Ketamine shows promising results for anxiety, though it is not yet approved specifically for anxiety disorders. Most of the strong clinical evidence centers on depression, but ketamine’s rapid-acting effects on mood and emotional distress have led a growing number of clinicians to use it off-label for anxiety, particularly when standard treatments have failed. Relief can begin within hours of a single session, a dramatic contrast to traditional medications that often take weeks to build up.
What the Evidence Shows for Anxiety
Most large-scale ketamine research has focused on depression rather than anxiety specifically. IV ketamine produces a large, statistically significant reduction in depressive symptoms, and because depression and anxiety frequently overlap, many patients in those studies reported improvements in anxiety as well. Smaller studies and clinical observations suggest ketamine can reduce generalized anxiety, social anxiety, and the anxious component of PTSD, but the evidence base is thinner than it is for depression.
The practical takeaway: if your anxiety exists alongside depression or hasn’t responded to first-line treatments like SSRIs and therapy, ketamine may offer meaningful relief. If you have a standalone anxiety disorder with no depressive features, the supporting research is more limited, and a provider will likely weigh your options more carefully before recommending it.
How Quickly It Works
Speed is ketamine’s most distinctive advantage. Traditional anti-anxiety medications and antidepressants can take four to six weeks before you notice a difference. Ketamine can produce noticeable improvement in mood and anxiety within hours, sometimes even minutes, after a session. For people in acute distress, that rapid onset can be genuinely life-changing.
The flip side is that the effects of a single session don’t last indefinitely. How long relief persists varies widely from person to person, and researchers still don’t have a firm consensus on the typical duration. Most clinics structure treatment as an initial series of sessions over two to three weeks, followed by maintenance visits to sustain the benefits.
Maintenance and Ongoing Treatment
Ketamine is not a one-and-done treatment for most people. After an initial loading phase (commonly six sessions over two to three weeks for IV ketamine), many patients need periodic booster sessions to keep symptoms at bay. The frequency varies considerably. Some people return once or twice a month, while others find their symptoms remain manageable with far less frequent visits. Your provider will adjust the schedule based on how long your relief lasts between sessions.
This ongoing commitment is worth factoring into your decision. Each IV session typically costs several hundred dollars, and most insurance plans do not cover off-label ketamine infusions. The FDA-approved nasal spray, esketamine (brand name Spravato), is more likely to be covered by insurance, but it is only approved for treatment-resistant depression and depression with acute suicidal thoughts, not for anxiety on its own.
IV Ketamine vs. Nasal Spray Esketamine
Ketamine is delivered in several ways, and the route matters. The two most common clinical options are intravenous (IV) racemic ketamine and intranasal esketamine.
IV ketamine, administered as a slow drip over about 40 minutes, has the stronger effect in head-to-head comparisons. Meta-analyses show it produces a large reduction in symptoms, with meaningful responses at doses as low as 0.2 mg/kg. The standard dose is 0.5 mg/kg, and going higher than that does not appear to increase the benefit.
Intranasal esketamine also works, but its effect size in clinical trials is smaller. Doses of 56 to 84 mg, administered twice weekly, show the best results. A 28 mg dose does not reliably outperform placebo. Esketamine is roughly four times more potent at the brain receptors ketamine targets, but the nasal spray delivers a lower overall dose to the bloodstream than an IV drip, which likely explains the difference in outcomes.
Other routes exist, including subcutaneous injections, intramuscular injections, and oral lozenges. These are less studied but are sometimes used when IV access isn’t practical or when at-home treatment is preferred. Oral ketamine has the lowest bioavailability, meaning less of the drug reaches your brain, and the evidence supporting it is the weakest of the available options.
Side Effects During and After Sessions
Ketamine is a dissociative anesthetic, so the most common experience during a session is a feeling of disconnection from your body or surroundings. This can range from mild floating sensations to more intense perceptual distortions. For most people, this dissociation resolves within an hour or two after the infusion ends. Other common short-term effects include nausea, dizziness, increased blood pressure, and a temporary feeling of grogginess.
These acute side effects are the reason IV ketamine is administered in a clinical setting where your vitals can be monitored. You won’t be able to drive yourself home afterward, so plan for someone to pick you up or arrange a ride.
Long-term risks are more relevant for people using ketamine frequently or at high doses over extended periods. Chronic, heavy use has been associated with severe bladder inflammation, causing symptoms like frequent urination, urgency, bladder pain, and blood in the urine. This complication is well-documented in people who abuse ketamine recreationally at far higher doses than clinical protocols use, but it’s still something to be aware of if you’re receiving ongoing maintenance treatments. Your provider should ask about urinary symptoms at follow-up visits.
Who Should Avoid Ketamine
Ketamine is not appropriate for everyone. People with a history of psychosis or schizophrenia are generally considered poor candidates, as ketamine can worsen psychotic symptoms. The American College of Emergency Physicians lists psychiatric illness as a contraindication for dissociative sedation with ketamine, and most ketamine clinics screen carefully for psychotic disorders before starting treatment.
High blood pressure and a fast heart rate were historically listed as contraindications, though more recent evidence has softened that position. Ketamine does temporarily raise blood pressure during a session, so if you have uncontrolled hypertension, your provider will want to address that first. A history of substance use disorder also warrants a careful conversation, since ketamine has some potential for misuse.
If you’re currently taking certain medications, particularly benzodiazepines at high doses, they may blunt ketamine’s effectiveness. A provider experienced in ketamine therapy will review your full medication list before recommending treatment.
What a Typical Treatment Experience Looks Like
For IV ketamine, you’ll sit or recline in a treatment room, usually with dim lighting and sometimes with music or an eye mask. A nurse or clinician starts a small IV line, and the infusion runs for roughly 40 minutes. During that time, you may feel relaxed, spacey, or mildly disoriented. Some people describe visual or emotional experiences they later find meaningful, while others simply feel drowsy. After the drip finishes, you’ll rest for another 30 to 60 minutes until the acute effects wear off, then head home with your designated driver.
For intranasal esketamine (Spravato), sessions happen in a certified healthcare setting. You self-administer the nasal spray under supervision, then stay for at least two hours of monitoring. These sessions are typically scheduled twice a week for the first month, then weekly or biweekly depending on your response.
Many clinics recommend pairing ketamine sessions with psychotherapy, either during or shortly after the infusion, when your brain may be more receptive to processing difficult emotions. This combination, sometimes called ketamine-assisted psychotherapy, is increasingly popular, though the evidence for whether it improves outcomes beyond ketamine alone is still developing.