In studies performed on children, researchers detected ketamine for up to two days in urine samples. Ketamine metabolites lasted even longer. You might metabolize the drug faster or slower depending on your age, organ health, and more.
Ketamine appears in most drug tests for several days. That’s important, as some people need ketamine drug tests to prove they’ve been drugged (or “roofied”) before an assault.
But you might use ketamine at a music festival and have a job interview the next day. While ketamine is sometimes prescribed to treat depression, it’s illegal to use without a prescription. Use the drug illegally, and you could be disqualified for the job you want.
Ketamine Effects: How Long Do They Last?
The effect of ketamine is rapid, taking only a few minutes for a user to begin feeling its effects. A ketamine high typically lasts for about 30 to 60 minutes. This differentiates it from similar drugs, which may affect a person for hours after use.
Common ketamine side effects include the following:
- Feelings of detachment or disassociation
- Memory loss
In rare cases, a user may experience hallucinogen persisting perception disorder (HPPD) several weeks after use. When this occurs, a user may experience some of the negative hallucinogenic effects of ketamine that occurred with their initial use.
Ketamine use can be detected in the body days or even weeks after use if the appropriate tests are used. Typically, urine testing works best to detect use within about a week, and hair testing works best for detection of use over longer periods.
|Time Since Use||Effect|
|Initial dose||The drug will take effect within minutes, distorting a person’s perceptions and making them feel disconnected from their body. The person will generally feel sedated and immobile. They will experience partial or total amnesia of events that occur after taking the drug.|
|10–20 min||Heart rate and blood pressure typically increase and then gradually decrease over this period.|
|30–60 min||Effects will gradually strengthen and then fade away, with a user regaining more of their faculties until their high fades completely.|
|6–9 days||Typically, ketamine can be detected in a person’s urine for about this length of time, with properly targeted testing. Use is possible to detect in urine for longer but with less reliability.|
|90 days||This is typically considered the maximum length of time ketamine (and most drug use) can be detected in a person’s hair.|
Researchers sometimes use the concept of half-life when discussing drugs. A half-life represents how long it takes your body to process or eliminate half of the dose you took. Ketamine’s half-life is about 45 minutes.
Testing for Ketamine
Drug testing takes many forms. Typically, a testing agency takes a sample from your body and looks for the presence of ketamine or its metabolites.
Notably, ketamine is not a drug that is often tested for in a typical drug test. Most drug testing looks for commonly abused drugs, including marijuana, opioids, and alcohol. For a test to have any chance of detecting ketamine use, it must be designed for that purpose.
Four main types of testing formats exist, which are as follows:
Testing for drug use through hair is one of the most accurate ways to test use over time and to detect drug use that occurred weeks or more in the past.
Research has suggested a cutoff window of 0.5 ng/mg is best for detecting repeated ketamine use. 
Drug testing in this way is only possible once the patient’s hair has grown out, but it can provide accurate results for multiple months after drug cessation.
It is possible to test for ketamine use through urine, with the right testing methodology able to detect use for about six days after use with reasonable reliability. Notably, this doesn’t guarantee detection.
While urine tests can be used to detect illicit drug use, they can also be helpful for detecting if a person may have been victimized using the drug. Urine testing is typically how people are tested for ketamine use unless information about a person’s history of drug use is the goal, in which case hair testing is used.
Blood testing for ketamine use is rare but still available. Urine testing is generally preferred as it is less invasive.
Blood testing can have a longer detection period, however, with at least one company advertising an accurate detection window of about 7 to 14 days. Chronic drug use potentially extends that detection window.
A saliva test is easy to administer, and it’s not invasive. Tests like this can detect ketamine for 24 to 48 hours.
Factors That Impact How Long Ketamine Stays in Your System
A number of factors can influence how long a person’s drug use can be detected. These include the following:
- Dose taken
- Frequency of use
- Your age
- Physical health, including kidney and liver function
- Test used
In general, the more drugs a person takes over a shorter period, the easier it is to detect some trace of their drug use.
Getting Help for Ketamine
With repeated use, your brain and body become accustomed to ketamine. Try to quit, and you’re likely to feel difficult symptoms like mood swings and insomnia. Detox can help.
In medical detox, treatment teams offer proven medications in a calm environment, allowing your body and mind to adjust to sobriety safely. Boca Recovery Center offers medically proven treatment plans to help you stop using ketamine and start living your best life.
Frequently Asked Questions About Ketamine Withdrawal
We’ve compiled some of the most frequently asked questions about ketamine abuse and testing.
How long does ketamine stay in your system?
You may no longer feel intoxicated within about an hour, but ketamine can show up on tests for up to 90 days.
What is ketamine prescribed for?
Some doctors use ketamine to help patients with depression that can’t be addressed by other medications.
What type of drug is ketamine?
Ketamine is a hallucinogenic drug. It changes the way you view the world around you.
How does ketamine work?
Ketamine alters chemical levels within the brain, distorting visual and auditory information and making you feel detached from reality.
Does ketamine treat depression?
Some doctors use ketamine therapy to address depression symptoms that don’t respond to conventional forms of therapy. It’s generally not the first choice for people with depression.
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