Ketamine typically clears the system of people who take it within one to three days. However, it can show up on drug tests for longer because ketamine breakdown products called metabolites are left behind. A standard drug screening panel won’t detect ketamine, but specialized tests can. 

How Long Does Ketamine Last?

When taken as prescribed, ketamine is an injectable drug that starts acting quickly. If given intravenously, it starts working within seconds; if injected into a muscle, it starts working within four minutes. The effects then last 15 to 30 minutes.

At recommended doses, the drug relieves pain and causes sedation. When abused or taken at high doses, however, it causes dissociative effects that distort your perceptions and make you feel like you are outside your environment. When abused, the drug is snorted, smoked or taken orally. Ketamine is often mixed with illicit drugs like cocaine or ecstasy, and it has been implicated in sexual assaults. When ketamine is abused, its effects can start within minutes and can last anywhere from 30 to 60 minutes.

Half-Life of Ketamine

The half-life of ketamine is around 45 minutes. It takes five half-lives to eliminate a drug from your system, so this means in a healthy adult, the average elimination time for ketamine is about three hours and 45 minutes. This is an average, so everyone is going to be a little different regarding how long it takes their body to eliminate ketamine. However, it is important to remember that ketamine can show up on a drug test for much longer.

Does Ketamine Show Up on a Drug Test?

Ketamine can show up on drug tests. However, it is important to note that ketamine is not part of a standard drug test. Nonetheless, doctors or employers can order specialty tests for ketamine if they suspect a person has been taking the drug. These tests are widely available and can check for the presence of ketamine in the system.

How Long Does Ketamine Stay in Your System?

Ketamine can stay in different parts of the body for varying lengths of time. Some parts of your body where ketamine can be found include:

  • Urine: Ketamine and its breakdown product norketamine can be found in urine. The drug can be detected anywhere from a couple of days to several weeks after the last use, depending on how much ketamine the person took. Larger doses of ketamine may be found in the urine for longer than smaller doses.
  • Blood: Although ketamine can be detected in blood, blood tests for ketamine are uncommon. However, it takes ketamine about 2.5 hours to move from the bloodstream into the tissues of the body, which likely reflects the time it can be found in blood.
  • Hair: Ketamine can be found in hair around seven to 10 days after the drug was taken. It can then be detected in hair for around 90 days.
  • Saliva: Ketamine can be found in saliva for up to 48 hours after it was last taken.
  • Breast milk: Ketamine may be found in breast milk, but there is very little data about how much ketamine ends up in milk or how safe it is for a breastfed baby. For this reason, ketamine should be avoided during breastfeeding. If the drug must be used, the baby should be monitored closely for sedation and impact on feeding.

Factors That Influence How Long Ketamine Lasts in Your System

Individual factors like age, body mass, genetics, liver function and overall health all play a role in how long ketamine stays in your system. Ketamine is likely to leave the system of a young, healthy person more quickly than an elderly person. 

Most ketamine is excreted in urine, so someone who is hydrated may get rid of the drug more quickly than someone who isn’t well hydrated. A person’s metabolic rate is an important factor as well. The faster someone’s metabolism, the more quickly they’re going to eliminate drugs such as ketamine.

Related Topic: How long does it take for weed to leave your system

Additionally, the higher the dose someone uses of ketamine, the longer it will take the system to eliminate the drug. How often someone uses ketamine can be relevant.

If you or a loved one struggles with ketamine, you are not alone. Ketamine addiction treatment is available and can be an option for you or your loved one. Contact The Recovery Village today to learn more about ketamine addiction treatment programs that can work well for your situation.

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Editor – Jonathan Strum
Jonathan Strum graduated from the University of Nebraska Omaha with a Bachelor's in Communication in 2017 and has been writing professionally ever since. Read more
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Medically Reviewed By – Dr. Jessica Pyhtila, PharmD
Dr. Jessica Pyhtila is a Clinical Pharmacy Specialist based in Baltimore, Maryland with practice sites in inpatient palliative care and outpatient primary care at the Department of Veteran Affairs. Read more

Sassano-Higgins, Sean; Baron, Dave; Juarez, Grace; Esmaili, Neevon. “A Review of Ketamine Abuse and Diversion”>A Review[…]and Diversion.” Depression & Anxiety, June 22, 2016. Accessed July 17, 2022.

Mobile Health. “What Drug Panel Should I Choose?”[…]uld I Choose?” Accessed July 17, 2022.

U.S. National Library of Medicine. “Ketamine”>Ketamine.” Drugs and Lactation Database (LactMed), February 15, 2021. Accessed July 17, 2022.

RequestATest. “Ketamine Urine Drug Test”>.” Accessed July 17, 2022.

RequestATest. “Ketamine (Special K) Hair Drug Test</[…]pa[…]air Drug Test.” Accessed July 17, 2022.

Mandrioli, Roberto. “The Double Face of Ketamine—The Possib[…]nd Beverages.” Molecules, February 2021. Accessed July 17, 2022. 

AlphaBioLabs. “Ketamine Drug Testing – Does Ketamine […]n a Drug Test?” Accessed July 17, 2022.

U.S. National Library of Medicine. “Ketamine Hydrochloride Injection”[…]ide Injection.” DailyMed, June 17, 2022. Accessed July 17, 2022.

Hallare, Jericho; Gerriets, Valerie. “Half Life”>Half Life.” StatPearls, August 23, 2021. Accessed July 17, 2022.

Rosenbaum, Steven B.; Gupta, Vikas; Palacios, Jorge L. “Ketamine”>Ketamine.” StatPearls, November 20, 2021. Accessed July 17, 2022.

Drug Enforcement Administration. “Drugs of Abuse”>.” 2020. Accessed July 17, 2022.

Medical Disclaimer

The Recovery Village aims to improve the quality of life for people struggling with substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare providers.