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Hyoscyamus niger Facts

Deliriant; Substituted tropane; Muscarinic acetylcholine receptor antagonist

Description

Black henbane (Hyoscyamus niger L., Solanaceae) is a toxic herbaceous plant whose preparations act as anticholinergic deliriants. Its dominant psychoactive alkaloids are scopolamine (hyoscine) and hyoscyamine, both of which block muscarinic acetylcholine receptors throughout the nervous system.[1] Scopolamine drives the central effects — sedation, amnesia, and delirium — by suppressing cholinergic signaling across the brain.[2]

Subjective effects include delirium, visual and auditory hallucinations, amnesia, and severe cognitive disorientation. The defining quality is anticholinergic delirium — a non-lucid, agitated state in which the person cannot distinguish hallucination from reality and has no awareness of being intoxicated.[3]

No dependence or withdrawal has been documented; the aversive nature of anticholinergic delirium strongly limits voluntary repeat use.[4] The margin between a psychoactive dose and a dangerous one is narrow and unpredictable — alkaloid content varies enormously across strains, plant parts, and growing conditions.[3]

Dose and duration

No dose or duration recorded for any route.

Body and dependence

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

Tolerance

Builds
Not recorded
Fully resets after
Not recorded
Carries over to
atropine; scopolamine (pharmaceutical); other muscarinic antagonists

Effectslikely at a common dose

Perception
Light sensitivity; Spatial disorientation; Visual acuity suppression; +12 possible, including Vestibular distortion, Visual haze / noise, Double vision
Body
Abnormal heartbeat; Constipation; Dry mouth; Motor control impairment; Pupil dilation; Temperature dysregulation; +19 possible, including Dehydration sensation, Dizziness, Heart rate perception changes
Thinking
Memory fragmentation; Analysis suppression; Cognitive impairment; Confusion; Decision impairment; Focus suppression; Information processing suppression; Memory suppression; Thought disorganization; +7 possible, including Cognitive dysphoria, Delusions of sobriety, Language suppression
Feeling
none likely · 5 possible, including Anxiety, Dysphoria, Emotional lability
Self
none likely · 7 possible, including Communication suppression, Social disconnection, Compulsive repetitive behavior
Time
Temporal disorientation; +1 possible

Who shouldn't take it

Absolute
Pregnancy; Pediatric exposure; Concurrent anticholinergic medications
Relative
Pre-existing cardiac conditions; Psychotic spectrum disorders; Hepatic impairment; Urinary retention / prostatic hypertrophy; Elderly individuals; Angle-closure glaucoma

Combinations60 recorded

Dangerous (18)
Amphetamines; Antihistamines; Antipsychotics; Atypical antipsychotics; Buprenorphine, Kratom; GHB, GBL; MDMA, MDA; Naltrexone; Opioids; Ephedrine, Pseudoephedrine; GHB, Baclofen; Ibogaine; Ketamine, DXM, PCP; Local anesthetics; NDRIs (Wellbutrin); Salvia, Ibogaine; SSRIs; Stimulants
Caution (35)
See full page: psychedex.org/substances/hyoscyamus-niger
Not graded (7)
Not listed never means safe.

Seek help immediately if

Deliriants are genuinely dangerous — treat any strong reaction as a medical emergency.

  • True delirium — confused, disoriented, doesn't know what's real or recognize people/danger
  • Vivid, frightening hallucinations; agitation or aggression
  • Hot, flushed, dry skin and high body temperature
  • Dilated pupils; blurred vision
  • Fast heartbeat; inability to urinate
  • Seizures; unconsciousness

What to do

  1. Call emergency services — deliriant poisoning (especially datura / belladonna) can be life-threatening
  2. Keep them physically safe — they may not know what they're doing and can badly injure themselves; remove hazards and stay with them
  3. Do not leave them alone; do not try to reason them out of it — they are delirious
  4. If overheating, cool the body
  5. Recovery position if drowsy, vomiting, or unconscious; be ready for rescue breaths / CPR

Deliriant effects are long (many hours to more than a day) and the person is not safe or in control throughout. The main dangers are self-injury during delirium, overheating, and — for potent anticholinergics like datura — cardiac and central-nervous-system toxicity. Medical monitoring is often needed.

988 Suicide & Crisis LifelineFireside Project: 62-FIRESIDE

Version r2 · Not medical advice

References

  1. [1]
    ^Shim KH, Kang MJ, Sharma N, An SSA (2022) Beauty of the beast: anticholinergic tropane alkaloids in therapeutics — Natural Products and Bioprospecting doi:10.1007/s13659-022-00357-w
  2. [2]
    ^Renner UD, Oertel R, Kirch W (2005) Pharmacokinetics and pharmacodynamics in clinical use of scopolamine — Therapeutic Drug Monitoring PMID:16175141
  3. [3]
    ^abAlizadeh A, Moshiri M, Alizadeh J, Balali-Mood M (2014) Black henbane and its toxicity - a descriptive review — Avicenna Journal of Phytomedicine PMID:25386392
  4. [4]
    ^Fatur K, Kreft S (2021) Nixing the nightshades: Traditional knowledge of intoxicating members of the Solanaceae among hallucinogenic plant and mushroom users in Slovenia — PLoS ONE doi:10.1371/journal.pone.0247688
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