Home
    Disclaimer
    SL-164 molecular structure

    SL-164 Stats & Data

    Dcq
    NPS DataHub
    MW319.19
    FormulaC16H12Cl2N2O
    CAS3476-88-8
    IUPAC5-chloro-3-(4-chloro-2-methylphenyl)-2-methylquinazolin-4-one
    SMILESClc1ccc(c(C)c1)n1c(C)nc2cccc(Cl)c2c1=O
    InChIKeyKUIHLOHNUGOCTO-UHFFFAOYSA-N
    Others
    Chemical Class Benzodiazepine
    Psychoactive Class Depressant
    Half-Life Unknown in humans; functional duration typically 4–6 h with residual sedation.

    Effect Profile

    Curated
    Benzodiazepine 7.1

    Strong anxiolysis, cognitive impairment, and euphoria with mild sedation

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

    Tolerance & Pharmacokinetics

    drugs.wiki
    Half-Life
    Unknown in humans; functional duration typically 4–6 h with residual sedation.
    Addiction Potential
    Moderate; sedative-hypnotic class shows quick tolerance and risk of dependence with repeated use; cross-tolerance with other GABAergic hypnotics likely.

    Tolerance Decay

    Full tolerance 3d Half tolerance 14d Baseline ~28d

    Patterns inferred from sedative-hypnotic class (methaqualone/benzodiazepines) and anecdotal reports of rapid tolerance; figures are heuristic and low confidence. Space uses by multiple days to reduce risk.

    Cross-Tolerances

    methaqualone
    60% ●○○
    benzodiazepines
    40% ●○○
    barbiturates
    40% ●○○
    Z-drugs
    30% ●○○

    Harm Reduction

    drugs.wiki

    Pharmacology is presumed similar to methaqualone: a quinazolinone that potentiates GABAA receptors via transmembrane sites, which explains sedation, motor impairment, and synergy with other depressants. This mechanism predicts additive respiratory depression when combined with alcohol, opioids, benzodiazepines, barbiturates, or GHB/GBL—combinations strongly linked to fatal overdoses in the depressant class. Multiple user reports and forum moderator warnings describe prominent myoclonic jerks/twitching and, at higher doses or with redosing/mixes, seizures; this risk appears greater than with many prescribed hypnotics. Delayed onset (often 60–90 minutes) has led some to redose prematurely; stacking increases adverse effects and blackout risk. Several reports note that even small amounts of alcohol can abruptly potentiate effects; avoid any co-depressants. Insufflation is frequently described as caustic with unpredictable absorption and more abrupt adverse effects; oral use with accurately weighed doses is safer from a harm-reduction standpoint. Because this is an unregulated RC, potency and identity may vary by batch; reagent kits may not distinguish quinazolinones reliably, and only accredited drug checking (GC/MS, LC-MS) can confirm contents—these services also have detection limits and sampling caveats. If someone becomes unresponsive or severely sedated, keep the airway clear and use the recovery position while calling emergency services; do not give additional depressants. If seizures occur, do not place anything in the person’s mouth; seek emergency care—benzodiazepines are used in clinical settings by professionals, but unsupervised self-administration can worsen respiratory depression. Expect residual sedation and psychomotor impairment the next day; avoid driving or hazardous tasks until fully recovered. Frequent use can produce tolerance and withdrawal-like rebound (anxiety/insomnia), so leave multi-day gaps and avoid daily dosing.

    ← Back to SL-164