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Clonazepam Facts

Depressant; Anxiolytic; Benzodiazepine; GABA-A receptor positive allosteric modulator

Description

Clonazepam is a synthetic depressant of the benzodiazepine class. It amplifies GABA — the brain's main calming signal — making neurons less excitable and producing its characteristic sedation and anxiety relief.[1][2]

Subjective effects include anxiety suppression, muscle relaxation, sedation, cognitive slowing, and behavioral disinhibition. The experience is defined by a disconnect between how sober the user feels and how impaired they are — anxiety dissolves and the mind quiets while judgment, memory, and coordination deteriorate unnoticed.[3]

Clonazepam produces physical dependence with regular use; stopping abruptly can trigger life-threatening seizures,[4] though acute toxicity from the drug alone is low. Opioid co-use raises one-year mortality by 78%,[5] and long-term use is a risk factor for cognitive decline in older adults.[6]

Dose and durationby route · individual sensitivity varies

Oral(mg)
Threshold< 0.125 mgLight0.25 – 0.5 mgCommon0.5 – 1.5 mgStrong1.5 – 3 mgHeavy3+ mg

Starts in 20 – 60 minLasts 8 – 12 hoursAfter-effects 8 – 48 hours

Body and dependence

Acute toxicity
Low
Chronic toxicity
Moderate
Physical dependence
High
Psychological dependence
High
Withdrawal
Life-threatening · fatal · medical supervision
Compulsive redosing
Moderate

Tolerance

Builds
Rapid
Fully resets after
Not recorded
Carries over to
diazepam; alprazolam; lorazepam; chlordiazepoxide; oxazepam; temazepam; alcohol; barbiturates; zolpidem

Effectslikely at a common dose

Perception
Dreaming suppression; +6 possible, including Spatial disorientation, Visual acuity suppression, Vestibular distortion
Body
Sedation; Muscle relaxation; Motor control impairment; Physical fatigue; +8 possible, including Dizziness, Respiratory depression, Nystagmus (eye wobbles)
Thinking
Cognitive impairment; Decision impairment; +16 possible, including Analysis suppression, Information processing suppression, Memory suppression
Feeling
Anxiety suppression; Emotional suppression; +2 possible, including Empathy suppression
Self
Disinhibition; +5 possible, including Communication suppression, Craving
Time
none likely · 2 possible, including Temporal disorientation

Who shouldn't take it

Absolute
Severe hepatic impairment; Benzodiazepine hypersensitivity; Narrow-angle glaucoma
Relative
Respiratory compromise; Concurrent valproate use for absence seizures; Substance use disorder history; Pregnancy; Breastfeeding; Elderly; Concurrent opioid use

Combinations60 recorded

Lethal (1)
Opioids
Dangerous (21)
Alpha-2 adrenergic receptor antagonist; Antipsychotics; Atypical antipsychotics; Benzodiazepines; Buprenorphine, Kratom; Cannabis, THC; Clonidine, Guanfacine; Gabapentin, Pregabalin; GHB, Baclofen; GHB, GBL; Local anesthetics; Naltrexone; SNRIs; Stimulants; Synthetic cannabinoids; Ibogaine; Ketamine, DXM, PCP; MAOIs; NSAIDs; Poppers (Alkyl nitrites); Poppers, Nitrates
Caution (26)
See full page: psychedex.org/substances/clonazepam
Not graded (12)
Not listed never means safe.

Seek help immediately if

  • Extreme drowsiness — can't stay awake or be roused
  • Confusion, slurred speech, severe loss of coordination
  • Slow, shallow, or irregular breathing
  • Unconsciousness / unresponsive; limp, floppy body
  • Blue lips or fingertips
  • Vomiting while sedated (choking / aspiration risk)
  • Cold, clammy skin; weak pulse

What to do

  1. Try to wake them — shout, firm sternal rub
  2. If unresponsive or breathing is impaired, call emergency services
  3. Place them in the recovery position — critical, they can choke on vomit
  4. Monitor breathing continuously; be ready to give rescue breaths / CPR
  5. Never leave them alone to "sleep it off"
  6. Do not give other drugs, stimulants, or more depressants

Most depressant overdoses resolve with airway protection, breathing support, and monitoring. The danger is respiratory depression and choking on vomit — sharply worse when combined with opioids or alcohol. GHB/GBL overdoses often involve sudden deep unconsciousness and may self-resolve, but airway protection is essential.

988 Suicide & Crisis LifelineFireside Project: 62-FIRESIDE

Version r1 · Not medical advice

References

  1. [1]
    ^Sankar R (2012) GABA(A) receptor physiology and its relationship to the mechanism of action of the 1,5-benzodiazepine clobazam. — CNS drugs doi:10.2165/11599020-000000000-00000
  2. [2]
    ^Navarrete F, Marín-Mayor M, Martínez-Hostyn L, Rubio G, Manzanares J (2026) Benzodiazepine Dependence: Clinical and Molecular Aspects, Preventive Strategies and Therapeutic Approaches. — International journal of molecular sciences doi:10.3390/ijms27031430
  3. [3]
    ^Dowd SM, Strong MJ, Janicak PG, Negrusz A (2002) The behavioral and cognitive effects of two benzodiazepines associated with drug-facilitated sexual assault. — Journal of forensic sciences PMID:12353555
  4. [4]
    ^National Library of Medicine (StatPearls) (2024) Clonazepam (StatPearls) Link
  5. [5]
    ^Su FY, Tsai MC, Ng YY, Wu SC (2026) The Risk Factors and Mortality Among Patients With Different Combination Patterns of Opioids and Benzodiazepines: A Retrospective Study. — Pharmacology research & perspectives doi:10.1002/prp2.70215
  6. [6]
    ^Teverovsky EG, Gildengers A, Ran X, et al. (2024) Benzodiazepine use and risk of incident MCI and dementia in a community sample. — International psychogeriatrics doi:10.1017/s1041610223000455
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