    Estonia Schedule I Added to Schedule I in February 2011 alongside various synthetic cathinones and cannabinoids.
    Finland Illegal Scheduled under the government decree on substances, preparations, and plants considered to be narcotic drugs.
    France Controlled Added to the list of controlled substances in August 2004 as a synthetic analogue of mescaline.
    Germany Anlage I BtMG Controlled under Anlage I of the Betäubungsmittelgesetz (Narcotics Act) as of October 10, 1999. Manufacturing, possession, import, export, purchase, sale, procurement, and dispensing without license are prohibited.
    Greece Controlled Illegal to possess under Table A of Law 1729/87.
    Ireland Schedule 1 Controlled as a Schedule 1 substance, prohibiting possession and distribution.
    Israel Controlled Added to the list of controlled substances in December 2007, making purchase, sale, and possession illegal.
    Italy Tabella I Added to Tabella 1 (list of prohibited plants and substances) by Ministry of Health statement on January 11, 2005.
    Japan Designated Substance (Shitei-Yakubutsu) Controlled under the Pharmaceutical Affairs Law, making possession and sale illegal.
    Latvia Schedule I Classified as a Schedule I controlled substance.
    Netherlands Controlled Classified as a controlled substance under national drug legislation.
    New Zealand Schedule 3 / Class C Controlled under the catch-all analogues provision in Schedule 3 / Class C of national drug laws.
    Poland Controlled Classified as a controlled substance under national drug legislation.
    Portugal Controlled Legislation enacted in January 2005 to control 2C-I alongside 2C-T-2, 2C-T-7, and TMA-2.
    Sweden Schedule I (Narcotic) Added to Schedule I by Sveriges riksdag on March 16, 2004, published in Medical Products Agency regulation LVFS 2004:3. Classified as a substance normally without medical use.
    Switzerland Controlled (Verzeichnis D) Listed in Anhang D of the Betäubungsmittelverzeichnisverordnung (DetMV) since December 12, 1996. Possession is illegal.
    Turkey Illegal Classified as a drug. Possession, production, supply, and import are prohibited.
    United Kingdom Class A Controlled under the Misuse of Drugs Act 1971 via the phenethylamine catch-all clause. Class A carries the most severe penalties for possession and supply.
    United States Schedule I Controlled under the Synthetic Drug Abuse Prevention Act of 2012, effective July 9, 2012. Possession, distribution, and manufacture are federal offenses. Several states including Minnesota, Oklahoma, and Wisconsin had scheduled the substance prior to federal action.

    Harm Reduction

    drugs.wiki

    Identity and misrepresentation: 2C‑I has often been confused with or sold as 25I‑NBOMe/NBOH; NBOMe compounds are active at microgram doses, can cause local oral numbness and intense bitterness, are not reliably active when simply swallowed, and have been linked to hospitalizations and deaths—test samples and avoid blotters claimed to be “2C‑I.” Use multiple reagents and, ideally, lab testing (FTIR/GC‑MS) when possible. Redosing: EMCDDA notes 2C‑I can have a slower onset than expected, which has led some users to prematurely redose or add other drugs; wait at least 2 hours after an oral dose before considering any change. Intranasal risks: snorting 2C‑x (including 2C‑I) is frequently reported as extremely painful and more likely to cause nausea, vomiting, and a harsh stimulant edge; many experienced users avoid the route—if used, reduce dose markedly and expect severe nasal irritation. Cardiovascular strain: phenomenology and receptor data (5‑HT2A/2C and potential alpha‑1 adrenergic action) imply vasoconstriction, mild tachycardia and blood‑pressure elevation; those with cardiovascular disease, hypertension, or migraine susceptibility should avoid use and all users should minimize exertion/overheating. Serotonergic/seizure‑threshold cautions: avoid combinations with MAOIs entirely and with tramadol due to seizure and serotonin‑toxicity risks; SSRIs/SNRIs may blunt effects and complicate response. Lithium is specifically flagged as dangerous with classical serotonergic psychedelics due to seizure risk; do not combine. Set and setting: stimulation can amplify anxiety—use with a trusted sober sitter in a calm environment; avoid crowded, hot venues on first trials. Hydration and temperature: sip water periodically (not excessively) and take cool breaks if active; overheating increases risk with stimulating psychedelics. Dosing discipline: always allergy test with a very small amount (e.g., 1–3 mg oral), then titrate across separate sessions using a 0.001 g scale; never eyeball. Sleep and after‑effects: residual stimulation can impair sleep into the next day; plan recovery time and do not drive or operate machinery for at least 12–24 hours after significant effects resolve. Legal and substitution risk: 2C‑I is Schedule I in the U.S. and controlled in many countries; the market has historically included mislabeling (including NBOMe and DOx) so reagent test each sample.

    References

    Data Sources

    Cited References

    Drugs.wiki References

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