Some people move through one antidepressant after another and never really get their footing back. When two or more honest attempts with standard medication haven’t helped, that has a name — treatment-resistant depression, or TRD — and it’s exactly where IV ketamine has shifted the conversation over the last decade. The thing that grabbed everyone’s attention is speed: where a typical antidepressant takes weeks to work, ketamine can act in hours to days.
Here’s a level-headed look at what the evidence actually supports.
If you are in crisis or having thoughts of harming yourself, please call or text 988 (the Suicide and Crisis Lifeline) or go to your nearest emergency room. This article is educational and isn’t a substitute for urgent care.
How is ketamine different from standard antidepressants?
Most antidepressants work on serotonin and related systems, and they usually need four to six weeks to reach full effect. Ketamine takes a different road entirely — the NMDA receptor and the glutamate system — which is thought to rapidly encourage new connections between brain cells. In practice, that’s why improvement can show up in hours to days rather than weeks. That speed is a big reason the research interest has been so intense, especially for severe and urgent cases.
What does the evidence show?
It’s genuinely encouraging. Several meta-analyses, plus a 2024 umbrella review, give large-scale support for repeated-dose IV ketamine in treatment-resistant depression, with higher rates of response and remission than placebo.
Two findings stand out:
- Speed, again. Ketamine and its cousin esketamine produce some of the fastest drops in measures of suicidal thinking of anything we have — which is why they’re studied so closely in urgent situations.
- IV versus intranasal. A 2024–2025 comparison found IV ketamine produced a larger reduction in depression scores than intranasal esketamine (Spravato), and worked faster — sometimes with improvement right after the first treatment.
Now the caveats, because they matter. Ketamine’s effect, fast as it is, doesn’t hold on its own. It tends to fade over days to weeks, which is why it’s given as a series of infusions and usually paired with ongoing psychiatric care. It works best as one piece of a real plan, not as a standalone rescue.
IV ketamine vs. Spravato (esketamine)
You may have run into Spravato, the FDA-approved intranasal esketamine spray — a close chemical cousin of ketamine. The practical differences: Spravato is FDA-approved specifically for TRD and comes as a nasal spray, while IV ketamine is used off-label but allows precise dosing, tends to act faster, and in head-to-head data has shown somewhat larger symptom reduction. Both are given under monitoring. Which one fits depends on the person.
What’s treatment like?
Ketamine for depression is a slow IV infusion at a low, sub-anesthetic dose, given in a calm, monitored room. You stay awake but may feel a floating or detached sensation during the session that lifts soon after. It usually starts as a series of infusions over a few weeks, sometimes followed by maintenance sessions. Plan on someone driving you home.
What are the risks?
During the infusion, the usual side effects are dissociation, dizziness, nausea, and short-term rises in blood pressure or heart rate — the reason you’re monitored the whole time. In the studies, side effects were generally mild to moderate and short-lived, mostly clearing within a day. It isn’t right for everyone, though: certain heart conditions, uncontrolled blood pressure, active psychosis, or substance-use concerns call for careful screening first.
Who’s a candidate?
IV ketamine for depression is generally considered for adults with treatment-resistant depression — usually meaning an inadequate response to at least two standard antidepressants — after a thorough evaluation. It’s most often coordinated alongside the mental-health care a patient already has.
Frequently asked questions
How fast does IV ketamine work for depression?
Often within hours to a few days — much faster than standard antidepressants. The effect from a single infusion is temporary, which is why a series is used.
Is IV ketamine FDA-approved for depression?
IV ketamine is used off-label. The related intranasal drug esketamine (Spravato) is FDA-approved for treatment-resistant depression.
How many infusions will I need?
Most protocols start with a series over a couple of weeks, sometimes followed by maintenance. The exact plan is individualized.
Is it a cure for depression?
No. Ketamine can bring rapid relief, but it fades over time, so it’s used as part of an ongoing plan rather than a one-time fix.
Can I stop my other antidepressants?
Not on your own. Ketamine is typically used alongside — not instead of — your existing care, and any medication changes should be coordinated with your providers.
Struggling with depression that hasn’t responded to medication?
At University Pain Consultants – Regenerative Medicine, I provide IV ketamine infusion therapy in a safe, monitored setting and evaluate whether it’s an appropriate option for you. We serve Riverside and the greater Inland Empire.
Call 951-900-3253 to schedule a consultation.
Learn more about our IV Ketamine Infusion program » · Read our IV Ketamine FAQ »
Medical disclaimer: This article is for general educational purposes only and is not medical advice, nor a substitute for professional mental health care. It does not establish a physician-patient relationship. The use of IV ketamine for depression is off-label. If you are in crisis, call or text 988. Always consult a qualified healthcare provider before pursuing any treatment.
