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25x-NBOMeLSD, psilocybin, DMT +5 moreLSD, psilocybin, DMT, mescaline, 25I-NBOMe, 25B-NBOMe, DOI, 2C-B show less
25C-NBOMe
4-chloro-2,5-dimethoxy-N-(2-methoxybenzyl)phenethylamine
25C-NBOMe — known as N-bomb or Smiles — is a synthetic psychedelic of the phenethylamine class. It is structurally derived from 2C-C with a single modification that increases potency by orders of magnitude.[1] It activates serotonin receptors in the brain,[2] disrupting sensory filtering and producing intense visual and perceptual changes.
25C-NBOMe is a synthetic psychedelic of the phenethylamine class. It is derived from 2C-C by addition of an N-benzylmethoxy group, a modification that increases potency by orders of magnitude.[1] 25C-NBOMe is a potent 5-HT₂A receptor agonist, producing its effects by activating serotonin signaling cascades that disrupt normal sensory filtering.[2]
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25x-NBOMeLSD, psilocybin, DMT +5 moreLSD, psilocybin, DMT, mescaline, 25I-NBOMe, 25B-NBOMe, DOI, 2C-B show less
The NBOMe series was first synthesized in 2003 by Ralf Heim during doctoral research into high-affinity serotonin receptor compounds.[3] By 2010–2011, it reached drug markets routinely sold as LSD — a deception made possible because both are active at microgram doses and look identical on blotter.[4] It is now Schedule I in the United States and controlled in multiple jurisdictions worldwide.[5]
Subjective effects include geometric visual patterns, brightened colors, accelerated thinking, emotional intensification, and strong physical stimulation. The experience has a sharp, electric visual quality — more angular and saturated than tryptamine psychedelics, and more physically intense, with less cognitive depth. Blood vessel constriction, jaw tension, temperature dysregulation, and anxiety are common unwanted effects.
25C-NBOMe produces no physical dependence,[6] but its acute toxicity is severe — fatal outcomes have been documented at recreational doses.[7] The dose-response curve is steep and poorly characterized, and combining it with stimulants or serotonergic drugs dramatically amplifies the risk of life-threatening toxicity. No controlled human studies exist; the evidence base rests entirely on fatal case reports and retrospective user accounts.
History[edit]
Discovery
The NBOMe structural modification was introduced by Ralf Heim in a 2003 doctoral dissertation, where he showed that adding an N-(2-methoxybenzyl) group to 2C-series compounds increased serotonin receptor binding by orders of magnitude.[3] A Copenhagen neuroimaging group later developed these compounds as brain imaging tools, assigning 25C-NBOMe the research designation Cimbi-82.[5]
Entry into drug markets
NBOMe compounds appeared on online drug markets between 2010 and 2011.[1][8] They were routinely sold as LSD — both are active at microgram doses and can be applied to blotter paper, making them visually indistinguishable.[4] As recently as 2024, a public drug warning was issued in Australia after 25C-NBOMe was found in samples sold as 2C-B.citation needed
Regulatory response
The U.S. Drug Enforcement Administration placed 25C-NBOMe into Schedule I on November 15, 2013,[5] with the order extended in 2015.[9] The United Kingdom classified all NBOMe compounds as Class A substances in June 2014.[10] Multiple additional jurisdictions enacted controls in the following years, driven by documented fatalities and emergency presentations.
The NBOMe class takes its name from its defining structural feature: the N-(2-methoxybenzyl) group, abbreviated "NBOMe." Street names include "N-bomb," "Smiles," "Solaris," and "Cimbi" — the last derived from the Copenhagen PET imaging program that developed these compounds for research.[11]
Chemistry[edit]
25C-NBOMe belongs to the NBOMe subclass of substituted phenethylamines.[1] Its parent compound is 2C-C, a member of the 2C-X series first synthesized by Alexander Shulgin; adding the N-(2-methoxybenzyl) group to the parent dramatically increases serotonin receptor binding affinity.[2][1]
The "25C" prefix identifies the chlorine atom at the 4-position of the ring, distinguishing it from the iodo and bromo variants of the series, which tend to be more potent.[12] Its molecular formula is C₁₈H₂₂ClNO₃ (molecular weight 335.8 g/mol), and the molecule contains no chirality centers.
Pharmacology[edit]
Mechanism of action
25C-NBOMe is a potent agonist at serotonin receptors.[1][2] Activating these receptors disrupts the brain's normal sensory filtering, producing the psychedelic state.[13] Despite its high binding strength, it behaves as a partial agonist — it activates the receptor less fully than its affinity alone would predict.[2]
Pharmacokinetics
Routes of administration
The primary route is sublingual or buccal — typically by holding blotter paper under the tongue.[1][4] Intranasal use produces a faster, more intense onset. Sublingual administration is preferred over oral ingestion, likely because it bypasses the liver's first processing of the drug.
Metabolism and detection
No controlled human pharmacokinetic data have been published for 25C-NBOMe. The primary breakdown pathway removes methoxy groups, followed by further modification and conjugation before excretion.[7][14][15][16] The compound does not appear on standard drug screens — detection requires specialized mass spectrometry.[17][4]
Neuroscience[edit]
Where it acts
No direct brain imaging or electrophysiology studies have been published for 25C-NBOMe. Based on its serotonin receptor activity, it is expected to trigger glutamate release in the prefrontal cortex — disrupting the brain's normal filtering of sensory input and producing the characteristic state of heightened perception and altered thinking.[13] Its partial agonist character[2] may reduce the magnitude of these effects compared to full agonists, though this has not been tested.
Why it matters
One framework proposes that psychedelics reduce the brain's confidence in its own predictions, letting raw sensory input dominate — consistent with the effects expected from 25C-NBOMe's receptor activity. Tolerance develops through downregulation: repeated activation causes the brain to reduce the number of available serotonin receptors, directly explaining why psychedelic effects diminish with repeated use.[18]
Several fundamental questions remain unanswered. Does 25C-NBOMe's partial agonist character produce a qualitatively distinct neural signature compared to full agonists like LSD? Does the compound promote growth of new neural connections, as observed with other serotonergic psychedelics?
Subjective Effects[edit]
The 25C-NBOMe experience is dominated by visual intensity — a sharp, electric quality that users describe as angular and saturated rather than the organic, flowing geometry of tryptamine psychedelics. Physical stimulation is a defining feature, running throughout the experience and coloring the entire state.
Compared to LSD, the experience carries heavier body effects and a narrower subjective quality — more sensory intensity, less cognitive depth. Compared to its parent compound 2C-C, the NBOMe modification produces a dramatically more intense stimulant component alongside the visual effects.
The NBOMe series was first synthesized in 2003 by Ralf Heim as part of doctoral research into high-affinity serotonin receptor ligands.[3] 25C-NBOMe entered recreational markets around 2010–2011, frequently sold on blotter paper misrepresented as LSD.[4] It is now a Schedule I substance in the United States and is controlled in multiple jurisdictions worldwide.[5]
Subjective effects include geometric visual patterns, color enhancement, thought acceleration, and emotional intensification. The experience is defined by sharp, electric visual intensity and pronounced physical stimulation — a sensory-dominant state with less cognitive depth than classical tryptamine psychedelics. Vasoconstriction, jaw tension, temperature dysregulation, and anxiety are characteristic unsought effects.
25C-NBOMe produces no physical dependence,[6] but its acute toxicity profile is critical — fatal outcomes have been documented at recreational doses.[7] The dose-response curve is steep and poorly characterized, with tolerance developing rapidly through downregulation[8] but offering no protection against the compound's life-threatening physical toxicity.[1] No controlled human studies have been conducted; the current understanding rests entirely on fatal case reports and retrospective user accounts.
History[edit]
Discovery
The NBOMe structural modification was introduced by Ralf Heim in a 2003 doctoral dissertation at the Free University of Berlin, where he demonstrated that appending an N-(2-methoxybenzyl) group to 2C-series phenethylamines increased serotonin receptor binding affinity by orders of magnitude.[3] The Copenhagen neuroimaging group subsequently developed NBOMe compounds as PET radioligands for brain imaging, assigning 25C-NBOMe the research designation Cimbi-82.[5] The related compound 25I-NBOMe was radiolabeled and validated as the first agonist PET tracer for the 5-HT₂A receptor.[9]
Entry into drug markets
NBOMe compounds appeared on online research chemical markets between 2010 and 2011.[1][10] A defining feature of their market presence was systematic misrepresentation as LSD: both compound classes are active at microgram doses and can be applied to blotter paper, making visual distinction impossible.[4] Analytical testing of seized samples confirmed 25C-NBOMe alongside 25I-NBOMe and 25B-NBOMe, sometimes with multiple analogs on a single piece of blotter.[4] As recently as 2024, a public drug warning was issued in Victoria, Australia, after 25C-NBOMe was found in samples sold as 2C-B.citation needed
Regulatory response
The U.S. Drug Enforcement Administration placed 25C-NBOMe, 25I-NBOMe, and 25B-NBOMe into Schedule I on November 15, 2013,[5] with the temporary order extended in 2015.[11] The United Kingdom classified all NBOMe compounds as Class A substances in June 2014.[12] Multiple additional jurisdictions enacted controls in the following years, driven by documented fatalities and emergency presentations.
The NBOMe class takes its name from its defining structural feature: the N-(2-methoxybenzyl) group, abbreviated as "NBOMe." Street names include "N-bomb," "Smiles," "Solaris," and "Cimbi" — the last derived from the Copenhagen PET imaging program that developed these compounds for research.[13] The "25C" prefix identifies the 4-chloro variant within the series, following a naming convention where 25 denotes the NBOMe scaffold and the letter specifies the 4-position substituent.
Chemistry[edit]
Structural class
25C-NBOMe belongs to the NBOMe (N-benzylmethoxy) subclass of substituted phenethylamines. Its parent compound is 2C-C (2,5-dimethoxy-4-chlorophenethylamine), a member of the 2C-X series first synthesized by Alexander Shulgin.[1] The defining structural feature of the NBOMe class is the N-(2-methoxybenzyl) group attached to the amine nitrogen — an addition that dramatically increases 5-HT₂A receptor binding affinity relative to the unsubstituted parent.[2][1]
The "25C" designation refers to the chlorine atom at the 4-position of the phenyl ring, distinguishing this compound from 25I-NBOMe (iodo), 25B-NBOMe (bromo), and other congeners. The identity of the 4-position halogen modulates both receptor affinity and potency across the series, with iodo and bromo variants generally exceeding the chloro form.[14]
Molecular identity
| Molecular formula | C₁₈H₂₂ClNO₃ |
| Molecular weight | 335.8 g/mol |
The molecule comprises a 2,5-dimethoxyphenethylamine core bearing a chlorine atom at the 4-position, connected via the amine nitrogen to a 2-methoxybenzyl group. Three methoxy groups are present: two on the phenethylamine ring (positions 2 and 5) and one on the N-benzyl ring (position 2). These methoxy groups serve as primary sites for metabolic breakdown.[7]
Stereochemistry
25C-NBOMe contains no chirality centers. The compound exists as a single achiral species with no stereoisomeric forms.
Physical properties
No published data characterize the melting point, solubility, or stability of 25C-NBOMe in free base or salt forms. The compound is typically encountered as a hydrochloride salt applied to blotter paper or, less commonly, as a powder.[4]
Pharmacology[edit]
Mechanism of action
25C-NBOMe is a potent agonist at serotonin 5-HT₂A and 5-HT₂C receptors.[1][2] Its psychedelic effects are driven primarily through 5-HT₂A receptor activation, which triggers a signaling cascade that alters sensory processing and perception.[15]
The N-(2-methoxybenzyl) group is responsible for the compound's dramatically increased receptor binding relative to its parent compound 2C-C.[2][1] Despite this high binding affinity, functional studies show that 25C-NBOMe behaves as a partial agonist — it binds strongly but activates the receptor less fully than its binding strength would predict.[2]
Biased agonism profiling across the broader NBOMe class provides context for understanding how these compounds selectively activate different signaling pathways at the 5-HT₂A receptor.[16]
Pharmacokinetics
No controlled human pharmacokinetic study has been published for 25C-NBOMe. The available data derive from a single fatal case report and animal studies of structural analogs.
Routes of administration
The primary route is sublingual or buccal, typically via blotter paper.[1][4] Intranasal insufflation has also been reported and produces a faster, more intense onset. Sublingual administration is preferred over oral ingestion, presumably to bypass first-pass liver metabolism.
Absorption and distribution
Sublingual onset is reported at 0–15 minutes based on user consensus.citation needed The only published human blood concentration data come from a fatal case, with drug detected in blood, urine, vitreous humor, and liver tissue.[7] No plasma half-life has been determined.
Brain penetration data from a related NBOMe compound in rats show peak brain tissue concentration at 60 minutes following injection, with detectable brain levels persisting at 8 hours.[17]
Metabolism
Metabolic data specific to 25C-NBOMe come from a single fatal case, in which a demethylated and glucuronidated metabolite was identified in urine and blood.[7] Broader NBOMe-class studies using human liver preparations identify O-demethylation as the primary metabolic pathway, followed by hydroxylation, N-dealkylation, and glucuronide conjugation.[18][19][20]
The specific liver enzymes responsible for 25C-NBOMe metabolism have not been identified; data from 25I-NBOMe suggest involvement of multiple CYP450 enzymes.[21]
Detection
25C-NBOMe does not trigger standard drug screening tests. Confirmatory detection requires specialized mass spectrometry techniques.[22][4]
Neuroscience[edit]
Where it acts
No direct neuroimaging or electrophysiology studies have been published for 25C-NBOMe. Based on its serotonin 2A receptor agonist profile, the compound is expected to trigger glutamate release from deep-layer neurons in the prefrontal cortex, disrupting the brain's normal filtering of sensory information and producing the characteristic psychedelic state of heightened perception and altered cognition.[15]
Its partial agonist character at 5-HT₂A[2] may modulate the magnitude of these neural effects compared to full agonists, though this has not been empirically tested.
Why it matters
The REBUS model proposes that psychedelics reduce the brain's confidence in its existing expectations, allowing raw sensory input to dominate — a framework consistent with the perceptual effects expected from 25C-NBOMe's receptor activity. Tolerance develops rapidly through 5-HT₂A downregulation, a process that is activation-dependent,[8] directly explaining why psychedelic effects diminish with repeated dosing across all serotonergic psychedelics.
Several fundamental questions remain unanswered. Does 25C-NBOMe's partial agonist character produce a qualitatively distinct neural signature compared to full agonists like LSD? Does the compound promote neuroplasticity — the growth of new neural connections — as observed with other serotonergic psychedelics?
Subjective Effects[edit]
The 25C-NBOMe experience is characterized by pronounced stimulation and a visual field that users consistently describe as "sharp" or "electric" — more angular and saturated than the organic, flowing geometry of tryptamine psychedelics. At lower doses the experience centers on visual enhancement and mild euphoria; at higher doses it intensifies into full perceptual distortion with heavy somatic load. Set and setting exert strong influence on emotional trajectory: the same dose can produce wonder or escalating anxiety depending on environment and psychological preparation.[1]
Compared to LSD, the experience carries heavier body effects — vasoconstriction, jaw tension, temperature dysregulation — and a narrower subjective quality with more sensory intensity and less cognitive depth. Compared to its parent compound 2C-C, 25C-NBOMe operates at microgram rather than milligram doses, with a correspondingly more pronounced sympathomimetic component and less room for dosing error.[2]
Effect Grid
At common doses (300–700 µg sublingual), the full psychedelic experience manifests. Pronounced open-eye visuals include geometric patterning overlaid on surfaces, color shifting and saturation, environmental drifting and morphing, and tracers behind moving objects. Closed-eye visuals feature complex geometry and vivid imagery. Time distortion becomes significant. Thought connectivity increases dramatically, producing novel associations; thought loops and conceptual confusion may occur. Emotional intensification is pronounced — music, nature, and social interactions can feel profoundly meaningful or overwhelming depending on set and setting.
Physically, stimulation is prominent. Jaw tension, body load, vasoconstriction (cold hands and feet), temperature dysregulation, and difficulty urinating are common. Nausea and muscle tension occur in a subset of users.
This is a significant commitment: the experience lasts 8–10 hours with residual effects persisting beyond. Sleep is impossible for at least 8 hours. The steep dose-response curve means small increases within this range can produce disproportionately stronger effects.
Modeled from the effect's dose-dependence curve — not per-substance measurements.
Tracers · Music enhancement · Brightness alteration · Environmental patterning · Light sensitivity · Peripheral vision distortion · Perspective distortion · Visual breathing · Visual morphing · Symmetrical texture repetition · Auditory distortion · Auditory enhancement · Depth perception distortion · Sound sensitivity · Visual melting · Visual diffraction · Vestibular distortion · After-images · Peripheral misidentification · Spatial disorientation · Touch enhancement · Visual haze / noise · Synesthesia · Visual acuity enhancement · Auditory misinterpretation · Holotropic state · Proprioceptive distortion · Visual processing acceleration · Visual magnification · Olfactory enhancement · Taste enhancement · Touch suppression · Flashbacks · Object transformations · Internal hallucinations · External hallucinations · Visual recursion · Environmental orbism / cubism · Object activation · Visual scenery slicing · Auditory hallucinations · Visual flipping · Perspective hallucinations · Shadow people · Gustatory hallucination · Persisting hallucinations
Light sensitivity · Peripheral vision distortion · Perspective distortion · Visual breathing · Visual morphing · Symmetrical texture repetition · Auditory distortion · Auditory enhancement · Depth perception distortion · Sound sensitivity · Visual melting · Visual diffraction · Vestibular distortion · After-images · Peripheral misidentification · Spatial disorientation · Touch enhancement · Visual haze / noise · Synesthesia · Visual acuity enhancement · Auditory misinterpretation · Holotropic state · Proprioceptive distortion · Visual processing acceleration · Visual magnification · Olfactory enhancement · Taste enhancement · Touch suppression · Flashbacks · Object transformations · Internal hallucinations · External hallucinations · Visual recursion · Environmental orbism / cubism · Object activation · Visual scenery slicing · Auditory hallucinations · Visual flipping · Perspective hallucinations · Shadow people · Gustatory hallucination · Persisting hallucinations
Body scan awareness · Muscle tension · Appetite suppression · Dry mouth · Body high · Heart rate perception changes · Spontaneous body sensations · Restlessness · Excessive sweating · Insomnia · Physical fatigue · Tingling / electric sensations · Vibrations / buzzing · Nausea · Dehydration sensation · Headache · Bruxism · Dizziness · Tactile euphoria · Temperature dysregulation · Bodily lightness · Abnormal heartbeat · Bodily pressures · Body schema distortion · Laughter fits · Nystagmus (eye wobbles) · Sexual arousal enhancement · Seizure threshold reduction · Breathing alteration · Involuntary body movements · Respiratory stimulation · Trembling · Increased urination · Pain enhancement · Vomiting · Tactile hallucination · Bodily dissociation
Dry mouth · Body high · Heart rate perception changes · Spontaneous body sensations · Restlessness · Excessive sweating · Insomnia · Physical fatigue · Tingling / electric sensations · Vibrations / buzzing · Nausea · Dehydration sensation · Headache · Bruxism · Dizziness · Tactile euphoria · Bodily lightness · Abnormal heartbeat · Bodily pressures · Body schema distortion · Laughter fits · Nystagmus (eye wobbles) · Sexual arousal enhancement · Seizure threshold reduction · Breathing alteration · Involuntary body movements · Respiratory stimulation · Trembling · Increased urination · Pain enhancement · Vomiting · Tactile hallucination · Bodily dissociation
Aesthetic enhancement · Thought acceleration · Conceptual thinking · Introspection enhancement · Multiple thought streams · Openness enhancement · Thought connectivity · Memory suppression · Cognitive euphoria · Cognitive flexibility · Cognitive impairment · Thought loops · Creativity enhancement · Humor enhancement · Cognitive dysphoria · Cognitive fatigue · Confusion · Focus suppression · Information processing suppression · Memory fragmentation · Synchronicity · Thought disorganization · Analysis enhancement · Language suppression · Analysis suppression · Compulsive redosing urge · Focus enhancement · Information processing enhancement · Delusions of sobriety · Amnesia · Delirium · Delusions
Introspection enhancement · Multiple thought streams · Openness enhancement · Thought connectivity · Memory suppression · Cognitive euphoria · Cognitive flexibility · Cognitive impairment · Thought loops · Creativity enhancement · Humor enhancement · Cognitive dysphoria · Cognitive fatigue · Confusion · Focus suppression · Information processing suppression · Memory fragmentation · Synchronicity · Thought disorganization · Analysis enhancement · Language suppression · Analysis suppression · Focus enhancement · Information processing enhancement · Delusions of sobriety · Amnesia · Delirium · Delusions
Anxiety · Simultaneous emotions · Empathy enhancement · Dysphoria · Catharsis · Irritability · Mania
Dysphoria · Catharsis · Irritability
Disinhibition · Social connection · Sociability enhancement · Communication suppression · Social disconnection · Trust enhancement · Communication enhancement · Flow state · Ego inflation · Sociability suppression · Boundary dissolution · Cognitive disconnection · Identity alteration · Ego dissolution · Telepathic feelings
Social disconnection · Trust enhancement · Communication enhancement · Flow state · Ego inflation · Sociability suppression · Boundary dissolution · Cognitive disconnection · Identity alteration · Ego dissolution · Telepathic feelings
Entity contact · Non-dual awareness · Near-death experience
Timeline
First alerts appear within 5–15 minutes: a chemical taste from the blotter, subtle body awareness, and faint brightening of the visual field. Effects are easily overlooked at threshold doses.
Rising intensity over 15–45 minutes. Stimulation builds, colors sharpen, and the first visual distortions appear. Anxiety or excitement is common during this transitional phase.
Maximum intensity sustained for 3–4 hours. Visual geometry, color enhancement, environmental drifting, and time distortion are at their strongest. Thought acceleration and emotional intensification dominate the cognitive landscape.
A sustained period of 2–3 hours at reduced but still significant intensity. Visuals soften but persist. Cognitive clarity gradually returns.
Gradual return toward baseline over 1–2 hours. Visual effects fade to subtle enhancements. Mental fatigue and residual stimulation coexist.
Residual effects persist for 4–12 hours: mild mood elevation or flatness, subtle visual brightness, and physical fatigue. Cognitive processing may feel slightly altered. Sleep quality is often poor even after the subjective experience has ended.
Safety[edit]
- Acute toxicity
- Critical
- Chronic toxicity
- Moderate
- Withdrawal
- None
- Tolerance buildup
- rapid
- Tolerance reset
- 14 days
- Physical
- None
- Psychological
- Low
- Compulsive redosing
- Negligible
- Dose escalation
- Negligible
- Cross-tol.
- LSD · psilo · DMT
Toxicity
Acute toxicity
25C-NBOMe has a critical acute toxicity profile. The margin between common recreational doses (300–700 µg sublingual) and doses associated with fatal outcomes is unknown and presumed narrow.[7] The first confirmed fatal poisoning involved a young man who died approximately 12 hours after ingestion, with preceding signs of severe serotonin-related toxicity.[7]
25C-NBOMe has a steep and poorly characterized dose-response curve. Fatal outcomes have been documented at recreational doses. The dose values listed in this article are derived from user reports, not controlled studies, and do not establish a safe dose ceiling.
- Neuropsychiatric: hallucinations, severe agitation, violent behavior, excited delirium, seizures
- Cardiovascular: dilated pupils, rapid heart rate, high blood pressure, elevated body temperature, heavy sweating
- Serious complications: muscle breakdown (linked to seizures and elevated body temperature[21]), blood clotting dysfunction, dangerously low blood sugar, organ failure[1]
Severe agitation and seizures have been reported lasting up to three days.[4]
Management of acute toxicity
Based on published case series[19][1]:
- Benzodiazepines are the first-line treatment for agitation and seizures; high doses may be required
- Active cooling is critical — elevated body temperature drives muscle breakdown and kidney failure
- Supportive care targeting presenting symptoms; no specific antidote exists
- Standard drug screens do not detect NBOMe compounds — confirmatory laboratory testing is required[17][4]
Psychological risks
Severe psychological distress — including panic, paranoia, and psychotic episodes — is documented across the NBOMe class.[1][20] Prolonged psychotic episodes and excited delirium lasting days have been reported.[4] Persistent visual disturbances following use — patterns or colors that linger long after the experience ends — are a risk consistent with serotonergic psychedelics generally.citation needed
The steep dose-response curve, frequent misrepresentation as LSD, and variable blotter dosing mean users may unknowingly take far more than expected — compounding psychological risk.
Tolerance and dependence
Tolerance develops quickly through downregulation: the brain reduces the number of available serotonin receptors in response to repeated activation.[18] User reports estimate tolerance half-life at approximately 7 days, with full reset at 14 days.[22]
Full cross-tolerance exists with all serotonin-agonist psychedelics, including LSD, psilocybin, DMT, mescaline, and all other NBOMe compounds.[18] No physical dependence or withdrawal has been documented.[6]
Drug Interactions
Serotonergic drugs are the most dangerous interaction class. Taking 25C-NBOMe alongside SSRIs, SNRIs, MAOIs, or tramadol can trigger serotonin syndrome — a potentially life-threatening overheating, muscle spasm, and seizure response. Tramadol poses a double risk: it raises serotonin and lowers the seizure threshold, both of which are already features of NBOMe toxicity.[1]inferred
Stimulants like cocaine or amphetamines add cardiovascular strain on top of 25C-NBOMe's vasoconstriction, creating compounded risk of severe blood pressure elevation, irregular heartbeat, and stroke.[1]inferred The confirmed fatal case involved co-ingestion of amphetamine.[7]
MDMA adds serotonergic burden and elevated body temperature risk. Cannabis may unpredictably intensify psychedelic effects and anxiety. Polydrug use involving NBOMes with serotonergic substances increases the risk of severe adverse outcomes.[6]
Contraindications
7 knownNo substance-specific contraindication studies exist. The following are inferred from 25C-NBOMe's pharmacological and toxicological profile:
- Heart conditions — severe blood vessel constriction and blood pressure elevation create direct cardiovascular danger
- Seizure disorders — NBOMe compounds lower seizure threshold; seizures are a documented feature of acute toxicity[1]
- Serotonergic medications — SSRIs, SNRIs, MAOIs, tramadol: risk of serotonin syndrome
- Concurrent stimulant use — cocaine, amphetamines: additive cardiovascular toxicity
- Personal or family history of psychotic disorders — serotonin receptor activation may precipitate or worsen psychosis
- Pregnancy — no safety data exist; effects on fetal development are unknownsafety citation needed
Harm Reduction[edit]
Forms & Identification
The primary risk with 25C-NBOMe is unknowing exposure: it is routinely sold as LSD on blotter paper, and the two are visually indistinguishable.[4] A bitter, numbing taste on the tongue strongly suggests an NBOMe compound — LSD is tasteless. Reagent testing helps but cannot definitively confirm identity; drug checking services using mass spectrometry provide the most reliable confirmation.
Guidelines
- Test every sample before use — reagent kits provide preliminary identification, but professional drug checking services are strongly recommended for NBOMe-class compounds
- Start with the lowest reported active dose and wait at least 90 minutes before considering redosing — the dose-response curve is steep and unpredictable
- Never use alone; a sober, informed sitter should be present throughout
- Ensure the environment is temperature-controlled — elevated body temperature is a hallmark of NBOMe toxicity
- Stay hydrated but avoid excessive water intake
- Have benzodiazepines available for managing anxiety or agitation if accessible
Set & Setting
Set and setting exert an outsized influence on the 25C-NBOMe experience. Pronounced stimulation and a steep dose-response curve mean anxiety or uncomfortable environments can rapidly escalate into distressing psychological states. A calm, familiar space with temperature control, water access, and a trusted sober companion substantially reduces the risk of panic and dangerous behavior.
Aftercare & integration. The stimulant load and long duration of 25C-NBOMe can leave users physically exhausted. Prioritize sleep, hydration, and light nutrition in the 24 hours following use. Physical discomfort — jaw tension, headache, residual vasoconstriction — may persist into the following day.
Psychologically intense experiences benefit from deliberate processing: writing about the experience, discussing it with a trusted person, or seeking professional support if distressing effects persist beyond 48 hours. Persistent visual disturbances, anxiety, or depersonalization warrant professional consultation.
Recovery & Support
While 25C-NBOMe does not produce physical dependence, repeated use despite negative consequences — particularly among individuals using it unknowingly as LSD — may indicate a broader pattern of substance misuse. Community harm reduction organizations, psychedelic peer support services, and mental health professionals experienced with substance-related issues can provide support. The Fireside Project (62-FIRESIDE / 623-473-7433) offers free psychedelic peer support.
Recovery resources, crisis lines, and support pathways → View all
Emergency Response
Recognizing an emergency: Seek immediate medical help if any of the following occur: seizures, loss of consciousness, chest pain, body temperature hot to the touch, uncontrollable agitation or violent behavior, confusion lasting more than several hours, or difficulty breathing.
Immediate steps:
- 1. Call emergency services immediately — do not wait to see if symptoms improve
- 2. Move the person to a cool environment and apply cold compresses to neck, armpits, and groin
- 3. If unconscious but breathing, place them in the recovery position (on their side)
- 4. Do not restrain them unless they are in immediate danger of harming themselves
- 5. Do not induce vomiting
What to tell the dispatcher: Name the substance (25C-NBOMe or "an NBOMe compound"), approximate amount and time of ingestion, current symptoms, and any other substances taken. Good Samaritan laws in many jurisdictions protect people who call for help during a drug emergency.
No reversal agent exists for NBOMe toxicity. Treatment is supportive — benzodiazepines for agitation and seizures, active cooling for elevated body temperature.
Legal Status[edit]
25C-NBOMe is controlled in the most restrictive scheduling category in multiple major jurisdictions, driven by documented fatalities and emergency presentations associated with the NBOMe class.
| Jurisdiction | Classification | Key provisions |
|---|---|---|
| United States | Schedule I (Controlled Substances Act) | Temporarily placed November 15, 2013 alongside 25I-NBOMe and 25B-NBOMe;[5] extended 2015;[9] permanent scheduling followedcitation needed |
| United Kingdom | Class A (Misuse of Drugs Act 1971) | Temporary control June 2013; permanent Class A from June 2014[10] |
| Canada | Schedule III (Controlled Drugs and Substances Act) | Controlled from October 12, 2016[10] |
| Brazil | Controlled substance | Listed February 18, 2014[10] |
| Russia | Controlled substance | Listed October 2011[10] |
| Israel | Controlled substance | Listed May 2013[10] |
| Sweden | Controlled substance | Listed August 1, 2013 (unconfirmed)[10] |
| Australia | Status unconfirmed | Likely controlled under analog provisions or state-level drug laws; 25C-NBOMe circulates in Australian drug markets as of 2024citation needed |
Legal status changes frequently and varies by jurisdiction. This table reflects available information and is not legal advice.
Safety[edit]
- Acute toxicity
- Critical
- Chronic toxicity
- Moderate
- Withdrawal
- None
- Tolerance buildup
- rapid
- Tolerance reset
- 14 days
- Physical
- None
- Psychological
- Low
- Compulsive redosing
- Negligible
- Dose escalation
- Negligible
- Cross-tol.
- LSD · psilo · DMT
Toxicity
Acute toxicity
25C-NBOMe presents a critical acute toxicity profile. The margin between common recreational doses (300–700 µg sublingual) and doses associated with fatal outcomes is unknown and presumed narrow.[7] No lethal dose has been established in any species. No therapeutic index has been defined.
The first fatal poisoning with quantitative confirmation involved a young male who died approximately 12 hours after ingestion, with preceding signs of serotonin syndrome; amphetamine was also detected in his blood.[7] Additional severe intoxications have been analytically confirmed.[23]
- Neuropsychiatric: hallucinations, severe agitation, violent behavior, excited delirium, seizures
- Cardiovascular: dilated pupils, rapid heart rate, high blood pressure, elevated body temperature, heavy sweating
- Serious complications: muscle breakdown (linked to seizures and elevated body temperature[26]), blood clotting dysfunction, dangerously low blood sugar, organ failure[1]
Severe agitation, bizarre behavior, and seizures persisting for up to three days have been reported for the NBOMe class.[4]
25C-NBOMe has a steep and poorly characterized dose-response curve. Fatal outcomes have been documented at recreational doses. The dose values listed in this article are derived from user reports, not controlled studies, and do not establish a safe dose ceiling.
Management of acute toxicity
Based on published case series[24][1]:
- Benzodiazepines are the first-line treatment for agitation and seizures; high doses may be required
- Active cooling is critical — elevated body temperature drives muscle breakdown and kidney failure
- Supportive care targeting presenting symptoms; no specific antidote exists
- Standard drug screens do not detect NBOMe compounds — confirmatory laboratory testing is required[22][4]
Psychological risks
Severe psychological distress — including panic, paranoia, and psychotic episodes — is documented across the NBOMe class.[1][25] Prolonged psychotic episodes and excited delirium lasting days have been reported.[4] The risk of HPPD (HPPD) is consistent with class effects of serotonergic psychedelics.citation needed
The steep dose-response curve, frequent misrepresentation as LSD, and variable blotter dosing create conditions where users may unknowingly take doses far exceeding their expectations — compounding psychological risk.
Tolerance and dependence
Tolerance develops rapidly through 5-HT₂A downregulation, an activation-dependent process.[8] User reports estimate tolerance half-life at approximately 7 days, with full reset at 14 days — consistent with receptor recovery timelines observed for LSD in animal models.[27]
Full cross-tolerance exists with all 5-HT₂A agonist psychedelics, including LSD, psilocybin, DMT, mescaline, and all other NBOMe compounds.[8] No cross-tolerance develops with non-psychedelic compounds.[8]
No physical dependence or withdrawal has been documented. Serotonergic psychedelics lack the mesolimbic pathway activation associated with compulsive use.[6]
Drug Interactions
No controlled interaction studies exist for 25C-NBOMe. The following assessments are mechanism-inferred from its pharmacological profile.
Serotonergic drugs represent the most dangerous interaction class. Co-administration with SSRIs, SNRIs, MAOIs, or tramadol creates risk of serotonin syndrome. Tramadol poses a dual risk: serotonin syndrome compounded by seizure threshold reduction, both of which independently feature in the NBOMe toxicity pattern.[1]inferred
Stimulants (cocaine, amphetamines) produce additive cardiovascular strain. 25C-NBOMe-mediated vasoconstriction combined with stimulant effects creates compounded risk of severe blood pressure elevation, heart rhythm disturbances, and stroke.[1]inferred The confirmed fatal case involved co-ingestion of amphetamine.[7]
Polydrug use involving NBOMes with other serotonergic substances is documented as increasing risk of severe adverse outcomes.[6]
Cannabis may unpredictably intensify psychedelic effects and anxiety. MDMA adds serotonergic burden and elevated body temperature risk. No pharmacological data characterize either interaction.
Contraindications
7 knownNo substance-specific contraindication studies exist. The following are inferred from 25C-NBOMe's pharmacological and toxicological profile:
- Heart conditions — severe blood vessel constriction and blood pressure elevation create direct cardiovascular danger
- Seizure disorders — NBOMe compounds lower seizure threshold; seizures are a documented feature of acute toxicity[1]
- Serotonergic medications — SSRIs, SNRIs, MAOIs, tramadol: risk of serotonin syndrome
- Concurrent stimulant use — cocaine, amphetamines: additive cardiovascular toxicity
- Personal or family history of psychotic disorders — 5-HT₂A agonism may precipitate or worsen psychosis
- Pregnancy — no safety data exist; effects on fetal development are unknownsafety citation needed
Harm Reduction[edit]
Forms & Identification
The primary risk with 25C-NBOMe is unknowing exposure: the compound is frequently sold as LSD on blotter paper, and the two are visually indistinguishable.[4] A bitter, numbing taste on the tongue is a strong indicator that a blotter contains an NBOMe compound rather than LSD, which is tasteless. Reagent testing can help differentiate the two, but no field test provides definitive identification — mass spectrometry-based drug checking services offer the most reliable confirmation.
Guidelines
- Test every sample before use — reagent kits provide preliminary identification, but professional drug checking services are strongly recommended for NBOMe-class compounds
- Start with the lowest reported active dose and wait at least 90 minutes before considering redosing — the dose-response curve is steep and unpredictable
- Never use alone; a sober, informed sitter should be present throughout
- Ensure the environment is temperature-controlled — elevated body temperature is a hallmark of NBOMe toxicity
- Stay hydrated but avoid excessive water intake
- Have benzodiazepines available for managing anxiety or agitation if accessible
Set & Setting
Set and setting exert an outsized influence on 25C-NBOMe experiences. The compound's pronounced stimulation and steep dose-response curve mean that anxiety or uncomfortable environments can rapidly escalate into distressing psychological states. A calm, familiar environment with access to water, comfortable temperature control, and a trusted sober companion substantially reduces the risk of panic and dangerous behavior.
Aftercare & integration. The stimulant load and long duration of 25C-NBOMe can leave users physically exhausted. Prioritize sleep, hydration, and light nutrition in the 24 hours following use. Physical discomfort — jaw tension, headache, residual vasoconstriction — may persist into the following day.
Psychologically intense experiences benefit from deliberate processing: writing about the experience, discussing it with a trusted person, or seeking professional support if distressing effects persist beyond 48 hours. Persistent visual disturbances, anxiety, or depersonalization warrant professional consultation.
Recovery & Support
While 25C-NBOMe does not produce physical dependence, repeated use despite negative consequences — particularly among individuals using it unknowingly as LSD — may indicate a broader pattern of substance misuse. Community harm reduction organizations, psychedelic peer support services, and mental health professionals experienced with substance-related issues can provide support. The Fireside Project (62-FIRESIDE / 623-473-7433) offers free psychedelic peer support.
Recovery resources, crisis lines, and support pathways → View all
Emergency Response
Recognizing an emergency: Seek immediate medical help if any of the following occur: seizures, loss of consciousness, chest pain, body temperature hot to the touch, uncontrollable agitation or violent behavior, confusion lasting more than several hours, or difficulty breathing.
Immediate steps:
- 1. Call emergency services immediately — do not wait to see if symptoms improve
- 2. Move the person to a cool environment and apply cold compresses to neck, armpits, and groin
- 3. If unconscious but breathing, place them in the recovery position (on their side)
- 4. Do not restrain them unless they are in immediate danger of harming themselves
- 5. Do not induce vomiting
What to tell the dispatcher: Name the substance (25C-NBOMe or "an NBOMe compound"), approximate amount and time of ingestion, current symptoms, and any other substances taken. Good Samaritan laws in many jurisdictions protect people who call for help during a drug emergency.
No reversal agent exists for NBOMe toxicity. Treatment is supportive — benzodiazepines for agitation and seizures, active cooling for elevated body temperature.
Legal Status[edit]
25C-NBOMe is controlled in the most restrictive scheduling category in multiple major jurisdictions, driven by documented fatalities and emergency presentations associated with the NBOMe class.
| Jurisdiction | Classification | Key provisions |
|---|---|---|
| United States | Schedule I (Controlled Substances Act) | Temporarily placed November 15, 2013 alongside 25I-NBOMe and 25B-NBOMe;[5] extended 2015;[11] permanent scheduling followedcitation needed |
| United Kingdom | Class A (Misuse of Drugs Act 1971) | Temporary control June 2013; permanent Class A from June 2014[12] |
| Canada | Schedule III (Controlled Drugs and Substances Act) | Controlled from October 12, 2016[12] |
| Brazil | Controlled substance | Listed February 18, 2014[12] |
| Russia | Controlled substance | Listed October 2011[12] |
| Israel | Controlled substance | Listed May 2013[12] |
| Sweden | Controlled substance | Listed August 1, 2013 (unconfirmed)[12] |
| Australia | Status unconfirmed | Likely controlled under analog provisions or state-level drug laws; 25C-NBOMe circulates in Australian drug markets as of 2024citation needed |
Frequently asked questions
What is 25C-NBOMe?
25C-NBOMe is a synthetic phenethylamine psychedelic of the NBOMe class, derived from 2C-C, active at microgram doses sublingually. It acts as a potent 5-HT₂A agonist first synthesized by Ralf Heim in 2003; no controlled human study has been published.
How long does 25C-NBOMe last?
Total duration by route of administration — Sublingual: 8 – 10 hours. Ranges vary with dose and individual factors; see the duration table for onset, peak, and after-effect phases.
Where can I find dosage information for 25C-NBOMe?
Psychedex publishes a dosage table for 25C-NBOMe on this page covering these routes of administration: sublingual. Dose values are presented only in that table, always alongside their route of administration.
What are dangerous combinations with 25C-NBOMe?
The highest-severity documented interactions for 25C-NBOMe: MAOIs (Lethal), Buspirone (Dangerous), Dopamine agonists (Dangerous), GHB, Baclofen (Dangerous), GHB, GBL (Dangerous). See the interactions section for the full list with mechanisms and severity levels.
Is 25C-NBOMe addictive?
Psychedex records tolerance and dependence data rather than a yes/no rating. Recorded tolerance indicators for 25C-NBOMe: tolerance builds rapid; full reset takes 14 days; cross-tolerance develops with LSD, psilocybin, DMT, mescaline, 25I-NBOMe, 25B-NBOMe, DOI, 2C-B. See the article's dependence and safety sections for recorded dependence data.
experience reports
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First-person accounts of subjective effects, timing, and outcomes — submitted for harm reduction.
references
- [1]
- [2]
- [3]
- [4]
- [5] ^abcdDrug Enforcement Administration (2013) Schedules of controlled substances: temporary placement of three synthetic phenethylamines into Schedule I. Final order. — Federal Register PMID:24236337
- [6] ^abcLuethi D, Liechti ME (2020) Designer drugs: mechanism of action and adverse effects — Archives of Toxicology doi:10.1007/s00204-020-02693-7
references
- [1]
- [2]
- [3]
- [4]
- [5] ^abcdDrug Enforcement Administration (2013) Schedules of controlled substances: temporary placement of three synthetic phenethylamines into Schedule I. Final order. — Federal Register PMID:24236337
- [6] ^abcLuethi D, Liechti ME (2020) Designer drugs: mechanism of action and adverse effects — Archives of Toxicology doi:10.1007/s00204-020-02693-7