How Long Does Ketamine Stay in Your System?

As a leading provider of peace of mind and legally-instructed drug tests, we are often asked how certain drugs affect the body, and how long they can remain in your system.

While not as widely used as cannabis or cocaine, ketamine remains among the most common recreational drugs used in Ireland.

For a 2022 report published by the Health Research Board titled, Drug use among students in higher education in Ireland, over 11,500 students (postgraduate and undergraduate aged 18 and over) were surveyed about their recreational drug use.

Out of those who participated in the study, 16 per cent admitted to having used ketamine, making it the fourth most common recreational drug used by students after cannabis (52 per cent), cocaine (25 per cent) and ecstasy (23 per cent).

In this article, we take a closer look at ketamine, what it is, how it affects the body and how to spot the signs of someone who might be misusing ketamine.

What happens in the body when you take drugs?

When a person consumes drugs, they are broken down by the liver, and a proportion of the drug and its metabolites are released into the bloodstream.

Some of the drug and its metabolites can then be detected in the body in different ways including via sweat, urine, saliva, hair and nails.

In the case of hair and nails, a proportion of the drug and its metabolites travel to the blood vessels in the hair follicles and nail bed.

Substances then become trapped in the hair shaft (medulla) and the keratin fibres of the nails, remaining in hair and nails as they grow, and making it possible to determine whether someone has consumed drugs, using hair and/or nail testing.

What is ketamine?

Ketamine, also known as Ket or Special K, is a general anaesthetic used by veterinarians as an animal tranquiliser. It is also used by medical practitioners to provide pain relief to patients.

Often sold as a light brown or grainy white powder, it is popular among habitual drug users, and is often ingested by snorting, swallowing in pill form, or injecting.

Ketamine is categorised as a controlled substance under the Misuse of Drugs Act (MDA), making the possession, production, sale, or supply of ketamine (for non-medical reasons) illegal in Ireland.

What does ketamine do to you?

It’s important to remember that drugs affect different people in different ways, so not everybody will have the same experience while using the same substances. Drugs can even affect the same person differently when taken at a different time.

How a person’s body reacts to ketamine use depends on many factors including body mass, metabolism, how much they take, and how often they use it.

Because ketamine is a general anaesthetic, one of the greatest risks of ketamine use is the fact that it can reduce the sensations in your body.

This means that if a person injures themselves while using ketamine, they may not know it, which can be dangerous.

Low doses have been known to cause dizziness, euphoria, and confusion, while higher doses can cause nausea, hallucinations, difficulty standing or moving, and a feeling of disconnection between the body and mind.

How long does ketamine stay in your system?

When a person uses ketamine, a proportion of the drug and its metabolites are released into the bloodstream, with a small amount being excreted by the body in a variety of ways.

How long ketamine remains in a person’s system depends on how much they have taken and how often they use it, along with their weight and metabolism.

What factors affect how long ketamine stays in your system?

Factors that affect how long ketamine stays in your system include:

  • Quantities taken
  • Frequency of use
  • Metabolism and weight
  • Method used to ingest the drug – for example, whether it has been snorted, swallowed or injected

How long does it take for ketamine to show up in a drug test?

Ketamine use can be detected by a drug test long after the effects of the drug have worn off.

This is because, once the body has broken down the drug, a small amount of the drug and its metabolites remain in the system, before being eliminated from the body in a variety of ways.

For oral fluid (saliva) drug tests, ketamine remains detectable 24-48 hours after use, while urine drug tests provide a detection window of up to four days.

The rate at which head hair grows means that head hair drug tests provide a wide window of detection for ketamine use, making it possible to detect metabolites in the hair for up to 12 months of continuous use, depending on the length of the hair.

Similarly, nail drug testing can be used to provide an overview of up to 12 months for drug use (six months for fingernails and 12 months for toenails).

Is ketamine addictive?

Ketamine is a general anaesthetic used as an animal tranquiliser in veterinary settings, as well as by doctors providing pain relief to patients.

Because of its painkilling properties, the effects of ketamine – which can include a numbing feeling and hallucinations, depending on how much is taken – can be extremely addictive.

Worse still, individuals who use ketamine regularly can quickly build up a tolerance, meaning that even more of the drug is required to get the same ‘high’.

This can lead to the user developing a harmful addiction.

What are the long-term effects of ketamine use?

Although its physiological effects only last from 30 minutes to one hour, depending on how much the person has taken, ketamine can cause several long-term physical and psychological problems if it is used regularly.

Long-term effects of ketamine can include:

  • Liver and/or kidney damage
  • Impaired sense of smell and/or damage to the nasal cavity (if snorted)
  • Damage to the veins, muscles, and skin (if injected)
  • Urinary tract and/or bladder problems
  • High blood pressure
  • Increased heart rate
  • Seizures
  • Paranoia
  • Mood swings
  • Confusion
  • Memory loss

What are the signs of ketamine addiction?

Ketamine addiction can take many forms, and symptoms vary wildly from person-to-person.

However, there are some common signs you can look out for if you suspect a friend or family member might be struggling with ketamine addiction.

These include:

  • Regular use, especially on a day-to-day basis
  • Feeling unable to stop taking ketamine, even though it is affecting their life
  • Spending an increasing amount of time seeking out and using ketamine
  • Being secretive or defensive about their ketamine use
  • Neglecting personal responsibilities including relationships, family, and work
  • Behavioural changes including mood swings

There are many helpful resources online for individuals struggling with ketamine addiction, as well as for friends and family members affected by a loved one’s ketamine use.

How can I find out if a friend or family member is using ketamine?

An AlphaBiolabs Home Drug Testing Kit, makes it easy to test for drug use at home, with only a urine sample required.

Available for just €20, the non-invasive kit has been designed to give you peace of mind or enable you to seek support for a friend or loved one who has been abusing drugs.

For confidential advice on whether this test is right for you, call our friendly and discreet Customer Services team on 01 402 9466 or email

Please be aware that our Home Drug Testing Kit is for peace of mind only and the results cannot be used in court. If you require a drug test for legal matters, you will need a legally-instructed drug test.

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