Compound: protonitazene, etonitazene, isonitazene, metonitazene, etodesnitazene (etazene), clonitazene, N-Desethyletonitazene + many more!
Other names: Benzimidazole Opioids, Nitazenes
Download Nitazenes flyer here

Nitazenes, also known as benzimidazole opioids, are a are highly potent class of synthetic opioids which vary widely in potency. Some nitazenes, including protonitazene and etonitazene, are more potent than fentanyl and thus pose a very high risk of overdose. Nitazenes were first synthesised in the late 1950s but never reached the market as medicines. Since the early 2010s, synthetic opioids have flooded the drug market in the United States and have significantly contributed to opioid-related overdoses and deaths. Beginning in 2019, nitazenes have been detected in forensic laboratories across the United States, Canada, Europe and Australia.

Know Your Body & Mind — ‘Set’

Know Your Environment — ‘Setting’

Know Your Drug — Practice Harm Reduction

Most commonly swallowed or injected but can also be shelved (rectal) and snorted.

Duration and Half Life is dependent on the type of nitazene and differentiate between onset, peak and total durations. Research the specific one you are taking. The duration of effects may also differ depending on the routes of administration.
Even though the apparent effects of the drug may have worn off, nitazenes can stay active for a long period of time (up to a couple of days) depending on what type. Do your research and remember this if taking other drugs!



The effects of nitazenes are similar to other opioids, but they can be anywhere from 2 to 1000 times more potent than morphine. The effects of nitazenes vary from person to person but can include:


Drug Checking: Lab-quality testing for detecting Nitazenes is recommended and is available in Canberra (ACT) and in Brisbane & Gold Coast (QLD). However even with specialised chemistry equipment, detecting nitazenes in drug samples can be difficult since they are often present in extremely small amounts (e.g., a few milligrams). Unfortunately, fentanyl test strips are unable to detect nitazenes.
Nitazene overdoses in Australia have been linked to counterfeit pharmaceutical pills such as Xanax, Kalma pills and Oxycodone. They have also shown up in samples of heroin and ketamine.

Carrying nitazenes and paraphernalia (e.g. injecting/smoking equipment) puts you at risk of criminal charges including trafficking, even if you don’t deal. As of May 5 2024 Queensland is introduced police drug diversion for minor drug possession offenses involving personal use amounts of some drugs. Know your local laws e.g. Drugs Misuse Regulation 1987 (QLD)Police Powers and Responsibilities Regulation 2012, the Drugs Poisons and Controlled Substance Act 1981 (Vic).

Physical effects


  • Pain Relief
  • Decreased heart rate
  • Decreased blood pressure
  • Warm sensations in extremities
  • Lethargy
  • Drowsiness
  • Constipation
  • A ‘rush’ of warmth
  • Constricted (“pinpoint”) pup
  • Slowed breathing


    • Unconsciousness
    • Vomiting
    • Nausea
    • Sensitivity to light
    • Irregular menstruation
    • Respiratory depression / failure
    • Muscle spasms
    • Death


  • Risk of coma
  • Bluish fingers, toes, lips
  • Brain damage due to respiratory depression

Emotional effects


  • Euphoria
  • Feeling of wellbeing
  • Contentment
  • Relief of anxiety
  • Confusion
  • Depression (when it’s over)
  • Emotional numbness

Psychological effects


  • Decreased sexual desire



  • Paradoxical reaction (energetic movements, noises)


  • Use around friends/people you trust and in a safe environment – somewhere you feel comfortable  
  • Wait at least 30mins after eating before taking.
  • Each nitazene is different, and strength can vary greatly so start with a small dose.
  • When prescribed by a doctor, medications come with dosage instructions.
  • Carry naloxone. Depending on your state you can either buy naloxone over the counter in a pharmacy with/without a prescription. QuIHN’s NSP service also offer free naloxone training and then you receive a free take home one with you.
  • If you’re taking the drug orally, use as per recommended packaging if available, otherwise start with a very small amount.


  • Injecting nitazenes may pose a greater risk of overdose as the lethal dose may be many times smaller than when ingested orally
  • Avoid Blood Borne Viruses ‘BBVs’ (eg. Hepatitis C, HIV) by using new & sterile syringes & equipment.
  • Use sterile water to mix up.
  • Wash your hands thoroughly before and after, you can also use an alcohol swab to clean your fingertips.
  • Alcohol wipes can reduce the risk of skin infections if they are used correctly. For maximum effect, swab once, in one direction on the injection site, and leave to dry naturally.
  • Dispose of syringes & equipment responsibly in a yellow disposal bin, all NSPs have bins available.


  • Avoid sharing straws or pipes to prevent sharing blood borne viruses such as Hep C.
  • Keep your lips moisturised to avoid cracking/bleeding.
  • Clean your pipe regularly by soaking in boiling water for a few minutes.


  • Abscesses (effects of poor injecting practice)
  • Infected heart valves
  • Pneumonia
  • Collapsed veins
  • Blood borne viruses ie.Hep B and C
  • Decreased liver function
  • Cirrhosis (scarring of the liver) as a result of chronic Hepatitis (Hep C)
  • Dependence both physical and psychological.
  • Withdrawal Symptoms can begin within hours of your last use and include: sneezing, excessive yawning, coughing, sweating, chills, restless legs,irritability, moodiness, insomnia, severe muscle & bone pain, diarrhea, increased urination, dehydration, anxiety, nausea, vomiting, cramps, involuntary spasms, sensitive genitals (females).

Safe disposal of equipment

  • Needles and glass pipes should always be disposed of responsibly to avoid accidents like needlestick injuries.
  • Sharps containers are available at all Needle and Syringe Programs (NSPs).
  • If you can’t get a yellow sharps container, put the used sharp/glass into a solid plastic bottle and put the lid on before returning to an NSP.
  • New sterile syringes can be picked up, and used needles & syringes can be disposed of where the NSP symbol is on display or yellow sharps bins.

For more harm reduction information regarding safe injecting:

Drug combinations

Possible outcomes. What works for one person may not work for another. We recommend you proceed with caution.

Unsafe combinations

  • Alcohol – increases sedation and can lead to unconsciousness and aspiration (choking on vomit).
  • Benzodiazepines – increases sedation and can lead to unconsciousness and aspiration.
  • Ketamine – vomiting & risk of unconsciousness.
  • MXE – can increase the effects of heroin.
  • DXM – CNS depressant causing breathing difficulty, heart issues, possible opioid tolerance reduction.
  • Cocaine – stimulant increases respiration rate allowing higher tolerance of opioids. If stimulant wears off before opiate, chance of opioid overdose.
  • GHB/GBL- increases sedation and can lead to unconsciousness and aspiration.
  • Tramadol – CNS depressant, increases risk of seizures in people taking other opioids.
  • Lyrica and other anticonvulsants – Can reduce breathing and heart rate leading to hypoxia.
  • Some Antihistamines eg Phnergan or Unisom – Can reduce breathing and heart rate leading to hypoxia.

Cautionary combinations

  • PCP – can reduce opioid tolerance, increasing the risk of overdose.
  • N2O – increases effects, risk of unconsciousness, memory blackouts are likely.
  • Meth/Amphetamines – stimulant increases respiration rate allowing higher tolerance of opiates. If stimulant wears off before opiate, chance of opiate overdose.
  • MAOIs – has been associated with rare reports of severe and fatal adverse reactions.

Low risk effects

  • Psychedelics – The combination is unlikely to cause any adverse or undesirable reaction beyond those that might ordinarily be expected from these drugs.
  • Cannabis – A lower risk combination which can sometimes cause synergy between the two substances.

Check out the TripSit drug combinations chart here for info on other combinations.

Call 000 if experiencing adverse effects, feel unwell or concerned in any way


This educational resource has been developed collaboratively by healthcare workers and people who use drugs for their peers and the wider community. The role of Hi-Ground is to provide practical, evidence-based, unbiased information to assist you to make educated choices and to promote harm reduction, community care, and wellbeing. In an unregulated market it’s impossible to know the purity or dose of any substance. Taking drugs from an unregulated market carries its own risk, and you can educate yourself and practice harm reduction to reduce this risk.

Knowledge is power.

This resource is produced by DanceWize & Hi-Ground