Medically reviewed by Dr. Lisa Parker, DNP, APRN, NP | Owner & Clinical Director, Parker Neuroscience, Omaha, Nebraska

Here’s the honest answer up front: ketamine is a promising, but still emerging, option for obsessive-compulsive disorder that hasn’t responded to standard treatment. Early research shows it can reduce obsessive thoughts quickly for some people, but the evidence is much earlier stage than it is for depression, the effects of a single treatment tend to be short-lived, and it appears to work best alongside OCD-specific therapy rather than on its own. At Parker Neuroscience, IV ketamine may be considered for OCD after a full evaluation, used off-label, and never as a replacement for the therapy that remains the foundation of OCD care.

Why Standard OCD Treatment Doesn’t Work for Everyone

The first-line treatments for OCD are well established: serotonin-based medications, usually SSRIs, and a specialized form of therapy called exposure and response prevention, or ERP. Together, they help a great many people. But a substantial share don’t get enough relief from them. A 2026 systematic review estimates that roughly 40 to 60 percent of people with OCD fail to respond to standard serotonergic and behavioral treatments.

That’s a large group of people living with intrusive thoughts and compulsions that haven’t meaningfully let up, often after years of trying. It’s also why researchers have started looking beyond serotonin altogether.

How Ketamine Works Differently

Most OCD medications act on the serotonin system. Ketamine acts on a different one entirely: glutamate, the brain’s most abundant excitatory neurotransmitter. There’s growing evidence that glutamate signaling plays a role in the brain circuits involved in OCD, which is part of why a medication that works through this pathway has drawn research interest for people whose symptoms haven’t responded to serotonin-based treatment.

The same mechanism is behind ketamine’s use in treatment-resistant depression, where the evidence base is much larger.

What the Research Actually Shows So Far

The most-cited study is a small randomized trial from 2013, in which people with near-constant obsessions received either a single IV ketamine infusion or a placebo. Those who received ketamine reported a rapid reduction in obsessive thoughts. Across the randomized trials reviewed in the 2026 systematic review, a single IV ketamine infusion produced a rapid anti-obsessional response in roughly 50 to 60 percent of participants.

There are important limits to that picture, and they’re worth stating plainly:

  • The studies are small, often a dozen or so participants each, and only a handful of randomized trials exist.
  • The benefit from a single infusion tends to fade within days to a couple of weeks.
  • Ketamine is not FDA-approved for OCD, so its use here is off-label.
  • Spravato (esketamine) is FDA-approved for treatment-resistant depression and MDD with acute suicidal ideation, not for OCD.

None of this means ketamine doesn’t help with OCD. It means it should be approached as a carefully considered option within a broader treatment plan, not as a stand-alone fix.

Why Ketamine Works Best Alongside ERP Therapy

The most encouraging finding in the OCD research isn’t about ketamine alone. Studies that paired a ketamine infusion with exposure and response prevention therapy reported improvement lasting weeks to months, considerably longer than ketamine on its own.

That fits with how ketamine is understood to work more broadly. It appears to open a temporary window of increased neuroplasticity, a period when the brain is more flexible and better able to form new patterns. For someone with OCD, ERP is where those new patterns get built: gradually facing the triggers that drive compulsions without performing them. Ketamine may make that work more accessible for some people, especially those who have found ERP too difficult to engage with while symptoms are severe.

For that reason, patients considering ketamine for OCD at Parker Neuroscience are encouraged to have, or be connected with, a therapist trained in ERP, and care is coordinated with that therapist rather than delivered in isolation.

Who Might Be a Candidate

Ketamine may be worth discussing if OCD symptoms have persisted despite adequate trials of standard medication and therapy, and especially if depression or anxiety is also present, which is common alongside OCD. A full evaluation reviews your diagnosis, treatment history, current medications, and safety considerations before any treatment is offered.

Not everyone with OCD is a good candidate, and an honest evaluation will say so. Some people are better served by adjusting their medication, intensifying ERP, or exploring other options first. Ketamine also carries short-term effects during treatment, including temporary dissociation and changes in blood pressure and heart rate, which is why it’s only given with continuous clinical monitoring. A small number of case reports have also described mood changes in the days after treatment in people with OCD and a history of depression, which is one reason follow-up after each session matters as much as the session itself.

What Treatment Looks Like

If IV ketamine is recommended, the experience is the same structured, monitored outpatient visit used for every condition treated at Parker Neuroscience: an evaluation, baseline vitals, a private treatment room with continuous monitoring, and a ride home arranged in advance. Our first appointment walk-through covers what a session actually feels like from start to finish, and our overview of ketamine treatment in Omaha covers what to know before starting.

Because intrusive thoughts and a loss of control are often central to OCD, preparation before treatment matters a great deal. What that looks like in practice, including how difficult moments are handled during a session, is covered in our piece on psychological safety in ketamine care.

Setting Realistic Expectations

Some people with OCD notice a meaningful reduction in obsessive thoughts after ketamine. Others notice a partial or short-lived change, and some don’t respond. That variability is true of ketamine across every condition it’s used for, and it’s covered in more depth in why ketamine helps some patients more than others. The goal is never ketamine for its own sake. It’s finding the combination of treatments that gives you the best chance at lasting relief.

Frequently Asked Questions About Ketamine for OCD

Does ketamine work for OCD?

Early research shows a single IV ketamine infusion can rapidly reduce obsessive thoughts for some people, with roughly half of participants responding in small randomized trials. The effect from one infusion tends to be short-lived, and the strongest results so far come from pairing ketamine with exposure and response prevention therapy.

Is Spravato approved for OCD?

No. Spravato (esketamine) is FDA-approved for treatment-resistant depression and MDD with acute suicidal ideation. If ketamine-based treatment is used for OCD, it is IV ketamine used off-label after a full evaluation.

Do I still need therapy if I get ketamine for OCD?

Yes. Exposure and response prevention therapy remains the foundation of OCD treatment. Ketamine appears to work best alongside it, and studies that combined the two reported longer-lasting improvement than ketamine alone.

How long do the effects of ketamine last for OCD?

After a single infusion, the reduction in obsessive thoughts in research studies generally faded within days to a couple of weeks. Pairing ketamine with ERP therapy was associated with improvement lasting considerably longer.