Ketamine illustration


K, Ket, Special K, Kit-Kat

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Ketamine is a hallucinogenic dissociative and anaesthetic that is used in both humans and animals for medical purposes. It was synthesised in 1962, and used in anaesthesia as an alternative to phencyclidine (PCP) which caused powerful, long lasting hallucinations and psychotic symptoms. Today it is often used as an anaesthetic in children or those undergoing minor surgery. It is most frequently used now in veterinary medicine. It is on the World Health Organisation’s list of essential medicines.

In low doses, users report a similar feeling to being drunk. Higher doses cause a much more dissociative or psychedelic effect. When used as a medicine, ketamine is a clear liquid. “Street” ketamine is usually a white powder; with a grainy appearance like salt, or flaky like tiny glass shards.


No alcohol

Don’t mix ketamine with alcohol; this can have dangerous sedating effects.


In company

Make sure you are with someone who is sober.


Safe setting

Ketamine can make you incoordinated and confused, putting you at risk of injury. You should avoid driving or being in a public place when you take the drug.

Effects of ketamine

Here are the most common effects, not everyone necessarily experiences all of them every time they consume the drug and other effects not listed might be felt. The likelihood of experiencing negative effects is far greater at high doses.

The effects are (from positive to negative):

  • Increase in energy
  • Euphoria
  • Sense of calm and serenity
  • Meaningful spiritual experiences
  • Enhanced sense of connection with the world (beings or objects)
  • Distortion or loss of sensory perceptions
  • Closed and open eyes visuals
  • Dissociation of mind from body- in large doses users may experience a “k-hole” which is an intense out-of-body or near-death like experience with very realistic visuals.
  • Changes in how you perceive time
  • Pain relief/numbness
  • Shifts in perception of reality
  • Slurred speech
  • Some short term memory loss may occur- and this is worse for regular users!
  • Nasal discomfort when snorting
  • Discomfort, pain or numbness at injection site (only when injected)
  • Severe confusion, disorganised thinking
  • Paranoia (with regular use)
  • Nausea and vomiting
  • Frightening or untimely distortion
  • Loss of control of body movements and balance. Becoming uncoordinated, finding it difficult to move around
  • Sever dissociation, depersonalisation
  • Loss of consciousness(may be dangerous in certain situations)
  • Depression of heart rate and respiration


Dose and onset of ketamine

How? How much? When? For how long?

As with any drug, the correct dose for you depends on factors such as weight, gender, metabolism, whether you have taken the drug recently or not, amongst many others.

Read our section on dosing and tolerance for more information.

How you take ketamine matters...


Snorting is the most common way of using it. People usually divide the powder out into lines with a card and snort it with a straw or a piece of paper. Snorting through one nostril over a long time can lead to nasal ulcers or damage the septum.


Ingesting ketamine results in slightly different effects to snorting or injecting. If taken as a ‘bomb” (wrapping a dose in a cigarette paper) the effects take longer to feel and the experience will last longer. Taking ketamine orally usually results in a less intense experience.

Drinking is another way of doing it. You can dissolve the crystals/powder in a small amount of water and acidic juice (e.g. citrus or apple).

Gumming is another less common way of doing it. A small amount is applied on the inside of the lips or gum. This can damage your gums and lips. Gumming is not a common way of taking ketamine as most users find the taste very unpleasant.

Intramuscular injection

Injection is the most harmful way to take it. Like all other substances mentioned on our website- it’s recommended that you do not inject ketamine. Injecting also increases the likelihood of becoming addicted to a substance.

How much ketamine?


  • Light dose: 15-30 mg
  • Common dose: 30-75 mg
  • Strong dose: 75-150 mg
  • Heavy ("K-hole"): 150+ mg


  • Light dose: 50-100 mg
  • Medium dose: 100-300 mg
  • Strong dose: 200-450 mg
  • Heavy ("K-hole"): 500+ mg

Intramuscular injection

  • Light dose: 15-30mg
  • Medium dose: 25-50mg
  • Strong dose: 40-100mg
  • Heavy ("K-hole"): 60-125mg

Source: Erowid

When do the effects of ketamine kick in and for how long?

The START time below is when you will usually begin to feel the effects of ketamine from the time when you first take it. The DURATION is roughly the length of time you will experience the effects, after which the effects will start to wind off and you might start to feel the calm-down/comedown down effects.

Snorted ketamine timeline

  • START: 5-15 minutes
  • DURATION: 45-60 minutes

Oral ketamine timeline

  • START: 15-25 minutes
  • DURATION: 1-2 hours

Injected ketamine timeline

  • START: 1-5 minutes
  • DURATION: 1-2 hours

You will feel after-effects for 1-3 hours after taking it.

Ketamine may have an anti-depressive effect in low doses (20-30mg), and there are currently a number of ongoing research trials looking into this.

Sources: and

How often can I take ketamine?

If you know of any good source containing this information please email us to . We'll credit you in our Team section! Thanks :)

Interactions of ketamine

Ketamine + ? =

Select a drug

Click one of the drugs below and see how it mixes with Ketamine.


Harm reduction for ketamine

There are certain precautions you should take before doing ketamine. The advice below helps you to be physically and mentally prepared before doing it. Furthermore, we want you to be safe, and just in case you have a bad experience or some of the unwanted side effects associated with ketamine, we have also provided information on how to take care of yourself when you are in full swing. Finally, there are those uncomfortable or undesirable effects after the high have worn out, we will provide you with some practical tips on how to have a better calm down and help you to reduce the harm done to your body and brain.

Head over to our ME section if you would like to know more about harm reduction.



  • Good hygiene can also reduce harm. If you are snorting ketamine, ensure you use a clean surface and an unused straw. Sharing straws or using notes can put you at risk of infections.
  • Regularly snorting any drug can damage your nose. If you are going to snort ketamine, make sure it is crushed finely. Afterwards, clean your nose with water.



  • You should avoid food for at least 1.5 hours before taking ketamine. Nausea and vomiting can occur when coming up. Staying still can help with this feeling.


  • Injecting ketamine causes damage to the skin and veins, leading to sores. Sharing injecting equipment risks infections such as HIV, Hepatitis B and Hepatitis C. Injecting street ketamine carries further risks as it is likely to contain other substances which may increase harm. If you are going to inject ketamine, use only medical grade ketamine liquid and always use new injecting equipment. Free needle and syringe exchange services are available around the UK. They provide sterile injecting equipment as well as advice to users.


  • It’s very important to think about where you take ketamine. On high doses or in a K-hole, it is very difficult to move around, which puts you in a vulnerable position. It’s best to ensure you are in a safe and familiar place if you are going to take it. It is a good idea to be with someone who is familiar with the drug. You might become quite confused and also be injured if you try to move around when taking the drug.


  • If you are feeling unwell after taking ketamine in a party, look for your friends. They will help you feeling better. Tell them how you feel and ask them for anything that might make you feel better such as water.


  • It is very important to avoid driving while on ketamine. Not only is this very dangerous, it is also illegal. The drug driving limit for ketamine is 20 micrograms per litre of blood.


Whilst death from ketamine poisoning is quite uncommon, it is still possible to overdose. Signs of a ketamine overdose include:

  • Feeling sick and/or vomiting
  • Feeling very confused
  • Chest pain and irregular heart rate
  • Being unable to move
  • Violence or becoming very frightened (this may be due to hallucinations)
  • Loss of consciousness or coma
  • In severe cases, ketamine can cause you to have a fit. In some cases, people have choked on their vomit when unable to move or unconscious.
  • Raised blood pressure

If you think you or a friend has taken an overdose of ketamine, it is very important to seek help immediately. Call an ambulance and tell them what has been taken so that medical staff can help. You won’t get into trouble for this and you may minimise or prevent any serious long-term damage.


Although the major effects of ketamine only last about 1-2 hours before users feel normal, some people have longer lasting subtle effects that might last for a couple of days. Maintaining a healthy lifestyle is important to your physical and mental wellbeing, so try to make sure that you eat well, get enough sleep, and try to get some exercise.

Some people take ketamine to forget about problems in their everyday life. While this might work for a short time, it can encourage people to take ketamine more and more often which can cause a range of physical and psychological effects.

Check and compare anonymously your drug use with the Drugsmeter ketamine app .

Risks of Ketamine


Ketamine can have long term effects, both physically and mentally when consumed regularly.

Urinary problems

Long term use of ketamine can lead to urinary problems. In the most serious of cases, this may result in the removal of the bladder. If you use ketamine and experiencing any pain or difficulties in urinating, stop use immediately and seek advice from your GP. Some people take more ketamine to help with this pain, however this may cause further, more serious damage. Learn more about bladder damage from ketamine use.

There is some evidence that drinking green tea before consuming ketamine may have protective effects but this was performed in rats.

Long term memory problems

Ketamine has been shown to interfere with memory, learning and attention. Some users have also described having flashbacks after taking the drug.


Ketamine has a high potential for abuse and while it is not physically addictive, it can cause psychological dependence in some users. Tolerance to the effects of ketamine develops quite quickly, so user need to use more and more of the drug to get the same effects as when they started using.

Read more about dependence here.

When you want to quit

If you decide to stop using ketamine, you may experience some unwanted withdrawal effects. If you do, it is a good idea to speak to a health professional who will be able to support you and signpost you to helpful services.

Some of the withdrawal effects of ketamine may include:

  • Cravings
  • Anxiety
  • Shaking
  • Sweating
  • Fast heart beat

Don't hesitate to look for medical help, you won't get in trouble. Talk to your GP, who will be able to refer you on to your local addiction service.

There are other several advice services available online and over the phone including:

The Law on Ketamine


  • Belgium: It is legal for medical and veterinary use and illegal when sold or possessed without a prescription.
  • Czech Republic: It is legal for medical and veterinary use and illegal when sold or possessed without a prescription.
  • Denmark: It is legal for medical and veterinary use and illegal when sold or possessed without a prescription.
  • France: Ketamine is a Schedule IV drug.
  • Germany: It is legal for medical and veterinary use and illegal when sold or possessed without a prescription.
  • Norway: Ketamine is a Class A drug.
  • Slovakia: Ketamine is a Schedule II drug.
  • Sweden: Ketamine is a Schedule IV drug.
  • UK: Ketamine is a Class B drug. Ketamine was reclassified to a Class B drug in the UK in 2014. The UK Advisory Council on the Misuse of Drugs made this recommendation based on the chronic harms associated with ketamine use.


  • Brazil: The drug is legal for veterinary use and illegal when sold or possessed for human use.
  • Canada: Ketamine is a Schedule I drug.
  • Mexico: Ketamine is a Category 3 drug.
  • USA: Ketamine is a Schedule III drug.

Asia and Oceania

  • Australia: Ketamine is a Schedule IV drug.
  • China: Ketamine is a Schedule II drug.
  • Hong Kong: Ketamine is a Schedule I drug.
  • Malaysia: The possession and sale is illegal.
  • New Zealand: Ketamine is a Class C drug.
  • Singapore: Ketamine is a Class A drug.
  • South Korea: The possession and sale is illegal.
  • Taiwan: Ketamine is a Schedule III drug.

More information, references, useful links...


Is ketamine a horse tranquiliser?

Ketamine is used as a safe anaesthetic in humans and also in many animals- not just horses. When first developed, it was for humans and used in certain situations where it might not be practical to use other anaesthetics that depress breathing. It is widely used in medical emergencies as a painkiller or as an anaesthetic in developing countries.

If ketamine is used for medicine, then will it be safe for me?

Ketamine is used in medical settings as a safe anaesthetic and painkiller. However, recreational use may not always be safe. Medical ketamine will be pure, whereas street ketamine may contain dangerous adulterants. In a recreational setting, ketamine can make you feel detached from your surroundings. You may find it difficult to move, which may put you in a vulnerable position or lead to injury. Long term use can also have serious effects, including damage to the bladder and urinary tract.

Useful links

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  • Jansen, K. L. R 1993. Non-medical use of ketamine. British Medical Journal, 306, 601-602.

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