How Long Does Ketamine Stay In The Body’s System?

How Long Does Ketamine Stay In The Body’s System?

Drugs differ in the amount of time that they stay present in the body. Some substances can last in the body for a relatively short while, whereas others can stick around for longer. This article focuses on how long ketamine is detectable in your system, specifically via urine and hair. How long the psychedelic stays in your system is not universal, however, as this timeframe can differ depending on various factors.

How Long Ketamine Stays In Your System

The approximate amount of time that ketamine will still be detectable in urine after use is 3-5 days. However, the substance can be detectable in urine tests for up to 14 days and in hair follicle tests for up to 90 days. This shows that there can be a huge variation in the amount of time that the psychedelic stays in the body’s system.

While a urine test and hair follicle test could potentially detect ketamine in the body 14 days and three months after use, respectively, these will just be trace amounts of the drug.

According to Dr. Leonardo Vando, Mindbloom’s Medical Director and a board certified psychiatrist and addiction psychiatrist with over 15 years of experience, “Ketamine metabolizes quickly in the body, with a half-life of around 2.5 hours. This means that after 2.5 hours, 50% of the ketamine is gone from the bloodstream. In comparison, coffee has a half-life of five hours. Given this, after about 10 hours after dosing, very little of the ketamine will still be in a person’s system. This is independent of the subjective experience of ketamine, which subsides in about an hour. You can learn more about how long ketamine lasts on our website.”

However, how long ketamine stays in your system depends on many factors. Dr. Martha Koo, MD of Neuro Wellness Spa in Southern California, says, “The majority of ketamine is out of the body in about 12.5 hours. Factors such as age, drug dosage, body mass, and route of administration also affect elimination time.”

It’s important to note that after taking ketamine, your liver will quickly metabolize the substance into less active metabolites (e.g. norketamine). It is estimated that 94 to 97 percent drug is eliminated from the body after 4-5 half-lives. So, if you’re an adult, most of it will be out of your system around 8-15 hours.

Also, just because ketamine is detectable in your urine or hair, it doesn’t mean that the drug will still have any side effects on you. The effects of the drug typically lasts between 45 to 90 minutes. After this time, ketamine may be present in your system, but you’ll experience no perceptual, psychological, or physical effects from it.

Different Factors Affect The Detectability Of Ketamine

The huge variation in the detectability of ketamine comes down to many different factors. Let’s explore each of these in turn.

Individual Drug Metabolism

Drug metabolism rates vary between individuals. Some people metabolize a drug quickly, whereas, for others, the process can be much slower. Several factors can influence individual drug metabolism rates, including the following.

  • Genetic factors. Your genes predispose you to have a slower or faster metabolic rate than average
  • Co-existing disorders, especially chronic liver disorders, kidney disease, and advanced heart failure. If you deal with any of these health problems, you may experience longer detection times
  • Drug interactions, particularly those that speed up or slow down your metabolism
  • The amount of physical activity you do, with regular exercise increasing your metabolic rate, even when at rest
  • Hormone function. For example, thyroid hormones are involved in diverse metabolic activities, so if you have any thyroid issues, this could affect your metabolism
  • Body mass. People with larger bodies have more metabolizing tissue and therefore a higher metabolic rate
  • Age. As you get older, your metabolism slows down, which can lengthen the time it takes for the body to fully eliminate drugs. So, if you are an older person, you may have a longer detection time after taking ketamine compared to those who are young with a faster metabolism
  • Hydration levels, since drinking water can stimulate your metabolism

Ketamine Dosage

Dosage is another crucial factor that can alter how long ketamine lasts in the body’s system. When taking a small dose of ketamine, it will stay in your body for a much shorter amount of time. Compare this to taking a large dose of the drug, and it changes. Simply put, the larger dose has more material that the body needs to metabolize.

Ask your clinician what their ketamine dosage is before your treatment.


If using ketamine more than once or continuously in a session, then you will just extend the detection time. Also, if frequently using the psychedelic for, say, once or more a week, it is possible that it will always be detectable in your urine to some degree.

Studies also highlight that in chronic drug users, the drug of abuse can be detected in urine for one week after last use. This contrasts with a single dose, in which the drug can be detected in urine after 1-4 days. So, if taking ketamine as a one-off as part of treatment, the drug will stay in your system for a shorter amount of time compared to chronic users.

Route Of Administration

The way in which you take ketamine can also have an effect on detection times. This is because smoking, snorting, swallowing, and injecting drugs can all lead to substantially different concentrations in the body’s system. Moreover, these different routes of drug administration can lead to differences in absorption, metabolism, and excretion rates.

For example, taking ketamine via intravenous (IV) or intramuscular (IM) injection leads to faster absorption of the drug compared to consuming it orally or intranasally. According to Daytryp Health Psychedelic Wellness Centers Founder and CEO, Chris Cohn, ketamine administered intravenously or intramuscularly has “noticeable physical effects within seconds.” He goes on to say, “Patients can feel the therapeutic effects within just a few minutes, much quicker than any SSRI medication, which can take several weeks or months to provide therapeutic benefits to patients.”

For patients taking ketamine at home in a ketamine telehealth session, they are likely to take sublingual tablets, which Dr. Leonardo Vando, Mindbloom’s Medical Director, says:

At-home ketamine therapy sessions facilitated through Mindbloom last about an hour. Clients hold the medicine in their mouth for seven minutes before spitting it out, and often choose to listen to one of our specially-designed audio tracks during their treatment, which are each an hour long. After treatment, clients are generally able to go on with their day, although they should not drive or operate any sort of machinery until they’ve slept.

— Dr. Leonardo Vando, Medical Director of Mindbloom

If you decide to opt for ketamine therapy, you will likely receive intramuscular injections, lozenge and rarely IV. However, some patients with depression use a ketamine nasal spray. Most recreational users will snort the drug.

Generally, if you need to undergo drug testing, you are not likely to take a test that detects ketamine. Standard drug test panels look for cannabis, cocaine, amphetamines, heroin, and PCP. One of the primary reasons for excluding ketamine in a standard drug test is due to cost. Specialized drug testing is necessary to detect the drug.

Besides drug testing, you don’t need to worry about how long ketamine lasts in the body if you are undergoing ketamine therapy. This also is the same if only using the drug occasionally. On the other hand, when abusing the drug and becoming a chronic user, it can stay in your system longer. This kind of use is more likely to lead to physical issues like damage to the organs, particularly the bladder.

As the above shows, several factors are out of your control pertaining to how long ketamine stays in your body. However, other factors are still very much controllable.

Sam Woolfe

Sam Woolfe

View all posts by Sam Woolfe

Sam Woolfe is a freelance writer based in London. His main areas of interest include mental health, mystical experiences, the history of psychedelics, and the philosophy of psychedelics. He first became fascinated by psychedelics after reading Aldous Huxley's description of the mescaline experience in The Doors of Perception. Since then, he has researched and written about psychedelics for various publications, covering the legality of psychedelics, drug policy reform, and psychedelic science.

Dr. Ben Medrano

This post was medically approved by Dr. Ben Medrano

Dr. Ben Medrano is a board certified psychiatrist specializing in Integrative Psychiatry, Ketamine Assisted Therapy and Psychedelic Harm Reduction and Integration. He received his MD from the University of Colorado School of Medicine with additional training in the Urban Underserved Track (CU-UNITE). Dr. Medrano is most known for his work with ketamine assisted therapy and is the former Senior Vice President and US Medical Director of Field Trip Health - the largest in-office ketamine assisted therapy practice to date. He continues to sponsor Field Trip clinics as a local medical director at multiple sites on the East Coast allowing him to further the field of psychedelic assisted therapy and research.

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