Ketamine Safety and Side Effects
Most of what you will read about ketamine harm comes from chronic, high-dose, unsupervised use. That is a different exposure from six monitored 40-minute infusions. Both things are true at once, and this page tries to keep them straight rather than pick whichever is convenient.
Talk to a board-certified doctor about whether ketamine may be an appropriate option for you. The first consultation is free.
Typical course | 6 infusions over 2 to 3 weeks |
Blood pressure | Rises during the infusion, peaks around 40 minutes, back to baseline by about 4 hours |
Monitoring | Vitals every 15 minutes during, every 30 minutes for 2 hours after |
Recovery before you leave | Usually 30 to 60 minutes, judged on your vitals and mental state rather than a timer |
Driving | Not until the next day, after a full night's sleep |
Dissociation | Dissociation peaks around 40 to 60 minutes and settles within about 1 to 2 hours |
Legal status | Schedule III controlled substance. Use for mental health conditions is off-label. |
Getting home | A responsible adult must take you home. We cannot treat you without a plan for this. |
Ketamine is a Schedule III controlled substance, FDA-approved as an anesthetic. Using it for mental health conditions is off-label, and we say so as part of consent rather than in the small print. Treatment here is always individualized following a physician evaluation.
What Actually Happens, and How Often
Most clinic pages describe side effects without giving a single number. These come from a 2025 pooled analysis of 33 studies covering just over 5,000 patients.
During the infusion | Dizziness around 19 percent, nausea around 13 percent, blurred vision around 9 percent. Dissociation is expected at this dose. When it is formally rated rather than only recorded if mentioned, roughly half of patients experience it. |
The same day | Headache, tiredness and a hangover-like feeling are common and settle within hours. No driving until the next day, after a full night's sleep. A responsible adult has to take you home. |
Serious events | In the pooled data, serious adverse events were not significantly more common than in control groups. Around 30 percent of patients do see blood pressure above 180 over 100 or a heart rate above 110 at some point during an infusion, which is why it is monitored. |
One figure worth stating plainly rather than hiding: people stop treatment because of side effects around four times more often than in control groups. That works out at roughly one in thirteen. Most people tolerate it well, but a meaningful minority do not, and you should know that before you start. (Need attention)
At the dose used for mental health treatment, ketamine does not meaningfully affect breathing in otherwise healthy people. Blood levels reach roughly 70 to 200 nanograms per millilitre, against 2,000 to 3,000 for surgical anaesthesia. You stay awake and able to talk throughout.
- You have a condition where a significant rise in blood pressure would be dangerous, including a known aneurysm, aortic disease or a recent heart attack
- You are experiencing active psychosis or current manic symptoms
- You have severely uncontrolled hypertension
- You are pregnant or breastfeeding, or you have a known hypersensitivity to ketamine
- Controlled high blood pressure or stable cardiac disease, which may need optimising or cardiology clearance first
- Bipolar disorder with a history of mania, which needs mood stabilisation and psychiatric co-management
- A history of substance use disorder, particularly involving ketamine or other dissociatives
- Liver impairment, raised pressure in the eye, or a history of head injury or intracranial problems
- Taking an MAOI antidepressant, which calls for closer monitoring rather than exclusion
- Daily benzodiazepine use, which is worth reviewing before treatment
This list is not a substitute for screening. If ketamine does not appear appropriate following your evaluation, your doctor will discuss the reasons with you and talk through other options. (Need attention)
The Three Things People Worry About
If you have read something worrying about ketamine, it was probably about one of three things: your bladder, your memory, or getting hooked. All three are worth understanding properly. The short version is that all three are driven by how much and how often, and a monitored course of infusions sits at the very low end of both.
Bladder problems are well documented in heavy recreational use, where people take ketamine daily or near-daily at many times a treatment dose, and more than a quarter of them develop urinary symptoms. At treatment doses there is one published case so far. That is genuinely reassuring, though not the same as proof, because nobody has run long-term surveillance. It is why we ask about urinary symptoms at repeat visits, and why telling us early matters. Memory is a similar picture. Repeated clinical courses have consistently found no lasting effect and some found improvement, while lasting problems show up in chronic recreational users.
On getting hooked: ketamine does have abuse potential, which is why it is a controlled substance, and we are not going to tell you the risk is zero. In supervised treatment it is very low. A 2025 review across 16 studies and 2,174 patients found four cases. What keeps that number low is structural rather than lucky: no take-home supply, a limited number of infusions, toxicology screening, and treatment kept to the minimum needed to get a response. It is a fair thing to ask any clinic how they handle. (Need attention)
When Might You Notice Changes?
What our customers want to know
Will I lose control or hallucinate during an infusion?
You stay awake and able to talk. Most people describe a floaty, detached feeling and a distorted sense of time rather than hallucinations. It peaks around 40 to 60 minutes and settles within one to two hours. A clinician is with you, and the infusion can be slowed or stopped at any point.
Will ketamine damage my bladder?
Bladder damage is real, and it is documented in chronic heavy recreational use, where more than a quarter of users develop urinary symptoms. At therapeutic doses there is one published case to date. That is not the same as proof of safety, since nobody has run long-term surveillance, which is why we ask about urinary symptoms at repeat visits. Tell us early if anything changes, because stopping early prevents further damage.
Is ketamine addictive?
It has genuine abuse potential, which is why it is a controlled substance. Saying it is simply not addictive would be untrue. In supervised treatment the observed rate is low, roughly four cases of clear dependence across 2,174 patients in a 2025 review. The safeguards are what keep it low: no take-home supply, a limited course, and toxicology screening.
Can I drive myself home?
No. A responsible adult needs to take you home, and you should not drive or operate machinery until the following day, after a full night's sleep. This is not a formality, and we cannot treat you without a plan for getting home.
Is it safe if I have high blood pressure or a heart condition?
It depends which, and how well controlled. Ketamine reliably raises blood pressure during the infusion, so uncontrolled hypertension and unstable cardiac disease are exclusions until they are managed. Controlled hypertension and stable cardiac disease are often workable with clearance and monitoring. This is decided at evaluation, not on a website.
Will it affect my memory long term?
During and shortly after an infusion, thinking is temporarily affected and then clears. Across repeated clinical courses, studies have consistently found no lasting cognitive impairment, and some found improvement. Persistent memory problems are documented in chronic recreational users at far higher doses and frequencies.
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