Ketamine: Know your stuff, NZ with KnowYourStuffNZ

Ketamine, kitty, ket, or special K, is a drug that has been growing in popularity both globally and in Aotearoa in recent years.

How ketamine affects an individual, and how much risk of harm it poses, is dependent on many things. To reduce risk, the main things to be mindful of are:

  • Know your drug – get your substance tested and familiarise yourself with what to expect
  • Know your dosage – don’t take too much
  • Know your drug interactions – don’t take two downers at once
  • Know yourself and what you are ready for – known in drug taking communities as “set”, be mindful of your personal wellbeing and medical history
  • Know your environment – known in drug taking communities as “setting”, make sure you are in a safe place

The overall long-term effects of ketamine are yet to be fully understood, and much like any other drug it poses some benefits and some risks of harm. We recommend approaching ketamine with caution and respect.

Safer snorting

People taking ketamine most commonly snort it. This is because ketamine doesn’t cause much effect when swallowed. It is also somewhat commonly injected into the muscles (intramuscular injection – IM), although the preparation and harm reduction advice necessary for doing this safely is beyond the scope of this blogpost. Look out for an upcoming blogpost on more thorough harm reduction advice for intramuscular injection!

Injecting ketamine into the veins (intravenous injection/IV), is strongly not recommended as it results in rapid anaesthesia and will render you unconscious at very low doses, which can be really dangerous.

To protect yourself from as much harm as possible when snorting, we recommend the following:

  • Get your drugs checked by KYSNZ or another drug checking service.
  • Wash your hands and dry them thoroughly.
  • Use a clean and disinfected surface to snort your drugs off of.
  • Measure doses carefully.
  • Crush your substance as finely as possible.
  • Use your own snorting equipment and do not share it with others.
  • Rinse your nose with water before and especially after snorting drugs to reduce inflammation.
  • Don’t take ketamine alone. This is especially important if you are aiming for the k-hole.
  • If you are a sober friend looking after a person intending to k-hole, it is very important you do not leave them alone as ketamine can cause vomiting, and a person in a k-hole may choke on their vomit if left unattended. We’ll be talking more about tripsitting and how to mind your mates in a future post called Set, Setting, and Sitting.

While having a clean and controlled approach to taking drugs in a party environment may get you some odd looks, it is important to think about what harmful bacterium you may be exposing yourself and your communities to – increasingly relevant in a world in the midst of a pandemic. Also, maybe your discomfort during comedowns after a night snorting drugs isn’t just because of the drugs – it could be that harming your sinuses, picking up germs, and a generally weakened immune system have a part to play.

What kind of effects to expect


  • Increased alertness.
  • Mild physical euphoria, lightness, and dizziness.
  • Pain relief.


  • Alcohol-like disinhibition.
  • Anxiety suppression.
  • Pleasurable “pins and needles” sensation.
  • Mild sensory distortions, such as changes in felt bodily form and perception of gravity.


  • More pronounced sensory distortions.
  • “Scattered” focus.
  • Boosts in confidence and creativity.
  • Feelings of insight and clarity that can feel euphoric and compelling. This feeling may result in a tendency to compulsively redose.


  • Hallucinations.
  • Sedation.
  • Excitement and/or agitation.
  • In some people with underlying psychological conditions, states of mania or psychosis may be triggered.

The K-hole:

  • All previously listed effects may be present.
  • Memory suppression – loss of ability to access both short and long-term memories.
  • Sensory suppression – loss of ability to see, taste, smell, hear, and feel.
  • Boundary dissolution – the edges of one’s being becoming seemingly transient. As an example, feeling as though one is “melting into the couch”.
  • Ego death – the above listed effects can all together create an experience in which one feels as though they have lost touch with who they are, both in terms of their body, and their identity or “ego”. This can be experienced as profound and ecstatic to some people, or frightening and dysphoric to others.


This information is a guideline only, not a recommendation, as each individual responds differently to any given substance or dosage of a substance.

Doses for snorting ketamine

By body weight Approx. total
Threshold 0.22mg/kg 10 – 15mg
Light 0.33mg/kg 15 – 30mg
Common .66mg/kg 30 – 75mg
Strong 1.1mg – 1.65mg/kg 60 – 125mg
The K hole 2.2mg/kg 100 – 250mg

Duration of effect for snorting*

Onset 5 – 15 minutes
Duration 45 – 60 minutes
Normal After Effects 1 – 3 hours

*It is worth noting that the durations of effect listed here are for single doses. Additional doses will extend the duration and intensity of effect.
There is a cumulative effect with ket so if you’re trying to avoid the k-hole we recommend reducing the dose of subsequent bumps.

Doses for injecting ketamine into the muscles

By body weight Approx. total

0.22mg/kg 10 – 15mg
Light 0.33mg/kg 15 – 30mg
Common 0.44mg/kg 25 – 50mg
Strong 1.1mg/kg 40 – 100mg
The K hole 1.65mg/kg 60 – 125mg

Duration of effect for injecting ketamine into the muscles

Onset 1 – 5 minutes
Duration 30 – 60 minutes
Normal After Effects 2 – 4 hours

Information sourced from Erowid, December 2021.

Ketamine is fully eliminated from the average adult’s body in about 8-15 hours, although the presence of ketamine may be detectable by some specialised drug tests for over 30 days. It is not a drug that is commonly screened for.

Ketamine interactions: some are remarkably less fun than others.

Overdosing on ketamine alone is very rare. However, when ketamine is mixed with other substances, it can become much more risky.

Substance combined with ketamine Risk level
  • Alcohol
  • Opiates
  • Benzodiazepines Tramadol

  • Z-drugs (zopiclone, eszopiclone, and so on).
  • Sleeping pills (quetiapine, promethazine, and so on)
Dangerous – we highly recommend avoiding these combinations.

  • Alcohol, opiates, benzodiazepines, z-drugs, and GHB/GBL, when mixed with ketamine, have the risk of vomit aspiration – inhaling and choking on vomit, which can be fatal.
  • Tramadol and ketamine both lower seizure thresholds, and should therefore not be combined.
  • Sleeping pills when mixed with ketamine can result in excessive sedation.
  • MAOIs
  • Grapefruit juice
  • Amphetamines
  • Cocaine
Approach with caution, avoid where possible

  • MAOIs, MAO-B inhibitors, and grapefruit juice all appear to increase the absorption of ketamine, and therefore the intensity of effects. This results in unexpected levels of intoxication which can be hazardous.
  • Both cocaine and amphetamines can cause heightened risk of physical injury (through slips and falls), as well as elevated blood pressure.
  • Psychedelics
  • NOS
  • MDMA
Low risk, but still presents potential danger

Psychedelics, NOS and MDMA all act synergistically with ketamine. This means that when ketamine is combined with any of them, the effects of both are intensified. This can be enjoyable to some, and confusing/anxiety inducing to others.

The primary risk of harm is with lowered inhibition, loss of motor coordination, trips, and falls.

For more interactions and their risk levels, visit the Interactions Chart on the Tripsit website

The downside

Ketamine, like all drugs (and most things that feel good), has risks of harm, side effects, and contraindications. Such as:

  • Causing symptoms associated with bladder damage
    An estimated 25% of people who take ketamine recreationally (according to The Global Drug Survey) suffer from bladder damage caused by ketamine. Bladder damage from ketamine can result in urge incontinence, decreased bladder volume, and painful haematuria (blood in urine). If a person taking ketamine is experiencing any of these symptoms they should stop taking ketamine immediately and seek medical advice. Taking ketamine regularly increases the risk of bladder damage.
    Read our blogpost on ketamine and bladder damage.

  • Moderate to high abuse potential for some people
    Some data suggests ketamine may be neurotoxic, if it is taken very regularly and in very high dosages.
    Increased depression and memory impairment in people who take ketamine very frequently (20 days a month). These symptoms are seemingly fully reversible when the person stops taking ketamine, although the effects of psychological withdrawal may further complicate things.

  • May exacerbate or trigger underlying mental health conditions, such as manic, dissociative, and psychotic conditions.
    People who are k-holing are unaware of their surroundings and can be interfered with in harmful ways without knowing.
    Ketamine can cause vomiting and people who vomit while k-holing can choke and asphyxiate. If you are with someone in a k-hole then do not leave them alone. Make sure they are lying in the recovery position, not on their back.


We won’t tell you what drugs you should or shouldn’t take, and how you should or shouldn’t take them. All we wish to do is assist you in making the best informed decisions you possibly can, and encourage you to reflect on ways you could be reducing harm.

Ketamine has a wide range of uses, and when it is used in medical, controlled settings, many of the drug’s negative side effects are avoided or managed. When ketamine is taken for fun, though, without regulations or controlled variables, the potential risks one is exposing oneself to are much higher.

Look out for yourself and your friends. If you’re noticing you are needing to take more and more ketamine to enjoy the same effects, and definitely if you’re noticing things are becoming a bit more difficult in the urinary department, it might be time to put the straw down and have a frank conversation about how you are taking drugs with yourself, your loved ones and/or a medical professional.

Published by Naomi

Naomi is a student and peer support worker/advocate who specialises in the intersections of drug harm reduction, transness, neurodiversity, and addressing the societal determinants of health.

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