Skip to main content

25I-NBOMe

4-iodo-2,5-dimethoxy-N-(2-methoxybenzyl)phenethylamine

Viewing r1 — Apr 25, 2026 — CURRENT

Back to History

Interactions, related substances, and reports reflect the current entry and are not shown for historical revisions.

25I-NBOMe — N-Bomb, Smiles — is a synthetic psychedelic of the phenethylamine class. It is derived from 2C-I by a structural modification that increases potency by more than tenfold. It activates serotonin receptors in the brain, disrupting normal sensory filtering and producing the visual and cognitive shifts characteristic of psychedelics.[1]

Open Beta

Psychedex is in open beta. We are still fine-tuning the generation and review process. Please double-check sources.

Threshold
< 50 µg
Light
200 – 500 µg
Common
500 – 700 µg
Strong
700 – 1000 µg
Heavy
1000+ µg
123450 h2 h4 h6 h8 h9 h
1Onset
15m–2h2Come-up
30m–2h3Peak
2h–4h4Plateau
1h–2h5Resolution
1h–4hAftereffects24h–72h
Total6h–10h
Builduprapid
Full reset14 days
Cross-tol.
LSD, psilocybin, psilocin +6 more
Absolute6 entries
cardiovascular diseaseepilepsypsychotic disordersbipolar disorderpregnancyconcurrent serotonergic medications
Relative2 entries
hepatic impairmentconcurrent CYP2D6/CYP3A4 inhibitors
Dosage varies by body weight, tolerance & metabolism · Not medical advice · Terms

First synthesized in 2003 by Ralf Heim as part of a search for high-affinity serotonin receptor ligands, the compound was initially developed as a brain-imaging tracer designated CIMBI-5.[2] It appeared on the recreational drug market around 2010, sold as LSD on blotter paper — a misrepresentation that led to multiple deaths.[3] It is now Schedule I in the United States and controlled in most major jurisdictions worldwide.

Subjective effects include geometric visual patterns, color enhancement, synesthesia, euphoria, and accelerated thinking. The experience is defined by a heavy physical load — vasoconstriction, racing heart, and temperature dysregulation accompany the visuals at virtually every active dose, distinguishing it sharply from LSD and other classical psychedelics. Severe anxiety, confusion, agitation, and intense physical tension are characteristic unwanted effects.

25I-NBOMe does not produce physical dependence, but it carries critical acute toxicity risk — the margin between a psychoactive and potentially lethal dose is extremely narrow.[4] Multiple analytically confirmed deaths have involved seizures, dangerous overheating, muscle breakdown, and organ failure, and no dose can be considered reliably safe.[3] No clinical trials have been conducted — all human data come from forensic case reports and user self-reports.

History[edit]

Discovery

25I-NBOMe was first synthesized in 2003 by Ralf Heim, searching for compounds that bind serotonin receptors with high selectivity. It was subsequently developed as a brain-imaging tracer designated CIMBI-5 — used to visualize serotonin receptors in the living brain via PET scanning.[2] The Nichols laboratory later established key binding and activity data for the NBOMe series.[5]

Market emergence and fatalities

25I-NBOMe appeared on the recreational drug market around 2010, sold as a legal psychedelic alternative.[4] It was frequently distributed on blotter paper and deliberately sold as LSD.[6][3] Unlike LSD, which has no confirmed pharmacological fatalities at normal doses, 25I-NBOMe has an extremely narrow margin between active and toxic doses — users who believed they had taken LSD died as a result.

Prohibition

Fatalities prompted rapid international scheduling. In November 2013, the US Drug Enforcement Administration placed 25I-NBOMe in emergency Schedule I, citing 17 attributed deaths.[7] Permanent US scheduling followed in 2016,[8] and most major jurisdictions had acted by the same year.[9]

Chemistry[edit]

Structural class

25I-NBOMe belongs to the NBOMe series of substituted phenethylamines. The parent compound is 2C-I; adding an N-(2-methoxybenzyl) group to its terminal amine converts a modestly active compound into one of the most potent phenethylamine hallucinogens known.[4][10]

Its molecular formula is C₁₈H₂₂INO₃ (molecular weight 427.3 g/mol), and the 4-iodo group on the phenethylamine ring distinguishes it from related analogs 25C-NBOMe (4-chloro) and 25B-NBOMe (4-bromo).

Pharmacology[edit]

Mechanism of action

25I-NBOMe acts on serotonin receptors in the prefrontal cortex, producing its hallucinogenic effects.[4][10] It also binds adrenergic receptors — this drives the vasoconstriction, elevated blood pressure, and racing heart that accompany virtually every active dose.[1]

Pharmacokinetics

No controlled human studies exist. The primary route is sublingual or buccal — held under the tongue — because stomach acid breaks down the compound before it can be absorbed.[4][1] The liver extensively metabolizes it; the parent compound often disappears from urine, so forensic identification depends on specialized metabolite screening.[11][12]

Genetic variation in the liver enzyme responsible for most of its metabolism can cause major differences between individuals. Slow metabolizers may experience prolonged or more intense effects from the same dose.[13][14]

Neuroscience[edit]

Where it acts

25I-NBOMe activates serotonin receptors in the prefrontal cortex, triggering increased release of glutamate, dopamine, and serotonin.[15] This disrupts how the brain filters incoming sensory information, producing the visual distortions and loosened thinking of the psychedelic state. No human neuroimaging studies exist — the mechanistic picture comes entirely from animal models.

Why it matters

Whether 25I-NBOMe produces the beneficial neural rewiring documented for psilocybin and LSD is unknown. In rats, chronic use causes oxidative DNA damage and reduces the number of support cells in the prefrontal cortex[16] — raising the question of whether any neuroplastic benefit can be separated from harm.

Subjective Effects[edit]

Summary

The 25I-NBOMe experience is defined by two things happening at once: rich visual and perceptual effects overlaid on an insistent physical strain. Vasoconstriction, a racing heart, and temperature dysregulation are present at virtually every active dose — they are part of the experience, not adverse effects that can be avoided.

Compared to LSD, the body load is heavier and more pronounced, and the dose-safety margin is fundamentally different. Relative to its parent compound 2C-I, the NBOMe modification delivers the same phenethylamine character at a fraction of the dose, with a toxicological dimension that 2C-I does not share.

Effect Grid

Dose Level:
Description

At common doses (500–700 µg sublingual), the full psychedelic experience manifests: pronounced visual hallucinations including geometric patterning, color saturation and shifting, drifting and morphing of surfaces, and closed-eye visuals. Synesthesia becomes more likely. Time distortion is significant. Thought patterns shift markedly — novel associations, emotional intensification, and immersion in sensory experience are characteristic.

Physically, tachycardia, vasoconstriction (cold extremities), jaw tension, diaphoresis, and temperature dysregulation become common. Body load can be significant. Nausea during the come-up occurs in some individuals.

The experience commits the user to 6–10 hours of altered consciousness. Sleep is impossible during active effects. Functional impairment is substantial.

Modeled from the effect's dose-dependence curve — not per-substance measurements.

Perception(46)likelihood · intensity
Color enhancement
likely
Visual drifting
likely
Color alteration
likely
Environmental patterning
likely
Geometry
likely
Visual breathing
likely
Tracers
likely
Symmetrical texture repetition
likely
Double vision!
possible

Geometry · Visual breathing · Tracers · Symmetrical texture repetition · Brightness alteration · Visual morphing · Depth perception distortion · Perspective distortion · After-images · Music enhancement · Auditory enhancement · Peripheral misidentification · Visual diffraction · Auditory distortion · Light sensitivity · Peripheral vision distortion · Sound sensitivity · Spatial disorientation · Visual melting · Visual magnification · Auditory misinterpretation · Proprioceptive distortion · Touch enhancement · Vestibular distortion · Visual haze / noise · Visual acuity enhancement · Synesthesia · Touch suppression · Flashbacks · Object transformations · Internal hallucinations · Visual recursion · External hallucinations · Object activation · Environmental orbism / cubism · Visual processing suppression · Auditory hallucinations · Perspective hallucinations · Visual scenery slicing · Persisting hallucinations · Gustatory hallucination

Brightness alteration · Visual morphing · Depth perception distortion · Perspective distortion · After-images · Music enhancement · Auditory enhancement · Peripheral misidentification · Visual diffraction · Auditory distortion · Light sensitivity · Peripheral vision distortion · Sound sensitivity · Spatial disorientation · Visual melting · Visual magnification · Auditory misinterpretation · Proprioceptive distortion · Touch enhancement · Vestibular distortion · Visual haze / noise · Visual acuity enhancement · Synesthesia · Touch suppression · Flashbacks · Object transformations · Internal hallucinations · Visual recursion · External hallucinations · Object activation · Environmental orbism / cubism · Visual processing suppression · Auditory hallucinations · Perspective hallucinations · Visual scenery slicing · Persisting hallucinations · Gustatory hallucination

Body(39)likelihood · intensity
Stimulation
likely
Pupil dilation
likely
Vasoconstriction!
likely
Wakefulness
likely
Spontaneous body sensations
likely
Body high
likely
Appetite suppression
possible
Abnormal heartbeat!
possible
Motor control impairment!
possible

Spontaneous body sensations · Body high · Appetite suppression · Restlessness · Muscle tension · Insomnia · Physical fatigue · Tingling / electric sensations · Dehydration sensation · Dry mouth · Nausea · Headache · Dizziness · Heart rate perception changes · Vibrations / buzzing · Bodily lightness · Laughter fits · Bodily pressures · Body schema distortion · Breathing alteration · Excessive sweating · Motor control impairment · Tactile euphoria · Seizure threshold reduction · Sexual arousal enhancement · Temperature dysregulation · Involuntary body movements · Nasal congestion · Trembling · Increased urination · Bruxism · Respiratory stimulation · Vomiting · Tactile hallucination

Restlessness · Muscle tension · Insomnia · Physical fatigue · Tingling / electric sensations · Dehydration sensation · Dry mouth · Nausea · Headache · Dizziness · Heart rate perception changes · Vibrations / buzzing · Bodily lightness · Laughter fits · Bodily pressures · Body schema distortion · Breathing alteration · Excessive sweating · Tactile euphoria · Seizure threshold reduction · Sexual arousal enhancement · Temperature dysregulation · Involuntary body movements · Nasal congestion · Trembling · Increased urination · Bruxism · Respiratory stimulation · Vomiting · Tactile hallucination

Thinking(34)likelihood · intensity
Pattern recognition enhancement
likely
Novelty enhancement
likely
Aesthetic enhancement
likely
Thought connectivity
likely
Thought acceleration
possible
Conceptual thinking
possible
Suggestibility enhancement!
possible
Decision impairment!
possible
Amnesia!
v.rare

Thought connectivity · Thought acceleration · Conceptual thinking · Immersion enhancement · Cognitive euphoria · Cognitive impairment · Introspection enhancement · Openness enhancement · Memory suppression · Cognitive fatigue · Cognitive flexibility · Confusion · Multiple thought streams · Thought disorganization · Thought loops · Creativity enhancement · Humor enhancement · Analysis suppression · Focus suppression · Increased nature relatedness · Information processing suppression · Memory fragmentation · Synchronicity · Analysis enhancement · Cognitive dysphoria · Focus enhancement · Motivation enhancement · Amnesia · Delusions

Immersion enhancement · Cognitive euphoria · Cognitive impairment · Introspection enhancement · Openness enhancement · Memory suppression · Cognitive fatigue · Cognitive flexibility · Confusion · Multiple thought streams · Thought disorganization · Thought loops · Creativity enhancement · Humor enhancement · Analysis suppression · Focus suppression · Increased nature relatedness · Information processing suppression · Memory fragmentation · Synchronicity · Analysis enhancement · Cognitive dysphoria · Focus enhancement · Motivation enhancement · Delusions

Feeling(10)likelihood · intensity
Emotional enhancement
likely
Anxiety
possible
Emotional lability
possible
Euphoria
possible
Simultaneous emotions
possible
Empathy enhancement
possible
Dysphoria
possible
Irritability
possible
Paranoia!
possible

Simultaneous emotions · Empathy enhancement · Dysphoria · Irritability · Catharsis

Catharsis

Self(14)likelihood · intensity
Derealization
possible
Emotional susceptibility
possible
Depersonalization
possible
Disinhibition
possible
Sociability enhancement
possible
Communication suppression
possible
Social connection
possible
Trust enhancement
possible
Self-control suppression!
rare

Sociability enhancement · Communication suppression · Social connection · Trust enhancement · Communication enhancement · Boundary dissolution · Cognitive disconnection · Ego dissolution · Identity alteration

Communication enhancement · Boundary dissolution · Cognitive disconnection · Ego dissolution · Identity alteration

Time(5)likelihood · intensity
Time alteration
likely
Present-moment absorption
possible
Temporal disorientation
possible
Deja vu
possible
Jamais vu
possible
Transpersonal(6)likelihood · intensity
Unity and interconnectedness
possible
Existential realization
rare
Noetic insight
rare
Transpersonal feelings
v.rare
Transpersonal visions
v.rare
Entity contact
v.rare

Entity contact

Awareness(5)likelihood · intensity
Personal insight
possible
Cognitive dissonance
possible
Lucidity enhancement
possible
Reality testing impairment!
rare
Recursive awareness
rare
Likelihood: how common this effect is at the selected dose level.This effect has safety implications — review before use.

Timeline

Safety[edit]

Harm
Acute toxicity
Critical
Chronic toxicity
Moderate
Withdrawal
None
Tolerance buildup
rapid
Tolerance reset
14 days
Dependence
Physical
None
Psychological
Negligible
Compulsive redosing
Low
Dose escalation
Negligible
Cross-tol.
LSD · psilo · psilocin
Risk Shape
TOXPHYPSYWDRREDTOL

Toxicity

25I-NBOMe carries critical acute toxicity risk. The gap between a psychoactive dose and a potentially lethal dose is extremely narrow and not precisely known — unlike LSD, which has no confirmed pharmacological fatalities at normal doses, 25I-NBOMe has been causally linked to multiple analytically confirmed deaths.[3]

No lethal dose has been established in any species.

Acute toxicity

Severe intoxication presents with rapid heart rate, dangerously elevated blood pressure, high body temperature, dilated pupils, and heavy sweating. Neurological effects include severe agitation, disorientation, violent behavior, and generalized seizures.[4][1][17]

Life-threatening complications include muscle breakdown, acute kidney injury, blood clotting failure, organ failure, and cardiac arrest. Muscle breakdown is a common complication, driven by the combination of seizures, dangerous overheating, and vasoconstriction.[4]

Documented fatalities

Multiple analytically confirmed deaths have been attributed to 25I-NBOMe, with victims ranging from 15 to 21 years of age.[18][19][6][20][21] At DEA emergency scheduling in 2013, 17 deaths were attributed to 25I-NBOMe and two related NBOMe compounds collectively.[7]

Postmortem blood concentrations vary enormously and are unreliable as dose indicators due to redistribution from organs after death.[19][20] No validated fatal blood concentration threshold exists.

Neurotoxicity

In rats, chronic dosing produces oxidative DNA damage and reduces the number of support cells in the prefrontal cortex, though neuron counts remain unchanged at the same time points.[16] No human data exist, and whether single-dose or infrequent use produces comparable effects is unknown.

Misidentification risk

25I-NBOMe has been sold as LSD on blotter paper — directly contributing to multiple fatalities.[3] A bitter, metallic taste on blotter is a warning sign, as LSD is tasteless.[4] Ehrlich reagent provides more reliable identification: it reacts with LSD but produces no color change with NBOMe compounds.[4]

Psychological Risks

Acute psychological distress includes severe anxiety, panic, confusion, disorientation, and agitation. At higher doses, excited delirium — uncontrollable violent agitation and apparent insensitivity to pain — has been documented in multiple cases.[4][1][18]

No controlled data exist on persistent perceptual changes specific to 25I-NBOMe. Extended aftereffects lasting days have been reported by users but are not confirmed by controlled research.citation needed Triggering psychosis in predisposed individuals is expected based on the pharmacological class, but has not been systematically studied.

Tolerance & Dependence

Tolerance develops rapidly — in animal models, it is observable within 24 hours of a single dose.[22][23] Cross-tolerance exists with LSD, psilocin, DMT, mescaline, and other serotonin-acting psychedelics.[22]

25I-NBOMe does not produce physical dependence or withdrawal.[16] Tolerance half-life is estimated at approximately one week, with full reset at approximately two weeks; these values come from user self-reports and class inference.citation needed

Drug Interactions

Serotonergic agents

Combining 25I-NBOMe with other serotonergic drugs risks serotonin syndrome — a potentially life-threatening overheating and seizure response. Serotonin toxicity features were documented in a fatal case involving the closely related compound 25C-NBOMe.[24] SSRIs, SNRIs, MAOIs, MDMA, and tramadol all carry elevated risk.[1]

Tramadol is specifically dangerous: it has its own serotonergic activity, lowers the seizure threshold (as does 25I-NBOMe), and competes for the same liver enzyme.[13]

Stimulants and sympathomimetics

Cocaine and other stimulants add cardiovascular risk. Both cocaine and 25I-NBOMe cause vasoconstriction through separate mechanisms[1] — combined use creates additive risk for dangerously elevated blood pressure, arrhythmia, overheating, and seizures.inferred

Cannabis

THC has been detected alongside 25I-NBOMe in multiple fatal case reports.[21][18] No pharmacological interaction study exists. Cannabis may worsen anxiety, paranoia, and cardiovascular effects.

Metabolic interactions

25I-NBOMe is broken down by specific liver enzymes. Drugs that inhibit those enzymes — including certain antifungals and HIV medications — can increase 25I-NBOMe exposure significantly.[13][14] Individuals who are genetically slow at processing one of those enzymes face higher exposure from any given dose.

Contraindications

Cardiovascular disease, a personal or family history of psychotic disorders or bipolar disorder, and seizure disorders are all absolute contraindications. The compound's adrenergic activity stresses the heart;[1] psychedelic class effects can trigger psychosis in predisposed individuals; and 25I-NBOMe lowers the seizure threshold.[4]

Liver impairment and concurrent use of drugs that inhibit its metabolic enzymes are relative contraindications, as either could raise exposure unpredictably.[13][14] Pregnancy and breastfeeding are absolute contraindications given the absence of reproductive safety data and animal neurotoxicity findings.[16]

Harm Reduction[edit]

Forms & Identification

Reagent ResultsNot recorded+ add reagent results
AppearanceNot recorded+ add appearance
Red FlagsNot recorded+ add red flags

25I-NBOMe and LSD are both distributed on blotter paper and are visually indistinguishable. Ehrlich reagent reacts with LSD but produces no color change with NBOMe compounds — this single test can prevent the most dangerous misidentification in the current drug market.

A bitter, metallic, or numbing taste on blotter is a warning sign, since LSD is tasteless. Taste alone is not reliable and does not replace reagent testing.

Guidelines

  • Test every dose with Ehrlich and Hofmann reagent kits before use — this is the single most important risk reduction step for blotter-delivered substances
  • Start at the lowest reported threshold dose and do not redose — the slow, variable onset (up to two hours sublingual) has led to fatal redosing decisions
  • Use sublingual administration only — insufflation produces faster onset but sharper cardiovascular peaks
  • Never use alone — the risk of seizures, loss of consciousness, and excited delirium makes a sober sitter essential, not optional
  • Stay hydrated and in a cool environment — hyperthermia is a documented cause of death
  • Do not combine with stimulants, serotonergic drugs, or alcohol
  • Have a plan to contact emergency services before dosing

Set & Setting

The physical toxicity profile of 25I-NBOMe imposes constraints that set and setting cannot override. Classical psychedelics respond to environment and mindset — 25I-NBOMe produces dose-dependent cardiovascular stress regardless of surroundings.

A cool, temperature-controlled indoor environment with water and cooling access is essential. A sober, informed sitter who can monitor for physical warning signs — not just psychological distress — is strongly recommended.

Aftercare & integration. Extended aftereffects — including perceptual changes, mood instability, and physical fatigue — may persist for several days following use. Allow adequate rest and avoid demanding cognitive or physical tasks during the recovery window. Maintain hydration and balanced nutrition, particularly protein, to support recovery from any sub-clinical muscle stress.

If unusual perceptual symptoms (visual haze / noise, halos, trailing) persist beyond a week, consult a healthcare provider. For psychologically difficult experiences, processing with a trusted person or professional integration therapist may help contextualize the experience.

Recovery & Support

25I-NBOMe does not produce physical dependence, and compulsive use patterns have not been documented. If use has become a pattern despite awareness of the risks, this may reflect broader psychological factors worth exploring with a mental health professional.

Harm reduction organizations such as DanceSafe, The Loop, and local drug checking services provide non-judgmental support and testing resources.

Recovery resources, crisis lines, and support pathways → View all

Emergency Response

Recognizing an emergency: The line between an uncomfortable 25I-NBOMe experience and a medical emergency can shift rapidly. Seek immediate help if any of the following occur: seizures or convulsions, body temperature hot to the touch through clothing, chest pain or irregular heartbeat, uncontrollable violent agitation, loss of consciousness, dark or absent urine (a sign of muscle breakdown), or confusion so severe the person cannot communicate.

Immediate steps:

  • Call emergency services immediately — do not wait to see if symptoms improve
  • Place the person on their side (recovery position) if unconscious or seizing
  • Cool the person actively — remove excess clothing, apply cool water, move to a cooler environment
  • Do not restrain a person in excited delirium unless there is immediate danger of self-harm or harm to others
  • Do not induce vomiting

What to tell the dispatcher: Name the substance (25I-NBOMe or "NBOMe"), approximate amount and time taken, and current symptoms. Good Samaritan laws in many jurisdictions protect people who call for help during a drug emergency.

No reversal agent exists for 25I-NBOMe. Hospital treatment is supportive: benzodiazepines for seizures and agitation, active cooling for hyperthermia, IV fluids for muscle breakdown.

references

  1. [1] 
    ^abcdefghZawilska JB, Kacela M, Adamowicz P (2020) NBOMes-Highly Potent and Toxic Alternatives of LSD — Frontiers in Neuroscience doi:10.3389/fnins.2020.00078
  2. [2] 
    ^abEttrup A, Palner M, Gillings N, Santini MA, Hansen M, et al. (2010) Radiosynthesis and Evaluation of 11C-CIMBI-5 as a 5-HT2A Receptor Agonist Radioligand for PET. — Journal of Nuclear Medicine doi:10.2967/jnumed.109.074021
  3. [3] 
    ^abcdeNichols DE, Grob CS (2018) Is LSD toxic? — Forensic Science International doi:10.1016/j.forsciint.2018.01.006
  4. [4] 
    ^abcdefghijkHalberstadt AL (2017) Pharmacology and Toxicology of N-Benzylphenethylamine (NBOMe) Hallucinogens — Current Topics in Behavioral Neurosciences doi:10.1007/7854_2016_64
  5. [5] 
    ^Nichols DE, Sassano MF, Halberstadt AL, Klein LM, Brandt SD (2014) N-Benzyl-5-methoxytryptamines as Potent Serotonin 5-HT2 Receptor Family Agonists and Comparison with a Series of Phenethylamine Analogues — ACS Chemical Neuroscience doi:10.1021/cn500292d
  6. [6] 
    ^abShanks KG, Sozio T, Behonick GS (2015) Fatal Intoxications with 25B-NBOMe and 25I-NBOMe in Indiana During 2014. — Journal of Analytical Toxicology doi:10.1093/jat/bkv058