Ketamine: Uses, Risks, Spravato, and FDA Warnings

Ketamine is an anesthetic used in hospitals, operating rooms, and emergency care to put patients into a dissociated, pain-free state. In the United States its FDA-approved use is exactly that: induction and maintenance of general anesthesia, given by injection into a vein or muscle. It is not FDA-approved for any psychiatric condition. A closely related drug, esketamine (Spravato), is approved as a nasal spray for treatment-resistant depression, but the ketamine used in clinics, telehealth programs, and compounded products for depression is a different story, and the FDA has warned about it.

This guide covers what ketamine is, how it works, what it is approved for, how it differs from esketamine, what the label warns about, what the FDA says about ketamine for mental health, and what people misuse it for. It also covers the brand name Ketarol, which is another name for ketamine injection.

This is general information based on FDA labeling and FDA safety communications, not medical advice. Ketamine is a controlled substance. It should only be given by trained clinicians in a monitored setting.

Ketamine at a glance

Drug class	Dissociative general anesthetic; NMDA receptor antagonist
US brand name	Ketalar (other brands exist in other countries, including Ketarol)
FDA-approved use	Induction and maintenance of general anesthesia
Given by	Intravenous (IV) or intramuscular (IM) injection
Controlled substance	Schedule III in the United States
Most common adverse reactions	Emergence reactions (vivid dreams, hallucinations, delirium) and higher blood pressure and pulse
Not approved for	Depression, anxiety, PTSD, or any other psychiatric disorder

What ketamine is

Ketamine has been used in medicine since 1970, when it first gained US approval. It produces what doctors call dissociative anesthesia: the patient is detached from their surroundings and does not feel pain, while often keeping more of their own breathing and airway reflexes than with many other anesthetics. That profile made it especially useful in emergencies, in field and battlefield medicine, in children’s procedures, and where equipment or monitoring is limited.

Chemically, ketamine is a mixture of two mirror-image molecules, S-ketamine (esketamine) and R-ketamine (arketamine). That detail matters because the two products people hear about, ketamine and Spravato, are not the same drug: Spravato contains only the esketamine form.

How ketamine works

Ketamine blocks a receptor in the brain called the NMDA receptor, which responds to the messenger chemical glutamate. Blocking it changes how signals travel through brain regions involved in pain, awareness, and perception, which is why people feel disconnected from their body and surroundings.

In the past two decades, researchers noticed something else. A single low dose of ketamine, well below the anesthetic dose, can produce rapid antidepressant effects in some people, sometimes within hours, which is far faster than standard antidepressants. Scientists are still working out why. A 2018 review of the science describes several competing hypotheses, including effects on specific NMDA receptor subtypes, on the inhibitory nerve cells that control brain circuits, on a brain region called the lateral habenula, and on another glutamate receptor called AMPA, as well as roles for ketamine’s breakdown products. The same review notes that ketamine’s widespread use is limited by its abuse potential and its dissociative effects, which is why researchers are trying to develop drugs that keep the antidepressant action without those drawbacks.

What ketamine is approved for

Anesthesia (ketamine, Ketalar)

The FDA-approved use for ketamine hydrochloride is the induction and maintenance of general anesthesia, given by IV or IM injection. It is used alone for short procedures or combined with other anesthetics for longer ones.

Doses are set by the anesthesia team based on the patient’s weight, the route, and the purpose. As one example from the label, the starting IV dose to induce anesthesia is 1 to 4.5 mg per kg, given slowly over about 60 seconds. This is a hospital drug: it is not something to be dosed from an article.

Depression (esketamine, Spravato)

Spravato (esketamine) nasal spray was approved by the FDA in March 2019, together with an oral antidepressant, for treatment-resistant depression in adults. Its approval was later expanded to include depressive symptoms in adults with major depressive disorder who have acute suicidal ideation or behavior, and in January 2025 the FDA cleared it for use as a standalone treatment for major depressive disorder. Because of its risks, Spravato has a boxed warning covering sedation, dissociation, abuse and misuse, and suicidal thoughts and behaviors. Patients must be monitored for at least two hours after each dose, and it is available only through a restricted safety program called a REMS. The label states that Spravato is not approved as an anesthetic.

What ketamine is NOT approved for

This is the part many patients do not hear clearly.

The FDA has stated plainly that ketamine is not approved for the treatment of any psychiatric disorder. Ketamine clinics, telehealth companies, and compounding pharmacies offer IV, intramuscular, oral, and nasal ketamine for depression, anxiety, and PTSD. Prescribing ketamine for these uses is off-label, meaning a doctor is using an approved drug for a purpose the FDA has not approved. Doctors are legally allowed to do this, but it means the FDA has not judged the benefit and risk for those uses.

Compounded ketamine adds another layer. In warnings issued in 2022 and October 2023, the FDA noted that compounded drugs are not FDA-approved, so the agency has not evaluated their safety, effectiveness, or quality before marketing, and compounded ketamine has no approved indications or routes of administration. The FDA listed the known safety concerns with ketamine products, including abuse and misuse, psychiatric events, increases in blood pressure, respiratory depression (slowed breathing), and lower urinary tract and bladder symptoms. The agency added that, for FDA-approved ketamine used at appropriate doses for approved indications, the expected benefit outweighs these risks. It did not say the same for unsupervised use for psychiatric conditions.

If you are considering ketamine for depression, ask whether the treatment is Spravato (approved, with a safety program) or ketamine (off-label), who will monitor you, how blood pressure and breathing will be watched, what the plan is when treatment ends, and how much the treatment will cost. Avoid at-home ketamine programs that do not include in-person monitoring, and be wary of any provider who promises quick, guaranteed results.

Warnings on the ketamine label

The Ketalar prescribing information highlights these key risks:

Hemodynamic instability. Blood pressure, heart rate, and cardiac output frequently rise. Vital signs and cardiac function need monitoring during administration. The label lists a contraindication in patients for whom a significant rise in blood pressure would be a serious hazard.
Emergence reactions. Confusional states, vivid dreams, hallucinations, or delirium can occur while waking from anesthesia. The label advises reducing these by minimizing verbal, tactile, and visual stimulation of the patient during recovery.
Respiratory depression. Can occur with overdosage or too rapid an injection. Oxygen and ventilation must be maintained.
Pediatric neurotoxicity. Long-term cognitive deficits may occur when ketamine is used for longer than 3 hours in children 3 years old or younger.
Liver injury. The FDA lists drug-induced liver injury among its warnings for ketamine.
Hypersensitivity. Contraindicated in people with known hypersensitivity to ketamine or any of its ingredients.

The label’s drug interaction section says theophylline and aminophylline should not be co-administered with ketamine.

The two most common adverse reactions overall are emergence reactions and elevated blood pressure and pulse.

Bladder and urinary problems

One of the less obvious harms of ketamine, especially with repeated use, is damage to the urinary tract. The FDA’s warnings list lower urinary tract and bladder symptoms among the safety concerns. Symptoms include burning or pain with urination, frequent or urgent urination, blood in the urine, and pelvic pain. In heavy long-term users these problems can become severe. Anyone using ketamine repeatedly, whether under treatment or otherwise, who develops these symptoms should tell their clinician.

Misuse and dependence

Because ketamine causes dissociation and distorted perception, it is used recreationally, and it is a controlled substance (Schedule III). Repeated use can lead to tolerance and psychological dependence, and the urinary, psychiatric, and cognitive effects described above. Using it in unsupervised settings is riskier because impaired coordination and awareness make injuries, accidents, and unsafe situations more likely, and because street ketamine can be impure or mixed with other drugs.

If you or someone you know is struggling with drug use, a doctor or the free SAMHSA National Helpline (1-800-662-4357 in the United States) can point you to confidential help.

Ketamine and Ketarol: is there a difference?

Ketalar is the US brand. In other countries ketamine injection is sold under different names, and Ketarol is one of them. The active ingredient is ketamine hydrochloride. Whether a specific product is legal or available in your country depends on local regulations, and it should only be used under medical supervision. Buying ketamine products online or from unverified sources is risky because quality is not assured.

Who should be cautious

Ketamine requires particular caution or is not appropriate for people with:

Conditions where a rise in blood pressure or heart rate would be dangerous, such as uncontrolled high blood pressure or certain heart conditions
A history of psychosis or certain psychiatric conditions, since dissociation and hallucinations can be distressing or worsen symptoms
A history of substance use disorder
Liver disease
Bladder or urinary problems
Pregnancy, unless a clinician determines the benefits outweigh the risks
Young children, especially with prolonged exposure

These are general considerations. The anesthesia team or prescribing clinician makes the decision for each person.

What receiving ketamine for anesthesia is like

If ketamine is used for a procedure, the anesthesia team decides the route and dose after reviewing your history. Before, they will ask about heart and blood pressure problems, psychiatric history, liver or bladder problems, substance use, pregnancy, and every medicine you take, since some interact. You will usually be told not to eat or drink for a set time before the procedure.

During anesthesia, monitors track heart rate, blood pressure, oxygen, and breathing, and the team keeps the airway secure. Ketamine can leave the eyes open and cause muscle movements, which is normal and does not mean the patient is aware or in pain.

Afterwards, emergence reactions are the main thing to expect. Some patients wake with vivid dreams, a floaty or detached feeling, confusion, or fear. These usually pass, and staff help by keeping the room calm and limiting noise, touch, and bright light, as the label suggests. Nausea and vomiting can occur. You will need someone to accompany you home after most outpatient procedures, and you should not drive or make important decisions until the team says the effects have worn off.

How ketamine compares with other anesthetics

Ketamine is not always the first choice. Its distinguishing features are what make it useful in some cases and unsuitable in others.

It tends to support blood pressure and heart rate, whereas many anesthetics lower them. That can help a patient who is in shock or has low blood pressure, and it can be a problem for a patient with severe high blood pressure or certain heart conditions.
It preserves breathing and airway reflexes better than many alternatives, as long as it is not given too fast or in too high a dose. The label still warns about respiratory depression and requires oxygen and ventilation to be available.
It provides strong pain relief along with sedation, while many other anesthetics need a separate pain medicine.
It causes emergence reactions, which are less common with drugs such as propofol. Anesthesia teams sometimes add a sedative to reduce them.
It works by IV or IM injection, which helps when no IV line is available, such as in children who are frightened of needles or in emergency settings.

The right agent for a patient depends on their health, the procedure, and the setting, which is why anesthesia teams choose it case by case.

Questions to ask before starting ketamine treatment for depression

If a clinic or telehealth service offers ketamine for depression, these questions help you judge whether the care is safe and appropriate.

Is this ketamine or Spravato (esketamine), and is it FDA-approved for what you are being treated for?
Who is prescribing it, what are their credentials, and will a physician see you in person?
Will you be monitored in the clinic during and after each dose, including blood pressure, and for how long?
Do you screen for heart disease, high blood pressure, psychosis, bipolar disorder, substance use, bladder problems, and pregnancy first?
Is the product FDA-approved or compounded, and where is it made?
What happens if you have a bad reaction, and how quickly can emergency care be reached?
What is the plan for the long term, how often are sessions needed, what does it cost, and does insurance cover it?
How will they handle your existing antidepressant and mental health care?
What would be the signs that you should stop?

Be cautious about any program that dispenses ketamine for home use without monitoring, that guarantees results, or that discourages you from talking to your regular doctor. If you are in crisis or thinking about suicide, call or text 988 in the United States, or your local emergency number.

Frequently asked questions

Is ketamine FDA-approved for depression?

No. Ketamine (Ketalar) is FDA-approved for general anesthesia only. The FDA has stated that ketamine is not approved for any psychiatric disorder. Esketamine (Spravato), a nasal spray, is approved for treatment-resistant depression and certain other depressive conditions.

What is the difference between ketamine and Spravato?

Ketamine is a mixture of two mirror-image molecules (R and S) approved as an anesthetic. Spravato contains only the S form, esketamine, and is approved as a nasal spray for depression, with a boxed warning and a REMS safety program.

Is compounded ketamine safe?

The FDA has warned that compounded ketamine is not FDA-approved, so its safety, effectiveness, and quality have not been evaluated by the agency. Known concerns include abuse and misuse, psychiatric events, higher blood pressure, slowed breathing, and bladder symptoms.

What are the side effects of ketamine?

The most common are emergence reactions (vivid dreams, hallucinations, confusion) and increases in blood pressure and heart rate. Other risks include respiratory depression, liver injury, and urinary tract and bladder problems with repeated use.

Is ketamine addictive?

It has abuse potential and is a Schedule III controlled substance. Repeated use can lead to tolerance and psychological dependence.

How long does ketamine anesthesia last?

Duration depends on the dose, the route, and whether other drugs are given. The anesthesia team controls this, and recovery can include emergence reactions, which are reduced by keeping the environment calm and quiet.

Can children receive ketamine?

Ketamine is used in pediatric anesthesia and procedures. The label warns that long exposure, more than 3 hours, in children 3 years old or younger may cause long-term cognitive problems, so its use in very young children is carefully weighed.

What is Ketarol?

Ketarol is a brand name for ketamine injection sold in some countries. It contains the same active ingredient as ketamine products elsewhere and carries the same class of risks.