Ketamine Side Effects: Physical, Mental & Long-Term Effects

What is Ketamine?

Ketamine hydrochloride, also commonly referred to as ketamine, is a short-acting general anesthetic that is injected into patients to produce loss of consciousness before and during surgery or other medical procedures. Ketamine can be found as a white powder or clear liquid.

The off-label use of ketamine has also been utilized for the successful treatment of chronic and acute pain, procedural sedation, and alcohol withdrawal management.6-8 A nasal spray form of the drug, called esketamine, has been recently approved by the Food and Drug Administration for the treatment of major depression.9

Ketamine is a dissociative drug that distorts perceptions of sight and sound, produces hallucinations, and provides the user with feelings of detachment from both the environment and self.

Due to these effects, the recreational use of ketamine has gained popularity among teens and young adults as a “club drug” that is used at dance clubs and raves. According to the U.S. Drug Enforcement Administration, the liquid drug is usually injected or mixed in drinks, or it is heated and provided as a powder that can be snorted or smoked.10

Ketamine Side Effects

When properly administered by a doctor, a therapeutic dose of ketamine will leave a patient feeling calm and relaxed. During their state of sedation patients will also experience immobility, amnesia, and relief from pain.

The recreational misuse of ketamine can be physically hazardous and poses many dangers to the user, especially at higher doses.1 Individuals who take a high enough dose of ketamine are at risk of entering a “K-hole,” an unpleasant experience characterized by intense visual and auditory hallucinations coupled with a frightening detachment from reality.2

The onset of ketamine effects depends on how the drug is administered. If the drug is smoked, it takes effects immediately. Snorting produces effects in 5-10 minutes, and oral administration will produce effects in 15-20 minutes. The effects will last 30-45 minutes after injection, 45-60 minutes after snorting, and 1-2 hours after oral ingestion. Because ketamine is a relatively short-lasting drug, some people use in a binge cycle, in which they repeatedly use the drug to get high and re-administer the drug when they begin to crash.

The most common adverse side effects of ketamine use include:3

Mental Side Effects

  • Sedation
  • A dream-like state
  • Colorful dreams
  • Feelings of intense strength and power
  • Decreased focus
  • Agitation
  • Anxiety
  • Dizziness
  • Hallucinations
  • Difficulty thinking
  • Out of body experiences
  • Alterations in discernment
  • Amnesia
  • Confusion
  • Reduced awareness of environment
  • Disorientation
  • Drowsiness
  • Dissociation
  • Decreased ability to feel pain
  • Forgetfulness
  • Decreased coordination

Physical Side Effects

  • Double vision
  • Involuntary eye movements
  • Seizures
  • Impaired motor function
  • Nausea
  • Vomiting
  • Slowed breathing
  • Cessation of breathing
  • Elevated blood pressure
  • Decreased heart rate
  • Tachycardia
  • Irregular heartbeat
  • Motionlessness
  • Excessive salvia production
  • Garbled speech

Some people may also experience nervousness, chest pain, tremors, worry, flashbacks, disorientation, psychosis, lightheadedness, vomiting, nausea, seizures, and paranoia.

Long-Term Effects of Ketamine Use

Frequent, repeated abuse of ketamine can cause damage to various major organs, including the digestive tract, urinary tract, and brain. Drug abuse also strains the liver and kidneys, and it can lead to permanent damage to these systems. According to a study published by the journal Addiction, some of the major physical harms caused by ketamine are ulcerative cystitis and memory deficits.

Long-term side effects may include impaired memory, mood swings, respiratory distress, bladder and urination issues, rapid heart rate, seizures, overdose, and more.

The most serious long-term effect of repeated, high-dose ketamine abuse is a physical tolerance to, and dependence on, the drug. Tolerance means that the person will need to take more of the substance to feel the original effects, and in the case of ketamine, that may lead to very harmful practices to get a more intense high.

The chronic abuse of ketamine can result in psychological dependence, causing users to experience intense cravings when not taking the drug. Someone who becomes psychologically dependent on ketamine may go through withdrawal if use of the drug is suddenly stopped. This can result in anxiety, depression, insomnia, and flashbacks.4

People who take ketamine typically ingest the drug orally or nasally; however, it can also be injected, either intravenously or intramuscularly, which increases the risk of damage to veins, muscles, skin, and internal organs. Injectable drugs are more likely to cause skin infections, transmit HIV or hepatitis through needle-sharing, or lead to endocarditis, an infection of the heart valves.

Other long-term effects associated with ketamine use include memory impairments, bladder and kidney problems, and depression.5

Long-Term Mental Issues

Many intoxicating substances lead to cognitive decline, memory difficulty, and mood changes when they are abused for a long time, and ketamine is no exception. People who abuse this anesthetic have trouble with memory, issues with thinking clearly, and mood swings. Impairments in creating new memories, accessing old memories, verbal memory (e.g., forgetting words, names, and conversations), short-term memory, and visual memory continue while the person abuses ketamine. These are likely to improve when a person gets help overcoming ketamine addiction.

Long-term mental side effects specific to ketamine include:

  • Decreased sociability
  • Attention deficit or dysfunction
  • Impaired memory recall
  • Flashbacks

Hallucinogenic drugs are often associated with flashbacks even if they are used once; however, drugs like PCP, DXM, and ketamine can all cause flashbacks too. Also like these other drugs, ketamine can trigger psychosis or schizophrenia in those who are predisposed to these mental health disturbances.

Long-Term Physical Issues

Some people who abuse ketamine for a long time experience changes to vision, including anomalies, which are typically mild. These can make some tasks like driving more difficult.

Ketamine can cause more serious damage to organ systems, especially to the bladder, kidneys, and heart. People who take large doses of ketamine are likely to experience respiratory distress, rapid heart rate, and seizures. Chronic abuse of this drug specifically damages the bladder, leading to inflammation in that organ, incontinence, and permanent harm. Symptoms of ketamine-caused bladder damage include:

  • Painful urination
  • Trouble urinating
  • Frequent urge to urinate
  • Inability to hold urine
  • Cloudy or bloody urine

Ketamine is highly associated with developing ulcerative cystitis, a form of panful bladder syndrome characterized by damage to the bladder’s tissues leading to chronic, recurring pelvic pain, with ulcers – red, bleeding patches – in the walls of the bladder. According to the Interstitial Cystitis Association, about 5 percent of people with interstitial cystitis, whether it is ulcerative or not, develop end-stage cystitis. This condition is a failure of the bladder, leading to an organ that is hard, extremely painful, and unable to hold urine. About 10 percent of any cystitis case is ulcerative, and abusing ketamine increases the risk of developing this specific type of bladder condition. About 33 percent of people who abuse ketamine, according to one study, developed reduced bladder volume. Ulcerative cystitis generally results from chronic and frequent use of this drug. Ulcerative cystitis is the destruction of the lower urinary tract. While the symptoms of ulcerative cystitis can be treated, the damage may not be reversible. The most severe cases of cystitis result in bladder augmentation, in which damaged parts of the urinary tract are removed. The most effective treatment of ketamine-induced ulcerative cystitis is to completely cease all use of ketamine. Once the drug is no longer being used, symptoms relating to urinary tract damage may subside.

This dissociative drug can also cause kidney failure, heart complications, and trouble breathing. While acute effects like heart attack, seizures, stroke, or respiratory failure are more likely to occur during overdose, experiencing an overdose can also lead to damage to internal organs, including the brain.

Treatment Options

If you or someone you love is struggling to quit ketamine, please contact an addiction specialist at a professional rehab facility to discuss your treatment options. Abruptly quitting ketamine can cause intense cravings and discomfort, so it may be necessary to first undergo a medically supervised detox where any ketamine withdrawal symptoms can be properly managed.

Following detox, treatment programs will be personalized to address the length and severity of ketamine abuse as well as the presence of any co-occurring disorders. Treatment will often encompass various forms of individual therapy, group therapy, family therapy, and behavioral therapy.

Find Ketamine Rehab Near You


  1. Wood, D., Cottrell, A., Baker, S.C., Southgate, J., Harris, M., Fulford, S., …& Gillatt, D. (2011). Recreational ketamine: from pleasure to pain. BJU International,107(12), 1881-1884.
  2. Muetzelfeldt, L., Kamboj, S.K., Rees, H., Taylor, J., Morgan, C.J., & Curran, HV. (2008). Journey through the K-hole: phenomenological aspects of ketamine use. Drug and Alcohol Dependence, 95(3):219-229.
  3. Rosenbaum, S.B., & Palacios, J.L. (2019). Ketamine. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing.
  4. Lin, P.C., Lane, H.Y., & Lin, C.H. (2016). Spontaneous Remission of Ketamine Withdrawal-Related Depression. Clinical Neuropharmacology, 39(1), 51-52.
  5. Morgan, C.J., & Curran, H.V. (2012). Ketamine use: a review. Addiction, 107(1), 27-38.
  6. 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.
  7. Bell, R.F., & Kalso, E.A. (2018). Ketamine for pain management. PAIN Reports, 3(5), e674.
  8. Wieruszewski, P.M., Leung, J.G., & Nelson, S. (2018). Ketamine Use in the Intensive Care Unit. AACN Advanced Critical Care, 29(2), 101-106.
  9. Yale Medicine. (2019). How New Ketamine Drug Helps with Depression.
  10. Drugs of Abuse: A DEA Resource Guide. (2017). Ketamine.
Last Updated on September 14, 2022
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