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25E-NBOH

4-ethyl-2,5-dimethoxy-N-(2-hydroxybenzyl)phenethylamine

Overview

25E-NBOH (2C-E-NBOH) is a synthetic psychedelic of the phenethylamine class. It is a close chemical relative of 2C-E, modified by the addition of an N-benzyl group that makes it active at far lower doses. It activates serotonin receptors in the brain,[1] producing the visual distortions and cognitive shifts characteristic of classical psychedelics.

25E-NBOH (2C-E-NBOH) is a synthetic psychedelic of the phenethylamine class. It is an N-benzyl derivative of 2C-E, distinguished from the related NBOMe series by a hydroxyl group on the benzyl ring. 25E-NBOH is a full agonist at serotonin 5-HT₂A receptors,[1] producing its effects by disrupting the brain's default filtering of sensory and cognitive input.

Entity
25E-NBOH
PSX-0021
25E-NBOH 2D chemical structure
Open Beta

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NoticeAll →
•1 lethal interaction(all →)
Substitutive name4-ethyl-2,5-dimethoxy-(N-(2-hydroxybenzyl))phenethylamine
Threshold
< 50 µg
Light
200 – 600 µg
Common
600 – 1000 µg
Strong
1000 – 1500 µg
Heavy
1500+ µg
12340 h2 h4 h5 h
1Onset
15m–45m2Come-up
30m–1h3Peak
1.5h–2.5h4Resolution
1h–2hAftereffects2h–5h
Total4h–6h
Builduprapid
Full reset14 days
Cross-tol.
LSD, psilocybin, mescaline +4 more
Absolute3 entries
Cardiovascular diseaseSeizure disordersMAOI use
Relative5 entries
Concurrent stimulant useSeizure-threshold-lowering agentsPsychotic disordersPregnancyLithium
Dosage varies by body weight, tolerance & metabolism · Not medical advice · Terms
See an error? Suggest correction
See an error? Suggest correction

The NBOH scaffold was developed around 2009–2010 by Martin Hansen to create brain-imaging agents for serotonin receptors.[2] When related NBOMe compounds were banned in the United States in 2013, the NBOH series entered recreational markets as a legal alternative. 25E-NBOH appeared around 2018–2019 and remains unscheduled under international treaties, though several countries have banned it individually.[3]

Subjective effects include geometric visual patterns, brightened colors, cognitive stimulation, analytical clarity, and heightened verbal fluency. The experience is unusually lucid — perception becomes dramatically altered while the capacity to think and speak stays largely intact, distinguishing it from the cognitive dissolution characteristic of high-dose tryptamines. Muscle tension, cold extremities, nausea, and a diffuse physical pressure from vasoconstriction are characteristic unwanted effects.

25E-NBOH does not produce physical dependence, but its toxic dose in humans is unknown, and at least one source references fatal cases.[4] The primary dangers are cardiovascular: blood vessel constriction can drive dangerous blood pressure elevation, and the class carries documented risk of seizures and fatal overheating.[5] The evidence base is thin — one animal study, metabolic profiling, and community reports.

History[edit]

Discovery

The parent 2C-E was first documented by Alexander Shulgin.[6] The NBOH modification was developed around 2009–2010 by Martin Hansen, who was building molecular tools for imaging serotonin receptors in living brain tissue.[2] 25CN-NBOH emerged as the most pharmacologically significant compound in that program;[7][8] 25E-NBOH received less individual study.

Market Emergence and Forensic Detection

When several NBOMe compounds were placed into Schedule I in the United States in 2013,[9] the NBOH series entered recreational markets as a legal alternative. 25E-NBOH appeared around 2018–2019,[3] first identified by Brazilian police from seized blotter papers.[10][11]

Analytical Challenges

25E-NBOH breaks down into 2C-E under the heat of standard gas chromatography.[12][10] This likely caused its presence to be underreported in seized materials. Liquid chromatography or NMR methods are needed for reliable identification.

Chemistry[edit]

Structural Class

25E-NBOH belongs to the N-benzylphenethylamine class — a family of potent serotonergic psychedelics built from 2C-x phenethylamines with an N-benzyl group attached. It is derived from 2C-E; attaching the N-(2-hydroxybenzyl) group dramatically increases binding at serotonin receptors compared to 2C-E alone.[5] It differs from 25E-NBOMe by a single functional group — a hydroxyl instead of a methoxy on the benzyl ring — creating a pharmacologically and legally distinct compound.[9]

Molecular Properties

Molecular formulaC₁₉H₂₅NO₃
Molecular weight315.4 g/mol

Physical Properties

A critical property is thermolability: 25E-NBOH breaks down into 2C-E under the heat of standard gas chromatography.[12][11][10] This is shared across the NBOH class and requires liquid chromatography or NMR for reliable identification.

Pharmacology[edit]

Mechanism of Action

25E-NBOH produces its effects by activating serotonin receptors in the brain.[1][5] It is a full agonist — binding tightly and triggering those receptors completely.[1] The exact cellular signaling route behind its psychedelic effects is still being worked out; the closely related compound 25CN-NBOH provides the closest structural reference for how this class works.[13][14][15]

A secondary mechanism drives the physical body load. The NBOH class also binds epinephrine receptors, causing blood vessels throughout the body to constrict.[16][17] This produces elevated blood pressure, tachycardia, cold extremities, and muscle tension.

Pharmacokinetics

No human pharmacokinetic data exist for 25E-NBOH. Studies in laboratory settings confirm that 2C-E is produced as a metabolite when the body breaks down 25E-NBOH.[3][4] The sublingual route partially bypasses liver breakdown — by analogy with closely related NBOH compounds, which show moderate susceptibility to liver metabolism.[18][9]

Neuroscience[edit]

Where It Acts

No direct brain imaging data exist for 25E-NBOH. Its neural effects are inferred from its confirmed activity at serotonin receptors.[1] Those receptors concentrate on neurons in the prefrontal cortex, where activation disrupts the brain's normal filtering of sensory information — producing enhanced perception, unusual associative thinking, and synesthesia-like phenomena.

Why It Matters

One influential framework proposes that psychedelics loosen the brain's top-down predictions, allowing raw sensory data to shape conscious experience more directly — consistent with the visual distortions and cognitive flexibility reported with 25E-NBOH. A related compound, 25C-NBF, has shown neuroplasticity-promoting and rapid antidepressant effects in rodents,[19] suggesting the broader N-benzylphenethylamine class may share the brain-rewiring capacity documented for classical psychedelics.

Subjective Effects[edit]

Summary

The 25E-NBOH experience is defined by a tension between mental clarity and physical discomfort. Visual perception becomes dramatically altered — geometry, brightened colors, rippling surfaces — while analytical thinking and verbal fluency remain largely intact. Muscle tension, physical pressure, and cold extremities accompany the experience, driven by the compound's blood vessel-constricting secondary mechanism.

Compared to 2C-E, which requires milligram quantities and lasts considerably longer, 25E-NBOH is active at microgram doses with a shorter timeline. It is more stimulating and visually oriented than psilocybin, but carries a cardiovascular body load closer to the NBOMe series than to classical tryptamine psychedelics.

The NBOH scaffold was developed around 2009–2010 by Martin Hansen as part of a program to create brain-imaging agents for serotonin receptors.[2] 25E-NBOH appeared on research chemical markets approximately 2018–2019,[3] following the scheduling of structurally related NBOMe compounds. It circulates primarily on blotter paper and remains unscheduled under international drug treaties, though several countries have banned it individually.

Subjective effects include geometric visual patterns, color enhancement, cognitive stimulation, and body load. The experience pairs unusual analytical clarity — verbal fluency and self-awareness remain relatively intact — with pronounced physical tension from vasoconstriction that distinguishes it from classical psychedelics. Muscle soreness, cold extremities, and nausea are characteristic unsought effects.

No physical dependence has been documented, and the toxic dose in humans is unknown — one source references fatal cases without clinical details.[4] The primary acute risks are cardiovascular: vasoconstriction from adrenoceptor activity can produce dangerous blood pressure elevation, compounded by seizure and overheating risk at the class level.[5] No clinical studies have been conducted; the current understanding rests on a single animal pharmacology study, metabolic profiling, and community reports.

History[edit]

Discovery

The parent compound 2C-E was first synthesized and documented by Alexander Shulgin in PiHKAL.[6] The NBOH (N-(2-hydroxybenzyl)) modification was developed around 2009–2010 by Martin Hansen and colleagues at the University of Copenhagen, who sought to create agonist PET radioligands for imaging serotonin 5-HT₂A receptors in living brain tissue.[2] 25CN-NBOH emerged as the program's most pharmacologically significant compound,[7][8] while 25E-NBOH and other members of the series received less individual characterization.

Market Emergence and Forensic Detection

After several NBOMe compounds were placed into Schedule I in the United States in 2013,[9] the structurally distinct NBOH series entered the research chemical market as an alternative. 25E-NBOH appeared around 2018–2019.[3] Its first forensic identification came from blotter papers seized by Brazilian police in 2017–2018, characterized using multiple spectroscopic techniques,[10] following a similar identification of 25I-NBOH in Brazil the previous year.[11]

Analytical Challenges

Early forensic identification was complicated by 25E-NBOH's thermolability — it breaks down into its parent compound 2C-E under the heat of standard gas chromatography.[12][10] This property likely caused underreporting of its presence in seized materials and necessitated liquid chromatography or NMR-based methods for definitive identification.

Chemistry[edit]

Structural Class

25E-NBOH belongs to the N-benzylphenethylamine class, a family of potent serotonergic psychedelics created by attaching an N-benzyl group to 2C-x phenethylamines. The structural lineage runs from mescaline through 2C-E (4-ethyl-2,5-dimethoxyphenethylamine) to 25E-NBOH, where an N-(2-hydroxybenzyl) group is added to the nitrogen. This N-benzyl addition dramatically increases binding affinity at 5-HT₂A receptors compared to the parent 2C-E.[5]

The compound differs from its NBOMe counterpart (25E-NBOMe) by a single functional group: a free hydroxyl on the benzyl ring rather than a methoxy group. This change retains potent 5-HT₂A activity while creating a pharmacologically and legally distinct compound.[9]

Molecular Properties

Molecular formulaC₁₉H₂₅NO₃
Molecular weight315.4 g/mol

The molecule combines a 2,5-dimethoxy-4-ethylphenethylamine backbone (the 2C-E scaffold) linked through a secondary amine to a 2-hydroxybenzyl group. Key features include two aromatic methoxy groups, an ethyl substituent at the 4-position, and a phenolic hydroxyl on the N-benzyl ring. The compound contains no chirality centers.

Physical Properties

No published data exist for melting point, solubility, or stability of 25E-NBOH. It is distributed on blotter paper for sublingual use, implying adequate stability in dry solid form at room temperature.

A critical property is thermolability: 25E-NBOH degrades to 2C-E under the heat of standard gas chromatography (inlet temperatures of 250–300°C).[12][11][10] The thermal breakdown pathway cleaves the N-benzyl bond, regenerating the parent 2C-E molecule. This property is shared across the NBOH class and requires liquid chromatography or NMR for reliable identification.

Pharmacology[edit]

Mechanism of Action

25E-NBOH produces psychedelic effects primarily through agonism at serotonin 5-HT₂A receptors.[1][5] It has been confirmed as a high-affinity full agonist at both 5-HT₂A and 5-HT₂C receptors,[1] though no specific binding affinity values have been published for this compound.

Recent structural work has shown that the hallucinogenic effects of 5-HT₂A agonists depend on non-canonical Gᵢ signalling rather than the Gq pathway.[13] Whether 25E-NBOH shows preference between these signalling pathways has not been investigated. Studies on the closely related 25CN-NBOH provide a structural framework for understanding how N-benzylphenethylamines balance different downstream signalling routes.[14][15]

Secondary effects likely include binding at alpha-1A adrenoceptors, documented for the NBOMe class at meaningful potency.[16][17] This receptor target is responsible for the vasoconstriction and cardiovascular stimulation that characterize the phenethylamine body load.

Pharmacokinetics

No human pharmacokinetic data exist for 25E-NBOH. Bioavailability, time to peak effect, plasma half-life, and elimination pathways have not been measured in any species.

Metabolic profiling has been conducted in laboratory settings. Vágnerová et al. mapped the metabolic pathway of 25E-NBOH in human liver preparations and animal models, confirming that 2C-E (the parent phenethylamine) is produced as a metabolite through cleavage of the N-benzyl group.[3] Xiang et al. independently identified additional metabolites using high-resolution mass spectrometry.[4]

The sublingual route — standard for blotter paper delivery — partially bypasses liver metabolism, which may explain the compound's activity at very low doses despite expected metabolic vulnerability. By analogy with the closely related 25CN-NBOH, NBOH compounds show moderate susceptibility to liver metabolism.[18][9]

Neuroscience[edit]

Where It Acts

No direct brain imaging or electrophysiology data exist for 25E-NBOH. Its neural effects are inferred from its confirmed serotonin 2A receptor agonist pharmacology.[1] 5-HT₂A receptors concentrate on pyramidal neurons in the prefrontal cortex, where their activation triggers glutamate release and disrupts the brain's normal hierarchical processing of sensory information.

At the network level, serotonergic psychedelics reduce connectivity within the default mode network (associated with ego dissolution), impair thalamic filtering of sensory input (producing enhanced perception), and increase communication between brain regions that do not normally interact (underlying unusual associative thinking and synesthesia-like phenomena).

Why It Matters

The REBUS model proposes that psychedelics loosen the brain's top-down predictions, allowing raw sensory data greater influence on conscious experience — consistent with the visual distortions and conceptual flexibility reported with 25E-NBOH. The related compound 25C-NBF has demonstrated psychoplastogenic properties (promoting neural growth) and rapid antidepressant effects in rodents,[19] suggesting the N-benzylphenethylamine class may share the neuroplasticity-promoting capacity documented for classical psychedelics.

Subjective Effects[edit]

Summary

The 25E-NBOH experience is defined by a distinctive tension between mental lucidity and physical discomfort. Users consistently report that analytical capacity and verbal fluency remain relatively intact even as visual perception becomes profoundly altered — a clear-headed quality that separates it from the cognitive dissolution characteristic of high-dose tryptamines. The experience intensifies proportionally with dose, progressing from mild visual enhancement at threshold to pronounced pattern recognition and transpersonal phenomena at higher levels. Set and setting strongly modulate the psychological character, but the somatic dimension — muscle tightness, cold extremities, a bodily pressure from vasoconstriction — is pharmacologically intrinsic and present across the dose range.

Compared to 2C-E, which requires milligram oral doses and lasts considerably longer, 25E-NBOH is active at microgram sublingual doses with a more compressed timeline. It is more stimulating and visually oriented than psilocybin, but carries a cardiovascular body load more reminiscent of the NBOMe series than of classical tryptamine psychedelics.

Effect Grid

Dose Level:
Description

Full psychedelic visual field emerges — visual drifting and morphing are prominent, geometric overlays appear on surfaces, color enhancement is vivid, and tracers follow moving objects. Internal hallucinations become accessible with closed eyes. Time alteration is pronounced; minutes may feel stretched or compressed unpredictably.

Cognitive effects include enhanced thought connectivity, pattern recognition enhancement, creativity enhancement, and introspective depth. The characteristic clear-headedness of 25E-NBOH is maintained — analytical capacity persists alongside perceptual disruption, distinguishing this from tryptamine psychedelics at equivalent intensity.

Vasoconstriction is notable at this tier — muscle soreness, cold extremities, and bodily pressure are commonly reported. Stimulation is pronounced. Temperature dysregulation may occur. Total duration is 4–6 hours.

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

Perception(47)likelihood · intensity
Color alteration
likely
Geometry
likely
Color enhancement
likely
Visual drifting
likely
Visual breathing
likely
Tracers
possible
Music enhancement
possible
Brightness alteration
possible
Double vision!
rare

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

Environmental patterning · Symmetrical texture repetition · After-images · Auditory distortion · Auditory enhancement · Depth perception distortion · Light sensitivity · Perspective distortion · Sound sensitivity · Visual morphing · Touch enhancement · Visual acuity enhancement · Auditory misinterpretation · Peripheral vision distortion · Spatial disorientation · Visual diffraction · Visual haze / noise · Visual melting · Synesthesia · Peripheral misidentification · Proprioceptive distortion · Vestibular distortion · Olfactory enhancement · Taste enhancement · Visual processing acceleration · Visual magnification · Flashbacks · Object transformations · Internal hallucinations · Object activation · Visual recursion · Environmental orbism / cubism · External hallucinations · Visual scenery slicing · Auditory hallucinations · Perspective hallucinations · Visual flipping · Persisting hallucinations

Body(43)likelihood · intensity
Pupil dilation
likely
Body scan awareness
likely
Stimulation
possible
Spontaneous body sensations
possible
Body high
possible
Vasoconstriction!
possible
Muscle tension
possible
Temperature dysregulation!
possible
Motor control impairment!
possible

Spontaneous body sensations · Body high · Muscle tension · Wakefulness · Appetite suppression · Dry mouth · Tingling / electric sensations · Excessive sweating · Nausea · Dizziness · Headache · Heart rate perception changes · Insomnia · Laughter fits · Motor control impairment · Physical fatigue · Restlessness · Tactile euphoria · Vibrations / buzzing · Bruxism · Sexual arousal enhancement · Dehydration sensation · Bodily lightness · Bodily pressures · Body schema distortion · Breathing alteration · Salivation · Trembling · Abnormal heartbeat · Increased urination · Diarrhea · Involuntary body movements · Nystagmus (eye wobbles) · Vomiting · Motor control enhancement · Seizure threshold reduction · Bodily dissociation · Tactile hallucination

Wakefulness · Appetite suppression · Dry mouth · Tingling / electric sensations · Excessive sweating · Nausea · Dizziness · Headache · Heart rate perception changes · Insomnia · Laughter fits · Physical fatigue · Restlessness · Tactile euphoria · Vibrations / buzzing · Bruxism · Sexual arousal enhancement · Dehydration sensation · Bodily lightness · Bodily pressures · Body schema distortion · Breathing alteration · Salivation · Trembling · Abnormal heartbeat · Increased urination · Diarrhea · Involuntary body movements · Nystagmus (eye wobbles) · Vomiting · Motor control enhancement · Seizure threshold reduction · Bodily dissociation · Tactile hallucination

Thinking(39)likelihood · intensity
Pattern recognition enhancement
possible
Novelty enhancement
possible
Aesthetic enhancement
possible
Conceptual thinking
possible
Memory suppression
possible
Thought connectivity
possible
Decision impairment!
possible
Suggestibility enhancement!
possible
Delusions of sobriety!
rare

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

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

Feeling(11)likelihood · intensity
Emotional enhancement
possible
Emotional lability
possible
Euphoria
possible
Simultaneous emotions
possible
Anxiety
possible
Empathy enhancement
possible
Catharsis
possible
Paranoia!
possible
Depression!
rare

Simultaneous emotions · Anxiety · Empathy enhancement · Catharsis · Dysphoria · Irritability

Dysphoria · Irritability

Self(20)likelihood · intensity
Derealization
possible
Emotional susceptibility
possible
Depersonalization
possible
Disinhibition
possible
Social connection
possible
Automaticity
possible
Trust enhancement
possible
Compulsive repetitive behavior!
rare
Self-control suppression!
rare

Disinhibition · Social connection · Automaticity · Trust enhancement · Communication enhancement · Flow state · Sociability enhancement · Communication suppression · Sociability suppression · Social disconnection · Boundary dissolution · Cognitive disconnection · Ego dissolution · Identity alteration · Telepathic feelings

Communication enhancement · Flow state · Sociability enhancement · Communication suppression · Sociability suppression · Social disconnection · Boundary dissolution · Cognitive disconnection · Ego dissolution · Identity alteration · Telepathic feelings

Time(6)likelihood · intensity
Time alteration
likely
Present-moment absorption
possible
Temporal disorientation
possible
Deja vu
possible
Jamais vu
possible
Time cessation
v.rare

Time cessation

Transpersonal(8)likelihood · intensity
Unity and interconnectedness
possible
Existential realization
rare
Transpersonal feelings
v.rare
Noetic insight
v.rare
Non-dual awareness
v.rare
Transpersonal memory access
v.rare
Transpersonal visions
v.rare
Entity contact
v.rare

Transpersonal memory access · Transpersonal visions · Entity contact

Awareness(7)likelihood · intensity
Personal insight
possible
Cognitive dissonance
possible
Lucidity enhancement
possible
Mindfulness enhancement
possible
Anticipatory response
possible
Reality testing impairment!
rare
Recursive awareness
rare

Anticipatory response · Recursive awareness

report missing effect
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
Moderate
Chronic toxicity
Low
Withdrawal
None
Tolerance buildup
rapid
Tolerance reset
14 days
Dependence
Physical
None
Psychological
Negligible
Compulsive redosing
Negligible
Dose escalation
Negligible
Cross-tol.
LSD · psilo · mesc
Risk Shape
TOXPHYPSYWDRREDTOL

Toxicity

No controlled toxicity data, lethal dose values, or safety margins exist for 25E-NBOH in any species.

One published source states that 25E-NBOH has caused fatal poisoning cases,[4] but provides no case numbers or clinical details. This is the only reference to fatalities from this specific compound. safety citation needed

Class-Level Risks

The NBOMe/NBOH class carries a characteristic toxicity pattern from overstimulation of the body's stress response system and excess serotonin activity. A review of 51 published cases identified these complications[5]:

  • Seizures — documented across multiple compounds in the class
  • Dangerous body temperature elevation — can trigger muscle breakdown and organ failure
  • Muscle breakdown — linked to seizures, overheating, and sustained vasoconstriction
  • Agitation and delirium — including violent behavior and complete disorientation
  • Multi-organ failure — the terminal pathway in severe cases

NBOMe use has caused deaths.[17] Severe toxicity from blotter paper substances in this class has been documented clinically.[20]

Cardiovascular Effects

Adrenaline receptor binding — documented for the NBOMe class[16] — constricts blood vessels throughout the body. This produces high blood pressure, rapid heart rate, and reduced blood flow to the extremities. The serotonin component adds further cardiovascular risk through coronary vessel constriction.[21]

Analytical Misidentification

25E-NBOH breaks down into 2C-E under standard laboratory testing conditions,[12][10] and 2C-E is also produced as a metabolite in the body.[3] A positive test for 2C-E cannot distinguish between 2C-E use and 25E-NBOH use — poisoning cases from 25E-NBOH may be misattributed to 2C-E.

Psychological Risks

No controlled data on psychological adverse events exist for 25E-NBOH. By class analogy with serotonergic psychedelics:

Tolerance and Dependence

Tolerance

Rapid tolerance develops through downregulation — detectable within 24 hours of a single dose.[22] Repeated dosing over several days produces progressively diminished effects. Cross-tolerance exists between serotonergic psychedelics — 25E-NBOH use reduces the effects of LSD, psilocybin, mescaline, and other serotonin-acting psychedelics.

Dependence

No dependence studies have been conducted for 25E-NBOH.[1] Classical psychedelics show very low reinforcing potential in animal models — the related compound 25C-NBF produced no rewarding effects in rodents.[19] No evidence of compulsive use, physical dependence, or withdrawal exists for any NBOH compound.

1LETHAL
18DANGEROUS
37CAUTION
5UNGRADED
61 rules0 SOURCE-VERIFIED2 EDITOR-REVIEWED

MAOIs

MAOIs block the breakdown of serotonin in the body. Combining them with 25E-NBOH floods serotonin systems, risking a dangerous overloading response — overheating, seizures, and potentially death.[23] No safe combination protocol exists.

SSRIs and SNRIs

Chronic SSRI or SNRI use may blunt the effects of 25E-NBOH by reducing available serotonin receptors. The combined serotonergic state is complex and incompletely understood.[23]

Lithium

Lithium combined with serotonergic psychedelics has been associated with increased seizure risk in case reports. safety citation needed

Vasoconstrictive Substances

Combining 25E-NBOH with other substances that constrict blood vessels — amphetamines, cocaine, MDMA, ergotamines — adds to cardiovascular risk.[5] The combined effect can produce dangerous blood pressure elevation and severely reduced blood flow to extremities.

Seizure-Threshold-Lowering Agents

The class carries documented seizure risk. Combining with substances that independently lower seizure threshold — such as tramadol or bupropion — represents additive risk. safety citation needed

Contraindications

8 known
3ABSOLUTE
5RELATIVE

Absolute

  • Concurrent MAOI use: serotonin syndrome risk is mechanistically certain and potentially fatal
  • Seizure disorders: seizure threshold reduction is documented at class level[5][17]
  • Cardiovascular disease: pre-existing high blood pressure, coronary artery disease, peripheral vascular disease, or structural heart defects — blood vessel constriction from adrenaline receptor activity poses direct risk[16]

Relative

  • Personal or family history of psychotic disorders: serotonin receptor activation can trigger acute psychosis in predisposed individuals
  • Concurrent lithium use: seizure risk elevation reported at class level
  • Pregnancy: no reproductive safety data exist; effects of serotonin receptor activation during fetal development are unknown citation needed
  • Concurrent stimulant use: additive cardiovascular risk from combined blood vessel constriction

Harm Reduction[edit]

Forms & Identification

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

25E-NBOH circulates on blotter paper that is visually indistinguishable from LSD, NBOMe compounds, and other substances active at microgram doses. No visual inspection can confirm identity or dose.

Reagent testing provides preliminary identification but cannot confirm purity or dose. The compound's thermolability can confuse heat-based analytical methods. Quantitative laboratory analysis is the only reliable way to confirm both identity and dose.

Guidelines

  • Test every batch with reagent kits before use; consider laboratory analysis for quantitative confirmation
  • Start with the lowest available dose — 25E-NBOH is highly dose-sensitive, and small differences in amount can produce substantially different experiences
  • Use the sublingual route as intended; do not alter the route of administration
  • Have a sober, trusted companion present throughout the experience
  • Ensure access to a warm, comfortable environment — vasoconstriction can cause cold extremities and physical discomfort
  • Keep a light meal available for after the experience; avoid eating heavily beforehand
  • Allow a full recovery day afterward with no obligations
  • Wait at least two weeks between uses to allow full tolerance reset

Set & Setting

The clear-headed quality of 25E-NBOH does not reduce psychological risk. Cognitive lucidity can coexist with intense perceptual distortion and emotional intensity. A calm, familiar environment with a trusted sober companion provides the strongest foundation for a manageable experience.

The pronounced body load — muscle tension, cold extremities, physical pressure — is pharmacologically intrinsic. It is not a sign that something has gone wrong. Knowing this in advance reduces the likelihood of anxiety escalating in response to physical discomfort.

Aftercare & integration. Vasoconstriction-related body load may leave residual muscle soreness for 12–24 hours. Gentle movement, hydration, and warmth help with physical recovery. Adequate sleep the following night is important — the stimulating quality of the compound may make falling asleep difficult on the day of use.

Psychedelic experiences can surface unexpected emotional material. Journaling, conversation with a trusted person, or professional integration support can help process the experience. If distressing perceptual changes — visual haze / noise, trailing, pattern recognition in blank surfaces — persist beyond a few days, consult a healthcare provider familiar with HPPD.

Recovery & Support

25E-NBOH does not produce physical dependence, but patterns of frequent psychedelic use can become psychologically habitual. If use is escalating in frequency, occurring in response to emotional distress rather than intentional exploration, or causing conflict in daily life, professional support is appropriate.

Resources include psychedelic-informed therapists, harm reduction services such as DanceSafe and The Loop, and general substance use support through SAMHSA's National Helpline (1-800-662-4357).

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

Emergency Response

Recognizing an emergency: Uncomfortable physical effects — muscle tension, nausea, mild anxiety — are common and do not alone constitute an emergency. Seek immediate help if any of the following occur: seizure activity, loss of consciousness, chest pain, extreme body temperature (skin very hot to the touch), severe confusion or violent agitation, or sustained panic that cannot be talked through.

Immediate steps:

  • 1. Call emergency services immediately if seizure, unconsciousness, chest pain, or dangerous body temperature is present
  • 2. Keep the person in a cool, quiet environment
  • 3. If conscious, encourage slow breathing and provide calm reassurance
  • 4. If unconscious and breathing, place in the recovery position (on their side)
  • 5. Do not restrain the person unless they are in immediate danger of harming themselves
  • 6. Do not induce vomiting

What to tell the dispatcher: Name the substance (25E-NBOH or "a synthetic psychedelic from the NBOH class"), the approximate time of ingestion, the dose if known, and current symptoms. Good Samaritan laws in many jurisdictions protect people who call for help during a drug emergency.

No reversal agent exists for 25E-NBOH or any serotonergic psychedelic. Treatment is supportive.

Safety[edit]

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

Toxicity

No controlled toxicity data, lethal dose values, or safety margin calculations exist for 25E-NBOH in any species.

Xiang et al. state that 25E-NBOH "has caused several poisoning cases and even fatal cases",[4] but provide no case numbers, circumstances, or clinical details. This is the only published reference to fatalities from this specific compound. safety citation needed

Class-Level Risks

The NBOMe/NBOH class shares a toxicity pattern characterized by overstimulation of the sympathetic nervous system and excess serotonin activity. A review of 51 published NBOMe toxicity cases identified the following complications[5]:

  • Seizures — documented across multiple compounds in the class
  • Dangerous body temperature elevation — can trigger muscle breakdown and organ failure
  • Muscle breakdown — linked to seizures, overheating, and sustained vasoconstriction
  • Agitation and delirium — including violent behavior and complete disorientation
  • Multi-organ failure — the terminal pathway in severe cases

Zawilska et al. confirm this profile and report that NBOMe use has caused deaths.[17] Isbister et al. describe severe toxicity from blotter paper substances in this class.[20]

Cardiovascular Effects

Alpha-1A adrenoceptor binding documented for the NBOMe class[16] produces constriction of blood vessels throughout the body. This can cause high blood pressure, rapid heart rate, and reduced blood flow to the extremities. The serotonergic component adds further cardiovascular risk through coronary vessel constriction.[21]

Analytical Misidentification

25E-NBOH breaks down into 2C-E under standard laboratory testing conditions,[12][10] and 2C-E is also produced as an actual metabolite in the body.[3] This means laboratory detection of 2C-E in a person's system cannot distinguish between 2C-E use and 25E-NBOH use — cases of 25E-NBOH poisoning may be misattributed to 2C-E.

Psychological Risks

No controlled data on psychological adverse events exist for 25E-NBOH. By class analogy with serotonergic psychedelics:

Tolerance and Dependence

No published tolerance or dependence data exist for 25E-NBOH specifically.

Tolerance

By class pharmacology, rapid tolerance develops through downregulation after a single dose. Research in mice demonstrated that[22]:

  • Tolerance is detectable within 24 hours of a single administration
  • Repeated dosing over several days produces progressively diminished effects
  • Cross-tolerance exists between psychedelic 5-HT₂A agonists — using 25E-NBOH would be expected to reduce the effects of LSD, psilocybin, mescaline, and other serotonergic psychedelics, and vice versa

Dependence

No dependence studies have been conducted for 25E-NBOH.[1] Classical psychedelics as a class show very low reinforcing potential in animal models. The related compound 25C-NBF produced no rewarding or reinforcement in rodents.[19] No evidence of compulsive use, physical dependence, or withdrawal exists for any NBOH compound.

1LETHAL
18DANGEROUS
37CAUTION
5UNGRADED
61 rules0 SOURCE-VERIFIED2 EDITOR-REVIEWED

MAOIs

Combination with monoamine oxidase inhibitors — both reversible (moclobemide) and irreversible (phenelzine, tranylcypromine) — carries serious serotonin syndrome risk. The combination of 5-HT₂A agonism with elevated serotonin levels from monoamine oxidase inhibition can produce potentially fatal toxicity.[23] No safe combination protocol exists.

SSRIs and SNRIs

Chronic SSRI or SNRI use may blunt psychedelic effects through 5-HT₂A receptor downregulation. The interaction in combined serotonergic states is complex and incompletely understood.[23]

Lithium

Lithium combined with psychedelic 5-HT₂A agonists has been associated with increased seizure risk in case reports. safety citation needed

Vasoconstrictive Substances

Combining 25E-NBOH with other substances that constrict blood vessels (amphetamines, cocaine, MDMA, ergotamines) produces additive cardiovascular risk.[5] The combined effect can produce dangerous blood pressure elevation and reduced blood flow to extremities.

Seizure-Threshold-Lowering Agents

Given the seizure risk documented for the NBOMe/NBOH class, combination with substances that independently lower seizure threshold (tramadol, bupropion) represents additive risk. safety citation needed

Contraindications

8 known
3ABSOLUTE
5RELATIVE

Absolute

  • Concurrent MAOI use: serotonin syndrome risk is mechanistically certain and potentially fatal
  • Seizure disorders: seizure threshold reduction is documented at class level[5][17]
  • Cardiovascular disease: pre-existing high blood pressure, coronary artery disease, peripheral vascular disease, or structural heart defects — blood vessel constriction from adrenoceptor activity poses direct risk[16]

Relative

  • Personal or family history of psychotic disorders: 5-HT₂A agonism can trigger acute psychosis in predisposed individuals
  • Concurrent lithium use: seizure risk elevation reported at class level
  • Pregnancy: no reproductive safety data exist; effects of 5-HT₂A agonism during fetal development are unknown citation needed
  • Concurrent stimulant use: additive cardiovascular risk from combined blood vessel constriction

Harm Reduction[edit]

Forms & Identification

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

25E-NBOH circulates on blotter paper that is visually indistinguishable from blotters containing LSD, NBOMe compounds, or other substances active at microgram doses. No visual inspection can confirm identity or dosage.

Reagent testing provides preliminary identification but cannot confirm purity or dose. The compound's thermolability means it degrades to 2C-E under heat, which can confuse results from analytical methods that apply thermal energy. Quantitative laboratory analysis is the only way to confirm both identity and dose with certainty.

Guidelines

  • Test every batch with reagent kits before use; consider laboratory analysis services for quantitative confirmation
  • Start with the lowest available dose — 25E-NBOH is highly dose-sensitive, and small differences in amount can produce substantially different experiences
  • Use the sublingual route as intended; do not alter the route of administration
  • Have a sober, trusted companion present throughout the experience
  • Ensure access to a warm, comfortable environment — vasoconstriction can cause cold extremities and physical discomfort
  • Keep a light meal available for after the experience; avoid eating heavily beforehand
  • Allow a full recovery day afterward with no obligations
  • Wait at least two weeks between uses to allow full tolerance reset

Set & Setting

The clear-headed quality reported for 25E-NBOH does not reduce psychological risk — cognitive lucidity can coexist with intense perceptual distortion and emotional intensity. A calm, familiar environment with a trusted sober companion provides the strongest foundation for a manageable experience.

The pronounced body load (muscle tension, cold extremities, physical pressure) is pharmacologically intrinsic and not a sign that something has gone wrong. Knowing this in advance reduces the likelihood of anxiety spiraling in response to somatic discomfort.

Aftercare & integration. The vasoconstriction-related body load may leave residual muscle soreness for 12–24 hours after the experience. Gentle movement, hydration, and warmth help with physical recovery. Adequate sleep the following night is important — the stimulating quality of the compound may make falling asleep difficult on the day of use.

Psychedelic experiences can surface unexpected emotional material. Journaling, conversation with a trusted person, or professional integration support can help process the experience. If distressing perceptual changes (visual haze / noise, trailing, pattern recognition in blank surfaces) persist beyond a few days, consult a healthcare provider familiar with HPPD.

Recovery & Support

While 25E-NBOH does not produce physical dependence, patterns of frequent psychedelic use can become psychologically habitual. If use is escalating in frequency, occurring in response to emotional distress rather than intentional exploration, or causing conflict in daily life, professional support is appropriate.

Resources include psychedelic-informed therapists, harm reduction services such as DanceSafe and The Loop, and general substance use support through SAMHSA's National Helpline (1-800-662-4357).

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

Emergency Response

Recognizing an emergency: Uncomfortable physical effects (muscle tension, nausea, mild anxiety) are common and do not alone constitute an emergency. Seek immediate help if any of the following occur: seizure activity, loss of consciousness, chest pain, extreme body temperature (skin very hot to the touch), severe confusion or violent agitation, or sustained panic that the person cannot be talked through.

Immediate steps:

  • 1. Call emergency services immediately if seizure, unconsciousness, chest pain, or dangerous body temperature is present
  • 2. Keep the person in a cool, quiet environment
  • 3. If conscious, encourage slow breathing and provide calm reassurance
  • 4. If unconscious and breathing, place in the recovery position (on their side)
  • 5. Do not restrain the person unless they are in immediate danger of harming themselves
  • 6. Do not induce vomiting

What to tell the dispatcher: Name the substance (25E-NBOH or "a synthetic psychedelic from the NBOH class"), the approximate time of ingestion, the dose if known, and current symptoms. Good Samaritan laws in many jurisdictions protect people who call for help during a drug emergency.

No reversal agent exists for 25E-NBOH or any serotonergic psychedelic. Treatment is supportive.

Frequently asked questions

What is 25E-NBOH?

25E-NBOH is a synthetic phenethylamine psychedelic of the NBOH class, active at sublingual microgram doses. It acts as a full agonist at serotonin 5-HT₂A and 5-HT₂C receptors, developed circa 2010 as a PET radioligand precursor.

How long does 25E-NBOH last?

Total duration by route of administration — Sublingual: 4 – 6 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 25E-NBOH?

Psychedex publishes a dosage table for 25E-NBOH on this page covering these routes of administration: sublingual, insufflated. Dose values are presented only in that table, always alongside their route of administration.

What are dangerous combinations with 25E-NBOH?

The highest-severity documented interactions for 25E-NBOH: 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 25E-NBOH addictive?

Psychedex records tolerance and dependence data rather than a yes/no rating. Recorded tolerance indicators for 25E-NBOH: tolerance builds rapid; full reset takes 14 days; cross-tolerance develops with LSD, psilocybin, mescaline, DMT, DOx series, 25x-NBOMe compounds, 25x-NBOH compounds. See the article's dependence and safety sections for recorded dependence data.

experience reports

No experience reports yet. Be the first to contribute.

First-person accounts of subjective effects, timing, and outcomes — submitted for harm reduction.

references

  1. [1] 
    ^abcdeMunir DD, Shetty RA, Gatch MB, Sumien N, Hill RD, Priddy JA, Forster MJ (2025) Locomotor and discriminative stimulus effects of NBOH hallucinogens in rodents — Behavioural Pharmacology doi:10.1097/fbp.0000000000000802
  2. [2] 
    ^abEttrup A, Hansen M, Santini MA, Paine J, Gillings N, Palner M, Lehel S, Herth MM, Madsen J, Kristensen J, Begtrup M, Knudsen GM (2011) Radiosynthesis and in vivo evaluation of a series of substituted 11C-phenethylamines as 5-HT2A agonist PET tracers — European Journal of Nuclear Medicine and Molecular Imaging doi:10.1007/s00259-010-1686-8
  3. [3] 
    ^abcdVágnerová M, Palivec P, Mrnává M et al. (2026) Metabolic profile of 25E-NBOH in human liver microsomes, rat urine, and fungus Cunninghamella elegans — Journal of Pharmaceutical and Biomedical Analysis doi:10.1016/j.jpba.2026.117417
  4. [4] 
    ^abcXiang J, Wen D, Zhai W, Zhao J, Xiang P, Ma C, Shi Y (2024) Metabolic characterization of 25X-NBOH and 25X-NBOMe phenethylamines based on UHPLC-Q-Exactive Orbitrap MS in human liver microsomes. — Journal of Pharmaceutical and Biomedical Analysis doi:10.1016/j.jpba.2024.116020
  5. [5] 
    ^abcdefgHalberstadt AL (2017) Pharmacology and Toxicology of N-Benzylphenethylamine (NBOMe) Hallucinogens — Current Topics in Behavioral Neurosciences doi:10.1007/7854_2016_64
  6. [6] 
    ^Shulgin (1991) PiHKAL: A Chemical Love Story

references

  1. [1] 
    ^abcdeMunir DD, Shetty RA, Gatch MB, Sumien N, Hill RD, Priddy JA, Forster MJ (2025) Locomotor and discriminative stimulus effects of NBOH hallucinogens in rodents — Behavioural Pharmacology doi:10.1097/fbp.0000000000000802
  2. [2] 
    ^abEttrup A, Hansen M, Santini MA, Paine J, Gillings N, Palner M, Lehel S, Herth MM, Madsen J, Kristensen J, Begtrup M, Knudsen GM (2011) Radiosynthesis and in vivo evaluation of a series of substituted 11C-phenethylamines as 5-HT2A agonist PET tracers — European Journal of Nuclear Medicine and Molecular Imaging doi:10.1007/s00259-010-1686-8
  3. [3] 
    ^abcdVágnerová M, Palivec P, Mrnává M et al. (2026) Metabolic profile of 25E-NBOH in human liver microsomes, rat urine, and fungus Cunninghamella elegans — Journal of Pharmaceutical and Biomedical Analysis doi:10.1016/j.jpba.2026.117417
  4. [4] 
    ^abcXiang J, Wen D, Zhai W, Zhao J, Xiang P, Ma C, Shi Y (2024) Metabolic characterization of 25X-NBOH and 25X-NBOMe phenethylamines based on UHPLC-Q-Exactive Orbitrap MS in human liver microsomes. — Journal of Pharmaceutical and Biomedical Analysis doi:10.1016/j.jpba.2024.116020
  5. [5] 
    ^abcdefgHalberstadt AL (2017) Pharmacology and Toxicology of N-Benzylphenethylamine (NBOMe) Hallucinogens — Current Topics in Behavioral Neurosciences doi:10.1007/7854_2016_64
  6. [6] 
    ^Shulgin (1991) PiHKAL: A Chemical Love Story
Last updated Jun 4, 2026