Etonitazene - Substance Search

Summary TheDrug.Wiki

Etonitazene is an extremely potent synthetic opioid discovered in 1957, approximately 1,000-1,500 times stronger than morphine in animal studies but likely 60 times stronger in humans. 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 TheDrug.Wiki

Light Common Strong Heavy

Onset, Duration & After-effects TheDrug.Wiki

ROA	Onset	Comeup	Peak	Offset	After Effects
Oral	5-15 min	15-30 min	1-3 hrs	2-4 hrs	2-6 hrs
Insufflated	2-10 min	10-20 min	1-2 hrs	1-3 hrs	2-4 hrs
Intravenous	1 min	2-5 min	30 min	1-2 hrs	1-4 hrs
Smoked	1-3 min	5-15 min	30 min	1-2 hrs	1-4 hrs

Effect Profile

Scores (1–10) 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

Based on reports from:

Erowid Experience Reports PsychonautWiki Etonitazene

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 2d Half tolerance 3d Baseline ~14d

Pattern approximated from general opioid tolerance behavior (rapid build with repeated dosing; partial decay over 1–4 weeks) and mechanistic mu-receptor downregulation; specific etonitazene human data are lacking. Treat as a conservative harm-reduction estimate; individual variability is large.