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    Disclaimer
    This is a fentanyl analogue active in microgram doses. Accidental overdose can be rapidly fatal. Naloxone should always be on hand.

    Fentanyl

    Aliases: Tnt, Fent, Fenty, Fetty, Actiq

    Summary PsychonautWiki

    Fentanyl (also known as Fentanil and by the brand names Sublimaze, Actiq, Durogesic, Duragesic, Fentora, Matrifen, Haldid, Onsolis, Instanyl, Abstral, Lazanda among others) is a potent opioid substance of the anilidopiperidine class. It is a strong agonist at the μ-opioid receptors and approximately 40 to 50 times more potent than pharmaceutical grade (i.e. 100% pure) heroin and roughly 80 to 100 times more potent than morphine.[citation needed].

    Dose Information TheDrug.Wiki TripSit PsychonautWiki

    ROA Light Common Strong Heavy
    Insufflated 10-25μg 25-50μg 50-75μg 75ug+
    Transdermal 12-25μg 25-50μg 50-100μg 100μg+
    Sublingual 10-25μg 25-50μg 50-75μg 75μg+
    Light Common Strong Heavy

    Onset, Duration & After-effects TheDrug.Wiki TripSit PsychonautWiki

    ROA Onset Peak Offset Total
    Oral 15-30 min 30-90 min 1-2 hrs -
    Insufflated 15-30 min 30-60 min 30-90 min 1.2-3 hrs
    Transdermal 2-4 hrs 12-24 hrs 12-24 hrs 26-52 hrs
    Sublingual 12-30 min 30-90 min 30-90 min 1.2-3.5 hrs

    Opioid MME Calculator

    ⚠ Citation & Disclaimer: Conversion factors sourced from the NIH HEAL Initiative MME Calculator (Adams et al., PAIN 2025), the CDC 2022 Clinical Practice Guideline for Prescribing Opioids for Pain, and the MDCalc MME Calculator. These are approximate equianalgesic ratios for educational reference only. Individual responses vary significantly based on genetics, tolerance, cross-tolerance, and route of administration. This is not medical advice. Do not use these conversions to adjust opioid dosing without professional medical guidance.
    mg
    0.077 mg Fentanyl
    mg Morphine

    ⚠ Equianalgesic dose ratios are approximations and do not account for genetic factors, tolerance, incomplete cross-tolerance, or pharmacokinetic variations. Methadone conversion is especially variable at higher doses. Always consult a healthcare provider before making any changes to opioid therapy.

    Effect Profile

    128 reports

    Scores (1–10) curated from multiple sources:

    • Effect keyword matching from PsychonautWiki catalog
    • Validated against 108 Erowid trip reports
    • Weighted by importance: core (×3), major (×2), minor (×1)

    Full methodology

    Opioid 7.6
    Intense 8/10

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

    Euphoria / Warmth ×3
    7
    physical euphoria cognitive euphoria euphoria

    “I felt as if there was alot of pressure in my head but it felt great, I was a little nervous of nodding and never waking up but effects subsided about 30 minutes later.”

    Spooky_J bluelight

    “No real euphoria present, as is typical with Fentanyl itself, so this wasn't suprising.”

    banonimuss bluelight
    Analgesia ×2
    10
    pain relief analgesia

    “Carfentanyl is stronger hypnosedative under analgesic equivalent doses as fentanyl.”

    p2np bluelight

    “I would attempt to get it turned into powder to smoke...or I would just use it as directed bc I didn't get any high out of slamming it so I think if I had just put it on my skin at least I wouldn't...”

    ChasingTheEscape bluelight
    Sedation / Relaxation ×1
    8
    sedation drowsiness dream potentiation

    “(Cheap, good painkiller, not making me too tired (stimulating me!), easy to have a lifelong supply if you can control their usage a little, not being organotoxic at all, etc..).”

    p2np bluelight

    “I have had these patches for a long time using 3/4 of one without any effects until now 10 minutes/ The feeling was intense no euphoria what so ever but a deep relaxed state i fell into.”

    Spooky_J bluelight
    Itching / Nausea ×1
    6
    nausea constipation dry mouth sweating

    “I think it's called precipitated withdrawals, but that felt worse than slamming H after slamming the Fent patch, you feel instantly nauseous & goose bumps galore & sometimes a headache, instant body...”

    ChasingTheEscape bluelight

    “My friends were really sick , but only my for the longest 2 days of their life's.”

    3dempty bluelight

    User Experience

    pain relief “Carfentanyl is stronger hypnosedative under analgesic equivalent doses as fentanyl.” — p2np, bluelight

    Tolerance

    Build-up develops within days of regular use; analgesic tolerance faster than respiratory depression tolerance
    Reset 7–14 days for partial reset; full reset may take weeks — tolerance loss greatly increases overdose risk

    Tolerance Decay

    Full tolerance 3d Half tolerance 7d Baseline ~21d

    Fentanyl tolerance decays significantly within 1–2 weeks of abstinence. Tolerance to analgesic effects is lost faster than tolerance to respiratory depression, creating a dangerous window where returning to a previous dose can cause fatal overdose. Even brief periods of abstinence (3–5 days) substantially reduce tolerance. Sources: StatPearls Fentanyl (NBK459275), PCSS Opioid Tolerance, American Addiction Centers.

    Cross-Tolerances

    Effects Erowid Bluelight

    Aggregated from 108 Erowid and 20 Bluelight experience reports

    Positive Effects 29

    Euphoria 44.5% 93%
    Sedation 35.2% 89%
    Contentment 35.0% 84%
    Empathy 23.4% 85%
    Anxiety Suppression 20.3% 80%
    Thought Deceleration 20.0% 84%
    Stimulation 19.5% 80%
    Tactile Enhancement 16.7% 70%
    Pain Relief 16.4% 88%
    Body High 15.7% 89%
    Peace 15.0% 87%
    Sociability Enhancement 15.0% 89%
    Focus Enhancement 13.0% 70%
    Music Enhancement 10.2% 70%
    Color Enhancement 10.2% 70%
    Heaviness 10.0% 85%
    Love 10.0% 88%
    Warmth 10.0% 90%
    Joy 10.0% 85%
    Drowsiness 5.0% 85%

    Adverse Effects 27

    Nausea 31.3% 88%
    Vomiting 20.0% 91%
    Confusion 10.2% 70%
    Numbness 10.0% 88%
    Insomnia 10.0% 92%
    Body Load 10.0% 80%
    Hot Flashes 10.0% 85%
    Headache 7.0% 78%
    Motor Impairment 6.2% 86%
    Increased Heart Rate 5.6% 70%
    Memory Suppression 5.6% 70%
    Sweating 5.6% 70%
    Respiratory Suppression 5.0% 95%
    Fear 5.0% 95%
    Panic 5.0% 90%
    Dizziness 5.0% 88%
    Eye Strain 5.0% 75%
    Vibrating 5.0% 85%
    Thought Disorganization 5.0% 88%
    Emotional Blunting 5.0% 85%

    Combinations TripSit

    Pill Identifiers

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