Isotonitazene Review Intro to "Isoto"nitazene โ I had an idea but wasn't entirely sure what to expect since most descriptions I'd read of nitazenes were vague: most zenes have a strong rush, then some are sedating while others are weirdly stimulating for an opioid. Duration varies from ~1hr-1day+.
Isotonitazene
Encyclopedic
Encyclopedic
Typical encyclopedia coverage. Cross-reference for important decisions.
- 3 corroborating sources
- 2 ROAs with full dose ladders
- duration data present
- 19 combo interactions documented
- classified Research-chemical
- dose data not in PW/TripSit (unverifiable)
Encyclopedic
Typical encyclopedia coverage. Cross-reference for important decisions.
- 3 corroborating sources
- 2 ROAs with full dose ladders
- duration data present
- 19 combo interactions documented
- classified Research-chemical
- dose data not in PW/TripSit (unverifiable)
Aliases: Iso, Toni
Summary
Isotonitazene (CAS 14188-81-9) was first characterized in illicit markets in 2019 and scheduled by the U.S. DEA in 2020. In vitro it shows sub-nanomolar MOR efficacy and produces more prolonged respiratory depression than equipotent fentanyl.
Dose Information
Dose basis. The dose figures on this page are not clinical data. They are aggregated from community reports by a secondary source whose own notes state there is no human pharmacokinetic study behind them, and our internal audit flags this substance's dosing as unverifiable. Treat them as a rough orientation, not a safe range. This is a microgram-active opioid: a normal milligram scale cannot weigh a dose of it accurately, and a weighing error here is measured in lethal multiples rather than percentages. Volumetric dosing is the only defensible method, and batch-to-batch potency in the unregulated supply varies enormously. Assume full respiratory depression, keep naloxone to hand, never dose alone, and never combine with benzodiazepines, alcohol or other depressants.
| ROA | Light | Common | Strong | Heavy |
|---|---|---|---|---|
| Insufflated | 40-80ยตg | 80-150ยตg | 150-300ยตg | 300ยตg+ |
| Oral | 100-250ยตg | 250-500ยตg | 500-1000ยตg | 1000ยตg+ |
Light
Common
Strong
Heavy
Onset, Duration & After-effects
| ROA | Onset | Peak | Offset | Total |
|---|---|---|---|---|
| Insufflated | 2-5 min | 0.5-2 hrs | 2-3 hrs | 2.53-5.08 hrs |
| Oral | 15-30 min | 0.5-2 hrs | 2-4 hrs | 3-8 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)
Opioid
7.0
Strong+
7/10
Strong euphoria, itching/nausea, and pain relief with low sedation
Euphoria / Warmth
×3
10
physical euphoria
intense opioid euphoria
cognitive euphoria
warmth
Analgesia
×2
8
analgesia
pain relief
Sedation / Relaxation
×1
3
sedation
Itching / Nausea
×1
10
itching
nausea
constipation
Add to PsychonautWiki Journal
The PsychonautWiki Journal logging app doesn't include every substance. To track Isotonitazene there, start adding an ingestion, search for the name, and choose to add it as a custom substance. Paste these values:
⬇ Download import file
Import this file as custom substances
and you get "Isotonitazene (Substance Search)" with every
route's full dose ladder and timeline, no typing. Works on iOS and
Android (v15+); the format is confirmed by the app's
developer. The manual values below work for older
versions.
Name
Isotonitazene
Unit
ยตg
Description
Isotonitazene Source: SubstanceSearch (substancesearch.com) Insufflated dose (ยตg): threshold 20-40 ยท light 40-80 ยท common 80-150 ยท strong 150-300 ยท heavy 300+ Oral dose (ยตg): threshold 100 ยท light 100-250 ยท common 250-500 ยท strong 500-1000 ยท heavy 1000+ Insufflated duration: onset 2-5m ยท peak 0.5-2h ยท offset 2-3h ยท total 2.53-5.08h ยท after-effects 12h Oral duration: onset 15-30m ยท peak 0.5-2h ยท offset 2-4h ยท total 3-8h ยท after-effects 12h Note: ranges are harm-reduction guidance, not a prescription. Start low, go slow, and test your substances.
Tip: for quicker logging you can also add a Custom Unit in the app, e.g. common dose ~ 115 ยตg (Insufflated).
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.
Tolerance
Build-up
develops within days of regular use; analgesic tolerance faster than respiratory depression tolerance
Reset
7โ14 days for partial reset; full reset may take weeks โ tolerance loss greatly increases overdose risk
Tolerance Decay
Half tolerance
7d
Baseline
~14d
Operationally, frequent use (daily or near-daily) produces rapid escalation of required doses within a week and marked loss of tolerance after short abstinence; relapse doses after breaks pose high overdose risk. Data quality is mixed: preclinical PK/PD studies plus clinical/toxicology case series and community reports.
Cross-Tolerances
Effects
Positive
- Analgesia
- Physical euphoria
- Pain relief
Negative
- Itching
- Respiratory Depression
- Nausea
- Sedation
- Miosis
- Itchiness
Positive
- Intense Opioid Euphoria
- Reduced anxiety
- Cognitive euphoria
- Anxiety suppression
- Wakefulness
- Motivation enhancement
Negative
- Constipation
- Severe Dysphoria
- Compulsive redosing
- Motivation suppression
Positive
- Warmth
- Increased music appreciation
- Increased libido
Negative
- Appetite suppression
- Light sensitivity
- Disinhibition
- Dehydration
- Dulled perception
- Internal hallucination
- Warm flush
Combinations
Cross-Check Isotonitazene with another substanceCommunity Trip Reports
Anecdotal first-person accounts from Reddit, Erowid, and Bluelight. Click a source to expand. Reports are harm-reduction context, not medical guidance. Tags summarise each author's own verdict — how reports are classified.
Bluelight 1 thread 1 neutral visit
Isotonitazene's nerd page
Pharmacology, chemical data, effect profiles, and more
→
Helpful Links
Report an issue or suggest an edit
Spotted incorrect or dangerous information, have a correction, a new study, or a useful addition for Isotonitazene? Let us know. Reports are reviewed by moderators — this is not posted publicly.