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    Disclaimer
    ☠ Nitazene-class opioids are extremely potent, often exceeding fentanyl in strength. Even trace amounts can be fatal. Fentanyl test strips do NOT detect nitazenes — a negative strip does not rule one out. Naloxone works, but often needs repeated doses, and re-sedation can follow once it wears off: call emergency services and stay with the person.
    🧪 This is a research chemical with limited data on its long-term health effects, toxicity profile, and safe dosage ranges.
    ⚠ Opioids carry significant risk of respiratory depression, physical dependence, and fatal overdose. Never combine with other depressants.

    Etonitazene Limited data
    Limited data
    Sparse data. Doses and effects may be unreliable or untested.
    • 1 source
    • no dose data
    • duration data present
    • 29 combo interactions documented
    • classified Research-chemical

    Aliases: Ea-4941, Cs-4640

    Depressant Research-chemical Opioid

    Summary dose.wiki

    Etonitazene is an extremely potent synthetic opioid discovered in 1957, approximately 1,000 times the potency of morphine; in-vivo rodent data place it at or above fentanyl. It was never approved for medical use due to severe dependency potential and respiratory depression. Etonitazene has an unpredictably steep dose-response curve and erratic pharmacokinetics, especially when injected, making it more hazardous than fentanyl.

    Dose Information

    Dose basis. No dose range is published for etonitazene because none is established. It is a microgram-active nitazene opioid many times more potent than fentanyl; a normal milligram scale cannot weigh a dose of it, and batch potency in the unregulated supply varies enormously. Assume full respiratory depression, keep naloxone to hand (repeat doses may be needed), never use alone, and never combine with benzodiazepines, alcohol or other depressants.

    Onset, Duration & After-effects dose.wiki

    ROA Onset Comeup Peak Offset After Effects Total
    Oral 5-15 min 15-30 min 1-3 hrs 2-4 hrs 2-6 hrs 3.33-7.75 hrs
    Insufflated 2-10 min 10-20 min 1-2 hrs 1-3 hrs 2-4 hrs 2.2-5.5 hrs
    Intravenous 36 sec 2-5 min 30 min 1-2 hrs 1-4 hrs 1.54-2.59 hrs
    Smoked 1-3 min 5-15 min 30 min 1-2 hrs 1-4 hrs 1.6-2.8 hrs

    Effect Profile

    Scores (0–10) curated from multiple sources:

    • Effect keyword matching from PsychonautWiki catalog
    • Weighted by importance: core (×3), major (×2), minor (×1)

    Full methodology

    Opioid 7.9
    Intense 8/10

    Strong euphoria and pain relief with moderate itching/nausea, mild sedation

    Euphoria / Warmth ×3
    10
    physical euphoria cognitive euphoria euphoria warmth
    Analgesia ×2
    8
    pain relief analgesia
    Sedation / Relaxation ×1
    5
    sedation muscle relaxation
    ⚠ Itching / Nausea ×1
    6
    nausea constipation
    View methodology →

    Tolerance

    Build-up develops within days of regular use; analgesic tolerance faster than respiratory depression tolerance
    Reset Falls quickly once you stop, at a rate you can't judge. After any break, treat your tolerance as gone.

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

    Opioid tolerance drops fast when you stop, and even a few days off can be enough, so a dose that used to be normal can now stop your breathing. Overdose deaths rise sharply after prison, detox or leaving treatment, and tolerance also falls during a hospital stay. After any break, start with a much smaller amount, try a test dose first, don't use alone, and keep naloxone within reach. Alcohol, benzodiazepines, gabapentinoids and other sedatives make an opioid overdose much more likely.

    Sources: FRANK: heroin · National Harm Reduction Coalition · WHO: opioid overdose · Merrall et al. 2010 · Binswanger et al. 2007 · Strang et al. 2003 · FDA 2019: gabapentinoids and breathing

    Cross-Tolerances

    Other mu-opioid agonists (e.g., heroin, morphine, fentanyl)

    Effects dose.wiki

    Positive
    Negative
    Neutral
    Positive
    Negative
    Positive
    Negative
    Neutral

    Combinations

    Cross-Check Etonitazene with another substance

    Etonitazene's nerd page Pharmacology, chemical data, effect profiles, and more
    →

    Helpful Links

    📖 dose.wiki
    Add to PsychonautWiki Journal

    The PsychonautWiki Journal logging app doesn't include every substance. To track Etonitazene there, start adding an ingestion, search for the name, and choose to add it as a custom substance. Paste these values:

    Name
    Etonitazene
    Unit
    mg
    Description 
    Etonitazene
Source: SubstanceSearch (substancesearch.com)


Oral duration: onset 5-15m · come-up 15-30m · peak 1-3h · offset 2-4h · total 3.33-7.75h · after-effects 2-6h
Insufflated duration: onset 2-10m · come-up 10-20m · peak 1-2h · offset 1-3h · total 2.2-5.5h · after-effects 2-4h
Intravenous duration: onset 36s · come-up 2-5m · peak 30m · offset 1-2h · total 1.54-2.59h · after-effects 1-4h
Smoked duration: onset 1-3m · come-up 5-15m · peak 30m · offset 1-2h · total 1.6-2.8h · after-effects 1-4h

Note: ranges are harm-reduction guidance, not a prescription. Start low, go slow, and test your substances.

    The app keeps custom substances simple, so the full dose ranges live in the description text above. Ranges are harm-reduction guidance, not a prescription.