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I
Opioids

Isotonitazene ('Iso')

Street names: Iso, Isotonitazene, ITZ

Isotonitazene ('Iso') — Yellow/off-white powder; pressed into counterfeit pills

What it does

  • Nitazene-class opioid — fentanyl-comparable potency, long legs

Key risks

  • 2020–2022 US midwest wave; detected in counterfeit oxycodone and heroin
  • Naloxone works — multiple doses
  • Missed by standard screens
  • Often found WITH fentanyl and xylazine in the same sample

Overdose signs

  • Respiratory depression
  • Cyanosis, unresponsive
  • Re-sedation after naloxone

📋Quick facts

Also known asIso, Isotonitazene, ITZ
CategoryOpioids
Schedule / classSchedule I (US, 2022)
AppearanceYellow/off-white powder; pressed into counterfeit pills
Street priceContaminant/adulterant pricing
Legal statusSchedule I US; controlled EU/UK/CA
Last updated2026-09-18
Sources: DEA, EMCDDA, NIDA

Category comparison — Opioids

SubstanceClassTop risksStreet price
Isotonitazene ('Iso')Schedule I2020–2022 US midwest wave; detected in counterfeit oxycodone and heroin; Naloxone works — multiple dosesContaminant/adulterant pricing
EtonitazeneSchedule I~10–25× fentanyl potency; Active at sub-milligram doses — nearly impossible to dose safely~$40–$100/g
MetonitazeneSchedule IDrove 2021 US east-coast overdose waves; detected in 'dope' and counterfeit pills; Standard drug screens miss it — hospitals often don't know what reversed themMixed into bags — no separate street price
Street prices are regional estimates. Potency and cuts vary constantly.

?Frequently asked questions

What does Isotonitazene ('Iso') look like?

Yellow/off-white powder; pressed into counterfeit pills

What are the signs of a Isotonitazene ('Iso') overdose?

Respiratory depression; Cyanosis, unresponsive; Re-sedation after naloxone Call emergency services immediately and give naloxone if available — it reverses opioid overdoses.

How addictive is it?

2020–2022 US midwest wave; detected in counterfeit oxycodone and heroin Dependence can develop with regular use.

🔗Sources & further reading

Facts on this page are compiled from these primary sources. External links open in a new tab.