In an emergency: if someone can’t be woken or is struggling to breathe, call 911. If opioids could be involved, give naloxone (Narcan) if available. Naloxone does not reverse ketamine, but it can reverse an accompanying opioid overdose and will not harm someone if opioids are absent. Do not wait to see whether it works before calling 911.[1,2] Lay the person on their side and stay with them until help arrives.[1]
Can you overdose on ketamine? Yes. The Drug Enforcement Administration warns that a ketamine overdose “can cause unconsciousness and dangerously slowed breathing.”[3] In the United States, most deaths involving ketamine also involve other drugs, especially fentanyl.[4]
What Are the Signs of an Overdose?
Call 911 if someone who has taken ketamine shows any of these:[1,3]
- They are unconscious or can’t be woken up.
- Their breathing is slow, shallow or labored, or they make choking sounds.
- Their lips or nails turn blue or gray.
Ketamine can also make people feel disconnected and not in control,[3] so they can get hurt without realizing it.
How Often Is Ketamine the Only Drug Involved?
In the CDC dataset, ketamine was rarely the only drug involved. The CDC reviewed about 229,000 overdose deaths in 45 states and jurisdictions from mid-2019 to mid-2023:[4]
- Ketamine was found in 912 deaths.
- It was classified as involved in 440.
- It was the only drug involved in just 24.
In most deaths where ketamine was found, other drugs were involved too: illegally made fentanyl in 59%, methamphetamine in 29% and cocaine in 27%. Deaths with ketamine detected also rose over the period.[4]
These records show that fatal overdoses in which ketamine appears usually involve multiple substances. They cannot tell us whether those substances were knowingly combined, and ketamine alone can still cause a fatal emergency. The CDC found ketamine in fewer than 1% of recorded overdose deaths, but testing was inconsistent and the data covered only participating jurisdictions, so it may have been underdetected.[4]
Is a Clinic Dose Different?
Yes. In clinical treatment, the product and dose are known, patients are screened beforehand, other medications can be reviewed, and staff monitor them afterward. Spravato—the FDA-approved esketamine nasal spray—must be administered in a certified healthcare setting, with monitoring for at least two hours. Its label lists slowed breathing among its serious risks.[5] Street ketamine comes with no monitoring and no guarantee of strength or purity. For more on treatment, see our guide to ketamine for depression.
Is Bladder Damage a Sign of Overdose?
No. It is a separate harm that builds up over time. Overdose is a sudden emergency; bladder damage comes from regular, long-term use.
- Regular users can develop severe urinary symptoms and pelvic pain.
- Some develop ulcerative cystitis, and long-term users can develop kidney problems.
- Stopping ketamine is the first step in treatment. Early damage can respond to care; severe cases may need surgery.[6]
Frequent, urgent or painful urination in someone who uses ketamine is a reason to see a doctor.
Where Can You Get Help?
- Emergency: call 911.
- Questions about a possible poisoning: call Poison Help at 1-800-222-1222. The call is free and private, and connects you to a nurse, pharmacist or doctor at your local poison center.[7]
- Legal worries: most states have laws that may protect a person who is overdosing from criminal penalties.[1]
To learn what ketamine feels like and why experiences vary, read what does ketamine feel like. For a researcher’s view of ketamine as a treatment, see our conversation with Dr. Roger McIntyre.
References
- Centers for Disease Control and Prevention. What to do if you think someone is overdosing.
- Centers for Disease Control and Prevention. 5 things to know about naloxone.
- Drug Enforcement Administration. Ketamine: drug fact sheet.
- Vivolo-Kantor AM, Mattson CL, Zlotorzynska M. Notes from the field: ketamine detection and involvement in drug overdose deaths — United States, July 2019–June 2023. MMWR Morb Mortal Wkly Rep. 2024;73:1010–1012.
- US Food and Drug Administration. Spravato (esketamine) nasal spray: prescribing information and Medication Guide. Revised September 2026.
- Castellani D, Pirola GM, Gubbiotti M, Rubilotta E, Gudaru K, Gregori A, Dellabella M. What urologists need to know about ketamine-induced uropathy: a systematic review. Neurourology and Urodynamics. 2020;39(4):1049–1062.
- Health Resources and Services Administration. The Poison Help line.
Editor’s note: This article was originally published on December 23, 2022, by Robert Hammell. In October 2026 the editors rewrote it to put emergency guidance first, use U.S. data, separate overdose from long-term bladder damage, and rest every claim on sources we could verify. This article is for information only and is not medical advice.
Reviewd by Chana Frenkel, PhD.
Last updated October 2026 · Originally published December 23, 2022.
