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    Phenazepam molecular structure

    Phenazepam Stats & Data

    Fenaz Panda Bonsai Soviet benzo Bromdihydrochlorphenylbenzodiazepine
    NPS DataHub
    MW349.61
    FormulaC15H10BrClN2O
    CAS51753-57-2
    IUPAC7-bromo-5-(2-chlorophenyl)-1,3-dihydro-1,4-benzodiazepin-2-one
    SMILESO=C1CN=C(c2ccccc2Cl)c2cc(Br)ccc2N1
    InChIKeyCGMJQQJSWIRRRL-UHFFFAOYSA-N
    2020/3. Benzodiazepine; 2021/3. Benzodiazepine; 2022/3. Benzodiazepine
    Chemical Class Benzodiazepine
    Psychoactive Class Depressant
    Half-Life ~60 hours (long-acting; functional effects can persist 1–3+ days).

    Receptor Profile

    Receptor Actions

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

    Effect Profile

    Curated + 11 Reports
    Benzodiazepine 6.6

    Strong anxiolysis and cognitive impairment with moderate euphoria, mild sedation

    Anxiolysis×3
    10
    Sedation / Relaxation×2
    5
    Motor / Cognitive Impairment×1
    10
    Euphoria / Mood Lift×1
    6

    Tolerance & Pharmacokinetics

    drugs.wiki
    Half-Life
    ~60 hours (long-acting; functional effects can persist 1–3+ days).
    Addiction Potential
    High. Like other benzodiazepines, phenazepam readily produces tolerance, dependence, and a withdrawal syndrome that can include seizures; the long half-life may mask escalating dependence while causing accumulation.

    Tolerance Decay

    Full tolerance 14d Half tolerance 7d Baseline ~30d

    Based on general benzodiazepine patterns and user reports: noticeable tolerance can develop with repeated use over days to weeks; partial reversal over 2–4 weeks of abstinence. Individual variability is high; data are anecdotal.

    Cross-Tolerances

    Diazepam
    100% ●●○
    Clonazepam
    100% ●●○
    Other benzodiazepines (class)
    100% ●○○

    Experience Report Analysis

    Erowid
    11 Reports
    2009–2019 Date Range
    11 With Age Data
    6 Effects Detected

    Demographics

    Gender Distribution

    Age Distribution

    Reports Over Time

    Effect Analysis

    Erowid

    Effects aggregated from 11 experience reports (11 Erowid)

    11 Reports
    6 Effects Detected
    3 Positive
    2 Adverse
    1 Neutral

    Effect Sentiment Distribution

    Confidence Distribution

    Positive Effects 3

    Sedation 36.4% 70%
    Euphoria 36.4% 70%
    Anxiety Suppression 36.4% 70%

    Adverse Effects 2

    Memory Suppression 36.4% 70%
    Confusion 27.3% 70%

    Real-World Dose Distribution

    62K Doses

    From 15 individual dose entries

    Oral (n=12)

    Median: 2.0mg 25th: 1.0mg 75th: 4.25mg 90th: 5.0mg
    mg/kg median: 0.034 mg/kg 75th: 0.065

    Form / Preparation

    Most common forms and preparations reported

    Redose Patterns

    Redosing behavior across 10 reports

    10.0% Redosed
    1.1 Avg Doses

    Benzodiazepine Equivalence

    1.0 mg Phenazepam = 10.0 mg Diazepam
    Potency ratio 10.0

    Phenazepam - ~1mg ~=10mg Diazepam.

    All other CNS depressants.

    Legal Status

    Controlled internationally under the Single Convention on Narcotic Drugs 1961.
    Country Status Notes
    China As of October 2015, phenazepam is a controlled substance in China.
    United Kingdom Phenazepam is a class C drug in the UK. The UK home office banned importation of phenazepam on Friday 22 July 2011 while it drafted legislation, released in January 2012 to become law at the end of March 2012. The bill was quashed following advice from the ACMD as it included two non-abusable steroids. There was a new discussion about its fate on April 23, 2012, where it was decided that the bill would be rewritten and phenazepam would still be banned. It was eventually banned on June 13, 2012 as a class C, schedule II drug.
    United States Under federal United States law, phenazepam is not currently classified as a controlled substance, as the Federal Analog Act only provides for automatic assumed classification of chemicals "substantially similar" to existing Schedule I or Schedule II drugs, whereas all controlled benzodiazepines under the Controlled Substances Act are classified as Schedule IV. Although phenazepam is currently not controlled, sale for human use remains illegal in the United States. Suppliers attempt to circumvent this regulation by placing a "Not for human use" disclaimer on the product's label. Individual states in the United States often ban these analog drugs by name as they appear. Since 2012, Louisiana has classified phenazepam as a controlled dangerous substance. This ban affects several products, some of which were sold at retail stores under the guise of air freshener or similar, containing phenazepam yet claiming not to be for human use. This legislation was introduced after one such product, branded as "Zannie" and marketed as an air freshener rapidly gained publicity as the subject of numerous media reports, attracting the attention of officials. The ensuing investigation effort, led by Senator Fred Mills and Louisiana Poison Center Director Mark Ryan, positively identified the active ingredient of "Zannie" as phenazepam. According to Ryan, chemical analysis identified the active ingredient as "100 percent phenazepam". Paul Halverson, director and state health officer for the Arkansas Department of Health, approved an emergency rule to ban the sale and distribution of phenazepam shortly after the Louisiana ban. Alabama made Phenazepam a schedule I substance on March 18th, 2014.

    Harm Reduction

    drugs.wiki

    • Phenazepam is a long‑acting benzodiazepine; TripSit’s benzo table lists an approximate 60 h half‑life, meaning effects and impairment can persist into the following days and accumulate with redosing. Plan doses with a multi‑day horizon and avoid daily use. • Relative potency is high: TripSit lists ~1 mg phenazepam ≈ 10 mg diazepam orally. Start at the low end (0.5–1 mg) and reassess after full onset; do not assume diazepam-like margins. • Because it is active at sub‑milligram to low‑milligram levels, eyeballing powder routinely leads to blackouts and multi‑day amnesia; use a 0.001 g scale and volumetric dosing. Numerous community harm‑reduction threads document severe consequences from mismeasurement. • Onset can be slow (up to 1–1.5 h or longer); redosing before the first dose peaks is a frequent cause of overdose and prolonged blackout. Wait several hours before considering any additional dose. • Avoid insufflation and injection: phenazepam is poorly water‑soluble and reports describe unreliable absorption and delayed effects by non‑oral routes, compounding overdose risk. • Polysubstance risk is high: combining benzodiazepines with alcohol, GHB/GBL, opioids, or tramadol markedly increases sedation and respiratory‑depression risk; if someone becomes unresponsive, place them in the recovery position and call emergency services. Do not attempt home reversal. • Counterfeit or mislabelled tablets are common in illicit markets (e.g., “Xanax/Valium” pressed with other benzos); use drug checking where available and be prepared for unexpected strength or different substances. • Benzodiazepine withdrawal can be severe and potentially life‑threatening; do not abruptly stop after extended or high‑dose use. Seek medical support for a gradual taper. (General benzo harm‑reduction guidance.) • Long half‑life plus amnesia increases risk of unsafe behaviors (driving, online purchases, interpersonal conflict) during multi‑day blackouts; secure access to the supply, log dose/time, and enlist a trusted sober person if needed. Community reports repeatedly describe multi‑day blackouts. • Cross‑tolerance with other benzodiazepines is expected; those with existing benzo tolerance may perceive little effect at low doses but still accrue impairment and dependence. • In some regions, benzodiazepines appear in opioid supplies (e.g., bromazolam/nordiazepam found in checked fentanyl samples), increasing overdose risk; test supplies and carry naloxone (note: naloxone does not reverse benzodiazepines).

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