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    Nimetazepam molecular structure

    Nimetazepam Stats & Data

    Lavol Erimin Hypnon Happy 5 Erimin-5
    PubChem
    MW295.29
    FormulaC16H13N3O3
    LogP2.2
    IUPAC1-methyl-7-nitro-5-phenyl-3H-1,4-benzodiazepin-2-one
    InChIKeyGWUSZQUVEVMBPI-UHFFFAOYSA-N
    Chemical Class 1,4-Benzodiazepine
    Psychoactive Class Depressant

    Receptor Profile

    Receptor Actions

    Modulators
    GABA-A receptor positive allosteric modulator (benzodiazepine site)

    Toxicity

    PubChem

    Benzodiazepines bind nonspecifically to benzodiazepine receptors BNZ1, which mediates sleep, and BNZ2, which affects affects muscle relaxation, anticonvulsant activity, motor coordination, and memory. As benzodiazepine receptors are thought to be coupled to gamma-aminobutyric acid-A (GABAA) receptors, this enhances the effects of GABA by increasing GABA affinity for the GABA receptor.

    Carcinogenicity

    No indication of carcinogenicity to humans (not listed by IARC).

    Effect Profile

    Curated + 3 Reports
    Benzodiazepine 7.3

    Strong anxiolysis and euphoria with strong cognitive impairment, mild sedation

    Anxiolysis×3
    10
    Sedation / Relaxation×2
    5
    Motor / Cognitive Impairment×1
    9
    Euphoria / Mood Lift×1
    10
    Based on reports from:

    Tolerance & Pharmacokinetics

    drugs.wiki
    Half-Life
    14–30 hours (oral; active metabolites, including nitrazepam, may prolong effects)
    Addiction Potential
    Moderate to high. Like other benzodiazepines, regular or high-dose use can lead to tolerance, physiological dependence, and a severe withdrawal syndrome; risk is increased with long-acting agents and polydrug use.

    No tolerance chart. Our decay curves for these drugs were estimates, and a curve can make tolerance look longer-lasting than it is, which is the dangerous direction.

    How fast tolerance to these drugs fades after a break has not been measured well enough to draw, so don't count on a dose you used to take still being safe: after time off, start with a much smaller amount and don't use alone. Mixing sedatives with each other, with alcohol or with opioids sharply raises the risk of a fatal overdose. If you've been using regularly, don't stop suddenly: withdrawal from benzodiazepines, alcohol or GHB/GBL can cause seizures or delirium, so get medical help to cut down gradually.

    Sources: FRANK: benzodiazepines · Alcohol and Drug Foundation: GHB · FDA 2020: benzodiazepine boxed warning · FDA 2019: gabapentinoids and breathing · NHS: alcohol use disorder

    Cross-Tolerances

    Other benzodiazepines

    Experience Report Analysis

    Erowid
    4 Reports
    3 Single-substance
    2005–2010 Date Range
    2 With Age Data
    1 Effects Detected

    Demographics

    Gender Distribution

    Too few reports for a chart: gender is known from 4 reports, and a split is drawn only from 20 reports or more. Counts are shown instead. Why 20?

    • Male 3 of 4
    • Female 1 of 4

    Age Distribution

    Reports Over Time

    Effect Analysis

    Erowid

    Effects aggregated from 3 experience reports (3 single-substance Erowid)

    3 Reports
    1 Effects Detected
    1 Positive
    0 Adverse
    0 Neutral

    Effect Sentiment Distribution

    Confidence Distribution

    Each bar is the share of reports mentioning the effect; its whisker, and the band on the rows below, is the 95% interval: where the share could plausibly be with other reports of the same kind.

    Too few reports for bars: these effects come from 3 single-substance Erowid reports, and a bar is drawn only from 20 reports or more. With fewer, a percentage cannot tell a common effect from a rare one. Counts are shown instead. Why 20?

    Positive Effects 1

    Color Enhancement 3 of 3 70%

    Adverse Effects 0

    Legal Status

    Controlled internationally under the UN Convention on Psychotropic Substances 1971.
    Country Status Notes
    Hong Kong regulated under Schedule 1 of Hong Kong's Chapter 134 Dangerous Drugs Ordinance
    Singapore physician prescribed drug, and is regulated under the Misuse of Drugs Act
    United States categorized Schedule IV FDA and DEA

    Harm Reduction

    drugs.wiki

    Nimetazepam is marketed mainly in parts of Asia (e.g., as 5 mg 'Erimin 5'); non-medical availability often involves counterfeit tablets that may contain other benzodiazepines, making potency unpredictable—assume unknown composition and avoid mixed-source pills unless lab-checked. Next‑day sedation, impaired coordination, and memory gaps are common with long/medium-acting benzodiazepines; avoid driving or operating machinery until at least the day after use and longer if residual effects are present. Combining benzodiazepines with opioids, alcohol, GHB/GBL, or other depressants greatly increases the risk of life‑threatening respiratory depression and fatal overdose; avoid co‑use and never use alone. Tolerance develops quickly with repeated use and can encourage escalation; spacing uses by weeks and avoiding consecutive‑night dosing reduces risk of rapid tolerance. Abrupt cessation after sustained use can cause severe withdrawal (anxiety, insomnia, agitation, tremor, seizures); any taper should be slow and medically supervised. 'Blackout' amnesia can lead to unintentional redosing—pre‑measure a single dose, keep a log, and have a trusted sober person hold the supply if needed. Crushing or injecting tablets is dangerous due to insoluble binders/fillers (risk of vein damage, infection) and unpredictable kinetics; stick to oral use only. People who are pregnant can produce neonates with benzodiazepine withdrawal symptoms; discuss any exposure with a clinician. Older adults and those with renal or general frailty have heightened sensitivity to sedation and falls; lower thresholds and longer spacing are prudent. Reports note nimetazepam may partially metabolise to nitrazepam and has high oral bioavailability with relatively rapid onset—this can increase misuse potential; extra caution with redosing is warranted. In unregulated markets, prioritize drug checking where available; if not, avoid brand‑dependent assumptions (e.g., 'Erimin 5' logo) as authenticity is unreliable.

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