ketamine and syringe

Last published: November 22, 2023

What is ketamine?

Ketamine is used by medical practitioners and veterinarians as an anaesthetic. It’s sometimes used illegally by people to get high.

Ketamine is a dissociative drug, which means it acts on different chemicals in the brain to produce visual and auditory distortion, and a detachment from reality.

When it’s sold illegally, ketamine usually comes as a white or off-white powder. It can also be made into pills, or dissolved in a liquid.1

Clinical trials and studies are assessing ketamine as a treatment for depression. Early indications show good results.2

Other names

Special K, K, ket, kitkat, super k or horse trank.3,4

Other types of dissociatives

How is it used?

Ketamine can be swallowed, snorted or injected. It’s also sometimes smoked with cannabis or tobacco. The effects of ketamine may be experienced within one minute if injected, 5–15 minutes if snorted, and up to 30 minutes if swallowed. Its effects can last for around an hour, however an individual’s coordination or senses may be affected for up to 24 hours after initial use.4

Effects of ketamine

There is no safe level of drug use. Use of any drug always carries some risk. It’s important to be careful when taking any type of drug.

Ketamine affects everyone differently, based on:

  • size, weight and health
  • whether the person is used to taking it
  • whether other drugs are taken around the same time
  • the amount taken
  • the strength of the drug (varies from batch to batch)

The following effects may be experienced:

  • feeling happy and relaxed
  • feeling detached from your body (‘falling into a k-hole’)
  • visual and auditory hallucinations
  • confusion and clumsiness
  • increased heart rate and blood pressure
  • slurred speech and blurred vision
  • anxiety, panic and violence
  • vomiting
  • lowered sensitivity to pain3,4,6


If you take a large amount of ketamine or have a strong batch, you could overdose.

The risk of death from ketamine alone is low, due to its ability to cause unconsciousness with minimal impact on airway reflexes or blood circulation.5 However, individuals are at a higher risk of physical harm/accidents while under the influence of the ketamine.5

Call an ambulance straight away by dialling triple zero (000) if you or someone else has any of these symptoms (ambulance officers don’t need to involve the police):

  • inability to move, rigid muscles
  • high blood pressure, fast heartbeat
  • convulsions
  • unconsciousness and ‘near death’ experiences
  • death. 3,6,5

Coming down

The day after using ketamine, you may experience:

  • memory loss
  • impaired judgement, disorientation
  • clumsiness
  • aches and pains
  • anxiety.3,6,6

Long-term effects

Regular use of ketamine may eventually cause:

  • flashbacks
  • poor sense of smell (from snorting)
  • mood and personality changes, depression
  • poor memory, thinking and concentration
  • abnormal liver or kidney function
  • ketamine bladder syndrome (see below)
  • abdominal pain
  • needing to use more to get the same effect
  • dependence on ketamine
  • financial, work and social problems3,6

Ketamine bladder syndrome

Large, repeated doses of ketamine may eventually cause ‘ketamine bladder syndrome’, a painful condition needing ongoing treatment.

Symptoms include difficulty holding in urine, incontinence, which can cause ulceration in the bladder.

Anyone suffering from ketamine bladder syndrome needs to stop using ketamine and see a health professional.3

Mixing ketamine with other drugs

The effects of taking ketamine with other drugs– including over-the-counter or prescribed medications – can be unpredictable and dangerous.7-9

Low risk
Ketamine + psilocybin These drugs can work together to increase effects.
Ketamine + nitrous oxide (nangs) These drugs can work together to increase effects.
Ketamine + MDMA These drugs can work together to increase effects.
Ketamine + LSD These drugs can work together to increase effects.
Ketamine + cocaine Impaired coordination, risk of increased blood pressure.
Ketamine + methamphetamine Impaired coordination, risk of increased blood pressure.
Ketamine + GHB/GBL Impaired coordination, nausea, vomiting, passing out, and possible death.
Ketamine + opioids Nausea, vomiting, passing out, and possible death.
Ketamine + benzodiazepines Impaired coordination, nausea, vomiting, passing out at high doses, and possible death.
Ketamine + alcohol Impaired coordination, nausea, vomiting, passing out, and possible death.

‘Polydrug use’ is a term for the use of more than one drug or type of drug at the same time, or one after another. Polydrug use can involve both illicit drugs and legal substances, such as alcohol and medications.

Find out more about polydrug use.

Reducing harm

There are ways in which you can reduce the risks associated with using Ketamine:

  • Start with a lower dose until you know how the drug affects you personally. It will be different for everyone due to factors such as weight, tolerance and metabolism.
  • Avoid using alone.
  • Avoid mixing other drugs with ketamine, especially alcohol.
  • Make sure the drug is crushed into a fine powder so it doesn’t cause cuts.
  • Don’t use bank notes to snort, have your own straw or spoon so you can avoid infection and blood borne viruses.
  • Snorting drugs repeatedly over time can injure the nose, remember to take breaks.
  • You can snort water before and after use to reduce infection risk.
  • Avoid driving, operating machinery or swimming as ketamine slow reflexes and impairs coordination.
  • Consider the impact of your mood and the environment you are in before you use ketamine.
  • Consider having a person to 'trip sit'. A person who remains sober and that can help out if needed.7-9


Giving up ketamine after a long time is challenging because the body has to get used to functioning without it. Please seek advice from a health professional. Symptoms include:

  • cravings for ketamine
  • no appetite
  • tiredness
  • chills, sweating
  • restlessness, tremors
  • nightmares, anxiety, depression
  • irregular and rapid heartbeat
  • risk of inujry3

Getting help

If your use of ketamine is affecting your health, family, relationships, work, school, financial or other life situations, or you’re concerned about a loved one, you can find help and support.

Call the National Alcohol and Other Drug Hotline on 1800 250 015 for free and confidential advice, information and counselling about alcohol and other drugs

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Legally produced ketamine is a restricted substance and only a doctor or vet may prescribe or administer it. All other ketamine is illegal in Australia.

Federal and state laws provide penalties for the illegal use, possession, production, selling or driving under the influence of ketamine. Penalties can include fines, imprisonment and disqualification from driving.

See also, drugs and the law.


  • 3.1% of Australians aged 14 years and over have used ketamine one or more times in their life.11
  • 0.9% of Australians aged 14 years and over have used ketamine in the previous 12 months.11

Young people

  • Young Australians (aged 14–29) first try ketamine at 20.4  years on average.11
  1. United States Drug Enforcement Agency Administration. Ketamine 2020 [03.06.2021].
  2. Zarate C Niciu M. Ketamine for depression: evidence, challenges and promise. World Psychiatry. 2015;14(3):348–50.
  3. Morgan C Curran H. Ketamine use: a review. Addiction 2011;107(1).
  4. Darke S, Lappin, J. & Farrell, M. The Clinician's Guide to Illicit Drugs. United Kingdom: Silverback Publishing 2019.
  5. Kalsi S Wood D Dargan P. The epidemiology and patterns of acute and chronic toxicity associated with recreational ketamine use. Emerging Health Threats Journal 2011;4.
  6. Li L and Vlisides P. Ketamine: 50 Years of Modulating the Mind. Frontiers In Human Neuroscience 2016;10.
  7. Harm Reduction Victoria. Ketamine n.d. [cited: 23.11.2022].
  8. Hi-Ground. Ketmaine n.d. [cited: 23.11.2022]. Available from:
  9. Psychonaut Wiki. Ketamine 2022 [cited: 24.11.2022].
  10. Janssen-Cilag Pty Ltd. Australian Product Information SPRAVATO® esketamine hydrochloride  NSW2021 [10.06.2021].
  11. Australian Institute of Health and Welfare. National Drug Strategy Household Survey 2019 2020 [09.09.2020].

Explore dissociatives on the Drug Wheel

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anxiety, blurred vision, clumsiness, confusion, feeling detached from your body, feeling happy, feeling relaxed, hallucination, increased blood pressure, lowered sensitivity to pain, panic, slurred speech, violence, vomiting


horse trank, K, ket, k-hole, kitkat, special K, super k