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25C-NBOH Facts

Psychedelic; Substituted phenethylamine; Serotonin 2A receptor agonist

Description

25C-NBOH is a synthetic psychedelic of the phenethylamine class. It activates serotonin receptors in the brain, producing the visual and cognitive shifts characteristic of serotonergic psychedelics.[1][2]

Subjective effects include geometric visual patterns, color enhancement, emotional intensification, conceptual thinking, and a sense of boundary dissolution. The experience is more visually driven and physically stimulating than tryptamine psychedelics, with a narrow gap between threshold and strong effects — small dose changes produce large shifts in intensity.

25C-NBOH does not produce physical dependence, but animal studies document dangerous heart rhythm changes and heart cell death.[3] Active in microgram quantities with a steep dose-response curve, the compound shares a structural class with 25C-NBOMe, for which documented fatalities exist.[4][5]

Dose and durationby route · individual sensitivity varies

Sublingual(µg)
Threshold< 100 µgLight250 – 500 µgCommon500 – 750 µgStrong750 – 1000 µgHeavy1000+ µg

Starts in 15 – 45 minLasts 5 – 7 hoursAfter-effects 3 – 6 days

Body and dependence

Acute toxicity
Moderate
Chronic toxicity
Moderate
Physical dependence
None
Psychological dependence
Negligible
Withdrawal
None recorded
Compulsive redosing
Negligible

Tolerance

Builds
Rapid
Fully resets after
14 days
Carries over to
LSD; psilocybin; mescaline; 25C-NBOMe; 25I-NBOMe; 25I-NBOH; other NBOMe/NBOH compounds; serotonergic psychedelics

Effectslikely at a common dose

Perception
Color enhancement; Visual drifting; Color alteration; Tracers; Brightness alteration; Music enhancement; Symmetrical texture repetition; Environmental patterning; Geometry; Visual breathing; +25 possible, including Spatial disorientation, Visual haze / noise, Double vision
Body
Stimulation; Pupil dilation; Wakefulness; Body high; Body scan awareness; +29 possible, including Temperature dysregulation, Muscle tension, Vasoconstriction
Thinking
Pattern recognition enhancement; Conceptual thinking; Novelty enhancement; Immersion enhancement; Aesthetic enhancement; Openness enhancement; Thought connectivity; +23 possible, including Decision impairment, Memory suppression, Cognitive impairment
Feeling
Emotional enhancement; +8 possible, including Emotional lability, Anxiety, Paranoia
Self
none likely · 9 possible, including Derealization, Depersonalization
Time
Time alteration; +4 possible, including Temporal disorientation
Transpersonal
none likely · 1 possible
Awareness
none likely · 5 possible

Who shouldn't take it

Absolute
Concurrent QT-prolonging medications; Structural heart disease; Pre-existing cardiac arrhythmia; Congenital long QT syndrome; Seizure disorders / epilepsy; Pregnancy; MAO inhibitor therapy
Relative
Personal or family history of psychotic disorders; Hepatic impairment; SSRI/SNRI therapy

Combinations61 recorded

Lethal (1)
MAOIs
Dangerous (18)
MDMA, MDA; NRIs; Buspirone; Dopamine agonists; GHB, Baclofen; GHB, GBL; Ibogaine; Ketamine, DXM, PCP; Lithium; Local anesthetics; MDMA, Amphetamines; NDRIs (Wellbutrin); Psychedelics; Salvia, Ibogaine; SNRIs; SSRIs; Stimulants; Synthetic cannabinoids
Caution (37)
See full page: psychedex.org/substances/25c-nboh
Not graded (5)
Not listed never means safe.

Seek help immediately if

Most difficulty is psychological (intense fear, panic, confusion) and passes with calm support — the signs below mean seek emergency help:

  • Very high body temperature; hot, dry skin
  • Seizures
  • Chest pain; fast or irregular heartbeat
  • Severe muscle rigidity, tremor, or twitching (possible serotonin syndrome)
  • Cold, pale, or blue fingers/toes — severe vasoconstriction (notably NBOMe / DOx)
  • Persistent vomiting; unconsciousness; uncontrollable agitation or risk of self-harm

What to do

  1. Stay calm and reassure — remind them they took a drug and the effect will pass
  2. Move to a calm, quiet, safe space with low light; reduce noise and sensory input
  3. Keep them from harm — they may act on fear or confusion; stay with them, don't leave them alone
  4. Talk them down gently; don't grab or restrain unless they're in danger
  5. For the medical signs above (overheating, seizure, chest pain, vasoconstriction, unresponsive) call emergency services
  6. If overheating, cool the body; be ready to give rescue breaths / CPR

The experience is time-limited and usually resolves with calm reassurance in a safe setting — psychological first aid, not medication. Serious physical harm is uncommon for classic psychedelics (LSD, psilocybin) but real for some potent phenethylamines (NBOMe, DOx), where hyperthermia, seizures, and vasoconstriction warrant emergency care.

988 Suicide & Crisis LifelineFireside Project: 62-FIRESIDE

Version r1 · Not medical advice

References

  1. [1]
    ^Eshleman AJ, Wolfrum KM, Reed JF, Kim SO, Johnson RA, Janowsky A (2018) Neurochemical pharmacology of psychoactive substituted N-benzylphenethylamines: High potency agonists at 5-HT2A receptors. — Biochemical Pharmacology doi:10.1016/j.bcp.2018.09.024
  2. [2]
    ^Poulie CBM, Jensen AA, Halberstadt AL, Kristensen JL (2020) DARK Classics in Chemical Neuroscience: NBOMes — ACS Chemical Neuroscience doi:10.1021/acschemneuro.9b00528
  3. [3]
    ^Yoon KS, Cha HJ, Choi SO, Lee JM (2022) 2-((2-(4-Iodo-2,5-dimethoxyphenyl)ethylamino)methyl)phenol (25I-NBOH) and 2-(((2-(4-chloro-2,5-dimethoxyphenyl)ethyl)amino)methyl)phenol (25C-NBOH) induce adverse effects on the cardiovascular system — Toxicology Letters doi:10.1016/j.toxlet.2021.11.016
  4. [4]
    ^Andreasen MF, Telving R, Rosendal I, Eg MB, Hasselstrøm JB, Andersen LV (2015) A fatal poisoning involving 25C-NBOMe. — Forensic Science International doi:10.1016/j.forsciint.2015.03.012
  5. [5]
    ^Morini L, Bernini M, Vezzoli S, Restori M, Moretti M, Crenna S, Papa P, Locatelli C, Osculati AMM, Vignali C, Groppi A (2017) Death after 25C-NBOMe and 25H-NBOMe consumption. — Forensic Science International doi:10.1016/j.forsciint.2017.08.028
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