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    2C-I molecular structure

    2C-I Stats & Data

    2ci
    PubChem
    MW307.13
    FormulaC10H14INO2
    LogP1.8
    IUPAC2-(4-iodo-2,5-dimethoxyphenyl)ethanamine
    SMILESCOC1=CC(=C(C=C1CCN)OC)I
    InChIKeyPQHQBRJAAZQXHL-UHFFFAOYSA-N
    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 Effects

    Physical
    • Spontaneous tactile sensations: The body high of 2C-I is manifested as one of the most proportionally intense in comparison to almost all of the classical psychedelics. The sensation itself can be described as an intense and slightly uncomfortable energetic pins and needles sensation that constantly encompasses a person's entire body. It is usually felt over every square inch of the skin but occasionally manifests itself in the form of a continuously shifting tingling sensation that travels up and down the body in spontaneous waves. Alongside of this, many users commonly report that the body high can be particularly uncomfortable and sometimes accompanied by dysphoric aches and urges to shift the position of one's body and prolonged tensing of unusual combinations of muscle groups.
    • Physical euphoria: Feelings of frequent but unpredictable rushes of warm physical euphoria are extremely common and very pleasurable. These move from the top of the head downwards before enveloping one's whole body.
    • Stimulation: In terms of its effects on the physical energy levels of the tripper, 2C-I is usually considered to be very energetic and stimulating in a fashion that is quite comparable to that of MDMA although encouraged instead of forced.
    • Increased bodily control
    • Tactile enhancement
    • Nausea: Mild to extreme nausea is consistently reported when consumed in moderate to high dosages and either passes once the tripper has vomited or gradually fades by itself as the peak sets in.
    • Temperature regulation loss
    • Headaches: Some users report mild but uncomfortable head pressures which can occasionally intensify during the offset of the experience.
    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.

    • Empathy, love and sociability enhancement: This component is consistently manifested only in the context of social settings in which one is within the company of others. These feelings of sociability, love and empathy are a little weaker and less sharp than those found on substances such as MDMA and 2C-B but still prove strong enough to provide long lasting therapeutic effects.
    • Time distortion
    • Feelings of fascination, importance and awe
    • Sexual arousal
    • Current mind state enhancement
    • Ego suppression, loss and death
    • Unity and interconnectedness
    Sensory
    Auditory
    • Enhancements
    • Distortions
    • Hallucinations
    Visual · Distortions
    • Visual drifting: (Melting, Flowing, Breathing and Morphing) - In comparison to other psychedelics, this effect can be described as simplistic and bland in detail, slow and smooth but sometimes jittery in motion, static in appearance and unrealistic/cartoon-like in style.
    • Tracers
    • Symmetrical texture repetition: In comparison to other psychedelics such as LSD and 2C-E this particular effect is bland and simplistic.
    • Colour shifting
    • Scenery slicing
    Visual · Enhancements
    • Increased visual acuity
    • Enhancement of colour
    • Enhanced pattern recognition
    Visual · Hallucinatory States

    Like LSD, while 2C-I is capable of producing a full range of low and high level hallucinatory states, this is extremely rare and inconsistent at higher levels but common at lower levels.

    • External hallucinations: The experience of effects such as open eye transformations are common within 2C-I but not consistent.
    • Internal hallucinations: Although 2C-I is technically capable of producing hallucinatory states in a fashion that is on par with psilocin or DMT in its vividness and intensity, in comparison, these effects are extremely rare and inconsistent. Whilst traditional psychedelics such as LSA, ayahuasca and mescaline will induce internal hallucinations near consistently at level 5 geometry and above, 2C-I hallucinations will not extend beyond imagery and higher dosages will for most simply go straight into Level 7A visual geometry. This lack of consistently induced hallucinatory breakthroughs means that for most, 2C-I is simply not as deep of an experience as certain other psychedelics.

    Forked from Subjective Effect Documentation by Josie Kins, March 2014. Via dose.wiki (CC0).

    Toxicity

    PsychonautWiki

    The toxicity and long-term health effects of recreational 2C-I use do not seem to have been studied in any scientific context and the exact toxic dose is unknown. This is because 2C-I is a research chemical with very little history of human usage. Anecdotal reports from those who have tried 2C-I suggests that there are no negative health effects attributed to simply trying the substance by itself at low to moderate doses and using it very sparingly (but nothing can be completely guaranteed). Independent research should always be done to ensure that a combination of two or more substances is safe before consumption. It is strongly recommended that one use harm reduction practices, such as volumetric dosing, when using this substance so as to ensure the accurate administration of the intended dose.

    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

    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.

    Tolerance Decay

    Half tolerance 5d Baseline ~10d

    Subjective tolerance to classical psychedelics rises acutely and tends to decrease substantially over 3–7 days and return near baseline by 1–2 weeks; cross‑tolerance across serotonergic psychedelics is common, though exact ratios are not quantified.

    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

    View data table
    Effect Light (n=21) Common (n=120) Strong (n=136) Heavy (n=39)
    Visual Distortions 81.0% 90.0% 85.3% 97.4%
    Anxiety 66.7% 43.3% 42.6% 41.0%
    Stimulation 61.9% 63.3% 46.3% 41.0%
    Color Enhancement 38.1% 60.0% 61.8% 43.6%
    Euphoria 28.6% 55.0% 41.2% 35.9%
    Music Enhancement 52.4% 52.5% 50.0% 46.2%
    Empathy 47.6% 41.7% 40.4% 38.5%
    Nausea 47.6% 35.0% 27.9% 35.9%
    Tactile Enhancement 42.9% 35.8% 35.3% 35.9%
    Confusion 28.6% 34.2% 38.2% 35.9%
    Sedation 28.6% 37.5% 36.8% 17.9%
    Closed-Eye Visuals 33.3% 30.8% 22.8% 20.5%
    Auditory Effects 33.3% 25.0% 27.2% 23.1%
    Introspection 9.5% 33.3% 25.0% 25.6%
    Focus Enhancement 19.0% 30.0% 30.9% 25.6%

    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.

    Oral dose range: 15.0–21.0 mg (median 20.0 mg)
    Effect Light (n=21) Common (n=120) Strong (n=136) Heavy (n=39)
    visual distortions
    81%
    90%
    85%
    97%
    anxiety
    67%
    43%
    43%
    41%
    stimulation
    62%
    63%
    46%
    41%
    color enhancement
    38%
    60%
    62%
    44%
    euphoria
    29%
    55%
    41%
    36%
    music enhancement
    52%
    52%
    50%
    46%
    empathy
    48%
    42%
    40%
    38%
    nausea
    48%
    35%
    28%
    36%
    tactile enhancement
    43%
    36%
    35%
    36%
    confusion
    29%
    34%
    38%
    36%
    sedation
    29%
    38%
    37%
    18%
    closed-eye visuals
    33%
    31%
    23%
    20%
    auditory effects
    33%
    25%
    27%
    23%
    introspection
    10%
    33%
    25%
    26%
    focus enhancement
    19%
    30%
    31%
    26%
    ego dissolution
    29%
    14%
    12%
    10%
    body high
    14%
    25%
    26%
    26%
    jaw clenching
    24%
    14%
    8%
    5%
    open-eye visuals
    14%
    16%
    23%
    15%
    muscle tension
    14%
    22%
    15%
    5%

    Showing top 20 of 34 effects

    Risk Escalation

    Sentiment Analysis

    Average frequency of positive vs adverse effects across dose tiers

    Light n=21
    9 positive 34.9% 10 adverse 24.8%
    Common n=120
    11 positive 37.0% 14 adverse 15.1%
    Strong n=136
    10 positive 36.2% 14 adverse 14.0%
    Heavy n=39
    10 positive 32.3% 11 adverse 16.6%
    View effect breakdown

    Adverse Effects

    Effect Light (n=21) Common (n=120) Strong (n=136) Heavy (n=39) Change
    Anxiety
    67%
    43%
    43%
    41%
    -38%
    Nausea
    48%
    35%
    28%
    36%
    -24%
    Confusion
    29%
    34%
    38%
    36%
    +25%
    Jaw Clenching
    24%
    14%
    8%
    5%
    -78%
    Muscle Tension
    14%
    22%
    15%
    5%
    -64%
    Pupil Dilation
    19%
    17%
    15%
    8%
    -59%
    Motor Impairment
    9%
    7%
    15%
    +67%
    Headache
    10%
    14%
    15%
    8%
    -18%
    Increased Heart Rate
    14%
    6%
    4%
    -69%
    Psychosis
    14%
    2%
    4%
    8%
    -46%
    Memory Suppression
    5%
    8%
    10%
    +106%
    Thought Loops
    3%
    5%
    10%
    +212%
    Appetite Suppression
    10%
    2%
    2%
    -76%
    Sweating
    4%
    4%
    -11%

    Positive Effects

    Effect Light (n=21) Common (n=120) Strong (n=136) Heavy (n=39) Change
    Stimulation
    62%
    63%
    46%
    41%
    -33%
    Color Enhancement
    38%
    60%
    62%
    44%
    +14%
    Euphoria
    29%
    55%
    41%
    36%
    +25%
    Music Enhancement
    52%
    52%
    50%
    46%
    -11%
    Empathy
    48%
    42%
    40%
    38%
    -19%
    Tactile Enhancement
    43%
    36%
    35%
    36%
    -16%
    Introspection
    10%
    33%
    25%
    26%
    +169%
    Focus Enhancement
    19%
    30%
    31%
    26%
    +34%
    Body High
    14%
    25%
    26%
    26%
    +79%
    Creativity Enhancement
    8%
    6%
    5%
    -38%
    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

    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.

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