Medically Reviewed

How Long Does Ketamine Stay in Your System?

2 min read · 4 sections

Ketamine Uses & Effect Duration

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.

Ketamine Half-Life

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

How Long is Ketamine in Your System?

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 Factors such as age, body mass, metabolic rate, drug dosage, and route of administration can affect the duration and elimination of the drug.

Body System Time in System
Blood Up to 72 hours
Hair Up to a month or more
Saliva Up to 24 hours
Urine Up to 14 days

Ketamine Abuse Treatment Options

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. Ketamine withdrawal symptoms can last for 4-6 days and can include:13

  • Cravings for ketamine
  • Loss of appetite
  • Tiredness
  • Chills
  • Sweating
  • Restlessness
  • Tremors
  • Anxiety
  • Depression
  • 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.


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