Summary
Metonitazene is a high-potency synthetic benzimidazole opioid with potency similar to fentanyl (approximately 100 times morphine by central routes, 10 times orally). It has been found unexpectedly in counterfeit oxycodone pills, heroin, and other substances. Overdoses may require higher-than-normal doses of naloxone and multiple administrations to reverse. Insufflation is extremely caustic to nasal tissue (pH as low as 2). Use in combination with other depressants greatly increases the risk of fatal respiratory depression.
Dose Information
Light
Common
Strong
Heavy
Onset, Duration & After-effects
| ROA | Onset | Peak | Offset |
|---|---|---|---|
| Oral | 5-15 min | 30-90 min | 2-4 hrs |
| Insufflated | 1-5 min | 30-90 min | 2-4 hrs |
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
Effects
Positive
- Analgesia
- Physical euphoria
- Pain relief
- Muscle relaxation
Negative
- Respiratory depression
- Itching
- Nausea
- Sedation
- Pinpoint pupils
- Itchiness
Positive
- Reduced anxiety
- Cognitive euphoria
- Anxiety suppression
- Wakefulness
- Motivation enhancement
- Euphoria
Negative
- Constipation
- Drowsiness
- Compulsive redosing
- Motivation suppression
Positive
- Warmth
- Increased music appreciation
- Increased libido
Negative
- Appetite suppression
- Light sensitivity
- Disinhibition
- Dehydration
- Dulled perception
- Warm flush
- Internal hallucination