How many ketamine sessions do people usually need

Most ketamine treatment for depression starts with an induction series of about six sessions over two to four weeks, and people who respond then move to maintenance sessions spaced out over weeks or months. Spravato has a fixed schedule written into its FDA label. Off-label IV and at-home ketamine do not, which is why the number you hear depends heavily on which clinic you ask.

Why the number varies so much

The FDA approved esketamine (Spravato) with a specific dosing schedule. Racemic ketamine, the form given by IV, injection or lozenge, has never been approved for depression, so there is no official schedule for it. Clinics build protocols from published trials, their own experience and, sometimes, their business model. That is why one clinic proposes six infusions and another proposes twelve.

Your own history matters too. How severe the depression is, how many treatments have failed, whether there is significant anxiety or PTSD alongside it, and how quickly you respond all shape the plan. A good clinician will explain the schedule they suggest and what would make them change it.

What the Spravato label says

For treatment-resistant depression, the Spravato prescribing information describes three phases:

• Induction, weeks 1 to 4: two sessions a week. The first dose is 56 mg, with later doses at 56 mg or 84 mg depending on response and tolerability.
• Weeks 5 to 8: one session a week.
• Week 9 onward: one session a week or every two weeks, using the least frequent schedule that keeps the response going.

That works out to 12 sessions in the first two months, then ongoing maintenance. The label also says to reassess periodically whether continued treatment is needed. Every session takes place in a certified healthcare setting with at least two hours of observation afterward under the Spravato REMS program.

For the separate indication of depressive symptoms in adults with major depressive disorder and acute suicidal thoughts or behavior, the label describes twice-weekly dosing for four weeks alongside other treatment, after which the need for continued use is reassessed.

What the IV ketamine research used

The early studies that made ketamine famous in depression tested a single infusion. They showed a fast effect that often faded within a week or two. Researchers then tested repeated infusions to see whether the benefit could be extended.

Several open-label studies gave six infusions over about two weeks. A randomized trial published in the American Journal of Psychiatry in 2016 compared twice-weekly and three-times-weekly infusions over four weeks and found the two schedules performed similarly, which is one reason many clinics settled on twice weekly. In 2023, a large trial in the New England Journal of Medicine compared ketamine with ECT in people with treatment-resistant depression without psychosis, using twice-weekly infusions over three weeks, and found ketamine was not inferior to ECT on its main outcome.

The dose used in most of this research is 0.5 mg/kg over 40 minutes, the figure the 2017 consensus statement from the American Psychiatric Association's research council described as the most commonly studied. That same statement noted there was not enough evidence to settle questions about the ideal frequency or how long to continue.

How response is judged

Clinicians usually track symptoms with a standard questionnaire before each session, such as the PHQ-9, so that changes can be measured rather than guessed at. By the end of an induction series, it is generally clear whether there has been a meaningful response, a partial one, or very little.

If there has been no response after an adequate series, most clinicians would not simply add more sessions. They would look again at the diagnosis, at other conditions such as sleep problems or substance use, and at other treatments. Our post on what treatment-resistant depression actually means covers the options that sit alongside ketamine.

Maintenance: the part with the least evidence

The antidepressant effect of ketamine commonly fades over days to weeks after the induction series ends. Many people who respond move to maintenance sessions, often starting every one to four weeks and stretching the gap over time if they stay well.

There is far less research on this phase than on induction. We do not have a validated way to decide how often maintenance should happen, when to stop, or what years of repeated dosing does to the body. Heavy recreational ketamine use is linked to bladder damage and memory problems, which is a reason to take long-term exposure seriously even at much lower medical doses.

What helps the effect last

The honest answer is that research is still sorting this out. Ketamine is generally used alongside an oral antidepressant, psychotherapy and ongoing psychiatric care. Some programs add integration sessions with a therapist after dosing. The working idea is that ketamine may open a window in which other treatment works better, though that has not been proven to the standard of the core efficacy findings.

Practical steps that support any depression treatment still apply: steady sleep, limiting alcohol, staying connected to people and keeping up with whatever else is in your treatment plan.

Questions to ask about a proposed schedule

How many sessions are in the induction series, and why that number? How will you measure whether it is working? What happens if I have not responded by the end? What does maintenance usually look like at your clinic, and how do you decide when to space it out or stop? Clear answers to those questions say more about a clinic than any single number.

Our pillar guide on ketamine for treatment-resistant depression explains where this treatment fits and who is screened out. Ketamine is not a first-line treatment, and an evaluation is the step that decides whether it is reasonable for you at all. Our ketamine therapy page explains how Aone builds and reviews treatment plans.

Questions patients ask us

Why do clinics often recommend six ketamine infusions?

Because six infusions over about two weeks is what several influential studies tested. It became a practical default. It is not proven to be the right number for everyone. Some people respond after fewer sessions, some only toward the end of a series, and some not at all. Ask why a clinic proposes its number.

How many Spravato sessions are in the first two months?

Under the label for treatment-resistant depression, there are two sessions a week for weeks 1 to 4 and one a week for weeks 5 to 8, which comes to 12 sessions. From week 9, sessions continue weekly or every two weeks for people who respond, with periodic reassessment of whether treatment is still needed.

Is twice-weekly ketamine better than three times a week?

A randomized trial published in 2016 compared twice-weekly and three-times-weekly IV ketamine over four weeks and found similar results. That is one reason many clinics use twice weekly. The trial was not large, so it does not settle the question, but it suggests more frequent dosing is not clearly better.

How do I know if ketamine is working?

Clinicians usually track symptoms with a standard questionnaire such as the PHQ-9 before each session. Improvement may show as lighter mood, more energy, better sleep or negative thoughts losing their grip. By the end of an induction series it is usually clear whether there is a meaningful response, a partial one or very little.

What if I do not respond after the first series?

Adding more of the same is usually not the answer. A good clinician will review the diagnosis, check for conditions that mimic treatment-resistant depression, such as bipolar disorder, sleep apnea, thyroid problems or substance use, and discuss other treatments. Not responding to ketamine is common and does not mean nothing else will help.

How often are ketamine maintenance sessions?

There is no standard schedule for off-label ketamine. Many clinics start maintenance every one to four weeks and stretch the gap if you stay well. Spravato's label allows weekly or every-two-week dosing after week 8. The goal should be the least frequent schedule that keeps the response, reviewed regularly.

Can I stop ketamine maintenance at some point?

Some people do, particularly when other treatment such as therapy and medication is working well. There is limited research on how and when to stop. A reasonable approach is gradually spacing sessions further apart while monitoring symptoms, with a clear plan for what to do if depression returns. Decide this with your clinician.

Does a higher dose mean fewer sessions?

Not necessarily. Most IV research used 0.5 mg/kg over 40 minutes, the dose the 2017 APA research council consensus statement described as most commonly studied. Spravato uses 56 mg or 84 mg. Higher doses raise the risk of side effects and are not clearly more effective. Dose and frequency are clinical decisions made together.

Is long-term repeated ketamine safe?

It is not well studied. Heavy recreational ketamine use is linked to bladder damage, memory problems and dependence. Medical doses are lower and supervised, but years of repeated dosing have limited research. That uncertainty is a reason to review maintenance regularly, watch for warning signs and avoid open-ended plans without a review point.

Do I still need therapy and other treatment during ketamine sessions?

Generally yes. Ketamine is usually used alongside an oral antidepressant, psychotherapy and ongoing psychiatric care, though Spravato is now also approved as a standalone treatment for treatment-resistant depression. Many clinicians think ketamine may make other treatment easier to engage with, though that idea has not been proven as firmly as its short-term effect.