How Long Does Ketamine Stay in Your System?
Ketamine is administered by injection into a vein (intravenous or IV) or muscle (intramuscular or IM). A ketamine nasal spray has also been recently approved by the FDA for the treatment of patients with treatment-resistant depression.8 At lower doses ketamine produces pain relief and sedation, while at higher dosages the drug produces dissociation and hallucinatory effects. The effects appear within seconds when the drug is given IV, whereas it can take up to 4 minutes for the onset of action when given IM.7
Depending on how it is administered, the effects of ketamine can last anywhere from 5 to 30 minutes. Following administration, ketamine is quickly metabolized by the liver into less active metabolites. Approximately 90% of ketamine is excreted in the urine in the form of metabolites.9 The half-life of ketamine, which is the time it takes for the total amount of drug in the body to be reduced by 50%, is about 2.5 hours in adults and 1 to 2 hours in children.10
From a clinical standpoint it is estimated that a drug is effectively eliminated after 4-5 half-lives, meaning the majority of ketamine should be out of the system of an adult in about 10 to 12.5 hours. Factors such as age, body mass, metabolic rate, drug dosage, and route of administration can affect the duration and elimination of the drug.7
A study published in the International Journal of Legal Medicine found that ketamine can be detected in hair up to 4 months after a single dose.11 Ketamine and its metabolites were also detected in scalp samples collected by a wet cotton swab up to 48 hours after administration of the drug. In a study of urine samples collected from hospitalized children who had received ketamine as an anesthetic, ketamine could be detected in the urine up to 11 days after drug administration and its metabolites could be detected for up to 14 days.12
Prolonged abuse of ketamine may result in psychological dependence. Chronic users will experience cravings when not taking the drug, making it hard to quit because the body is not used to functioning without it. Withdrawal symptoms can last for 4-6 days and can include:13
- Cravings for ketamine
- Loss of appetite
- Irregular and rapid heartbeat
If you currently use ketamine and find it difficult to quit, know that help and support are available. Please contact a professional rehab facility to discuss your treatment options with an addiction specialist. If you abruptly stop ketamine use you may experience intense cravings and discomfort, so it may be recommended to undergo medically supervised detox where any withdrawal symptoms can be properly managed.
- BinKharfi, M., & AlSagre, A. (2019). BET 2: Safety and efficacy of low-dose ketamine versus opioids for acute pain management in the ED. Emergency Medicine Journal, 36(2), 128-129.
- Brinck, E.C., Tiippana, E., Heesen, M., Bell, R.F., Straube, S., Moore, R.A., & Kontinen, V. (2018). Perioperative intravenous ketamine for acute postoperative pain in adults. The Cochrane Database of Systemic Reviews, 12(CD012033).
- Bell, R.F., & Kalso, E.A. (2018). Ketamine for pain management. PAIN Reports, 3(5), e674.
- Duman, R.S. (2018). The Dazzling Promise of Ketamine. Cerebrum, Volume 2018(Mar-Apr 2018), cer-04-18.
- Dadiomov, D., & Lee, K. (2019). The effects of ketamine on suicidality across various formulations and study settings. The Mental Health Clinician, 9(1), 48-60.
- Drug Enforcement Administration. (2017). Ketamine. Drugs of Abuse: A DEA Resource Guide.
- Rosenbaum, S.B., & Palacios, J.L. (2019). Ketamine. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing.
- U.S. Food and Drug Administration. (2019). FDA approves new nasal spray medication for treatment-resistant depression; available only at a certified doctor’s office or clinic.
- PubChem. (2019). Ketamine.
- Par Pharmaceutical. (2017). Ketalar (ketamine hydrochloride) injection.
- Xiang, P., Sun, Q., Shen, B., & Shen, M. (2011). Disposition of ketamine and norketamine in hair after a single dose. International Journal of Legal Medicine, 125(6), 831-840.
- Adamowicz, P., & Kala, M. (2005). Urinary excretion rates of ketamine and norketamine following therapeutic ketamine administration: method and detection window considerations. Journal of Analytical Toxicology, 29(5), 376-382.)
- Morgan, C.J., & Curran, H.V. (2012). Ketamine use: a review. Addiction, 107(1), 27-38.