How Ketamine Infusion Works
Last reviewed and updated: June 30, 2026.
Key Takeaways
| IV ketamine protocol | 6 infusions over 2–3 weeks; 40 min–2 hr each; $400–$800/infusion; out-of-pocket |
| Spravato (esketamine) | FDA-approved nasal spray for TRD and suicidal ideation; administered in-clinic; insurance-covered with prior auth |
| At-home oral ketamine | Growing but weaker evidence base; lower bioavailability than IV; convenience vs. reduced dose precision; misuse concerns |
| What to expect during | Dissociation, floating, perceptual shifts — expected and transient; resolves within 1–2 hrs; not dangerous |
| Clinic vetting | Require MD/anesthesiologist oversight, mental health screening, integration support; red flags: high-pressure sales, no screening |
So you’ve decided to try out a ketamine therapy and you don’t really know what to expect? Here’s all you need to know about how a ketamine infusion works.
Ketamine is one of the most popular psychedelics nowadays, especially as it gains more attention from the mainstream media. Likewise, given its positive testimonials, it’s no wonder why more ketamine clinics are opening around the world.
Interested in joining a Psychedelics Clinical Trial? Sign up here now and we will connect you with a clinical trial in your area when one becomes available.
As a dissociative anesthetic, ketamine has also been classified as a hallucinogen. These types of drugs alter consciousness, involving acute changes in somatic, perceptual, cognitive, and affective processes. Therefore, it produces a psychedelic effect.
Technically, it is not classified as psychedelic because it doesn’t produce it’s effect via activation of the 5HT2A receptor like classic psychedelics (LSD, Psilocybin, etc.) However it definitely produces a psychedelic like experience/effect through dissociation, so it is often called one.
Psychedelics are gaining popularity these days for their healing capabilities. Psilocybin (or magic mushrooms), ayahuasca, and MDMA aren’t the only ones getting the attention. Ketamine is generating much of the interest, causing a revolution in alternative treatment options.
With positive results concerning anxiety and depression, questions about ketamine treatments have been popping in many psychotherapists’ offices, in hopes that this alternative treatment will finally help them get some relief they’ve been desperately waiting for but none of the current therapies provide.
RELATED: The One Thing You Should Do Before Starting Ketamine Therapy
Ketamine Treatments
When it comes to ketamine treatments, there are two different ways one can go about it.
- Esketamine. This type of ketamine is taken as a nasal spray (Spravato). Patients still need to visit a doctor prior to receiving treatment. And They are required to do all Spravato treatments at a doctor’s office, not just prior to receiving treatment. The doctor or health care clinic has to be a certified to provide Spravato as well. Esketamine is typically prescribed in conjunction with a conventional oral antidepressant, as it may enhance the effect of those drugs.
A little more background on Spravato:
The FDA guidance states that the person should be on any antidepressant, while starting Spravato. So if you are not on one, then you are supposed to be started on one, or just keep taking what you already take. However, this is not an absolute requirement. If you’ve failed multiple medications in the past, or if you start one and it causes side effects for example, the doctor can still take you off the antidepressant and continue with Spravato.
Find a REMS-certified Spravato clinic near you in our verified provider directory.
Spravato doesn’t “enhance” oral antidepressants. Because the major research studies conducted by Janssen Pharmaceuticals to prove Spravato’s efficacy involved a design where both control group and Spravato group were on antidepressants, that’s why the FDA put that language in the Spravato label.
- Intravenous Infusions. This type of ketamine treatment includes six or more doses spread out over three weeks. This may then be followed with booster infusions once a month, if necessary. Unlike Esketamine, ketamine infusions aren’t regulated or approved by the FDA. Since it enters the bloodstream directly, this is typically much stronger, often yielding better results.
A little more on intravenous infusions:
Booster infusion requirements can vary between patients. It can range from every 2 weeks to every 6 months. The overwhelming majority of patients require ongoing maintenance infusions (i.e, booster infusions) to maintain benefits.
What About the Lack of FDA Regulations?
It’s not accurate to connect lack of FDA approval to uncertainty or speculation. The lack of FDA regulation definitely allows some room for ketamine to be administered in different ways (and some of the ways clinics do it, may not be very safe or effective). Ketamine actually has more research studies behind it compared to esketamine, over a longer period of time. Esketamine definitely had larger scale study for the purpose of presenting to FDA for approval. Overall Ketamine is more effective than esketamine.
Looking for ketamine therapy? Click here to find top rated ketamine clinics near you
Ketamine Infusion 101
Similar to any IV, a ketamine infusion is attached to a vein through a tube. It then enters the bloodstream and disperses throughout the body.
Before getting a ketamine infusion, the patient needs to go through a thorough checklist in order to determine eligibility.
The checklist includes a severe diagnosis of several mental health issues like bipolar disorder or personality disorder.
Ketamine Therapy Exclusion
Those who are not eligible for to receive a ketamine infusion are those with the following.
- Active substance abuse (Alcohol, cannabis, non-prescribed medications, etc.) Ketamine infusions are very helpful for active substance use disorders (specifically alcohol, cocaine, opioid withdrawal, benzodiazepine withdrawal). Some clinics will treat these conditions, usually when administered by psychiatrists or addiction medicine specialists
- Active manic episode
- Active psychosis
- History of increased intracranial pressure
- Pregnancy (current)
- Uncontrolled hypertension
- Acute or unstable cardiovascular disease
- Previous negative response to ketamine
Once the provider deems the patient eligible for receiving treatment, a pre-treatment consultation is the next step. And most of the time the eligibility to receive treatment is happening the same time as the pre-treatment medical clearance consultation. This is where they receive all the necessary information about the ketamine infusions — like what to expect. Info regarding symptoms and recovery. As well as obtaining medical clearance based on their situation.
Following approval, treatment begins. It usually lasts around 45 minutes, with the typical frequency of 2-3 infusions per week over the course of 2-3 weeks. (Basically 6 infusions over 2-3 weeks.)
Throughout the infusion, the clinic closely monitors the patient. Vital signs include heart rate, blood pressure, respiratory rate, oxygen saturation, level of consciousness, signs and symptoms of potential ketamine toxicity, and dissociative effects, as ketamine impacts everyone differently.
Once ketamine therapy is complete, the clinic still monitors the patient in case any new symptoms occur. He/she is then able to leave with a designated driver, as side effects do occur.
Common Ketamine Side Effects
Below are some side effects from ketamine treatment.
- A dream-like feeling and/or drowsiness
- Double vision or blurred vision
- Dizziness
- Jerky muscle movements
- Vomiting or nausea
- Loss of appetite
- Sleep disturbances or insomnia
- High blood pressure
Recovery includes vital signs trending down to baseline, resolution of the more intense effects such as dissociation. Once a patient feels more embodied, and able to remain steady on their feet, then they can be discharged with designated driver. Some perceptual changes can linger for another few hours in some people, which will resolve after they get a good night sleep. For others, they may feel back to baseline completely very quickly.
RELATED: What Does Ketamine Feel Like?
So, How Does Ketamine Infusion Actually Work?
Researchers aren’t yet entirely sure how ketamine works. It behaves like an antidepressant in the way that it helps manage severe depression, especially in situations when other treatments fail. But it is a verified fact throughout clinical literature that ketamine works through an entirely different mechanism than antidepressant medications, therefore explaining its efficacy.
Ketamine reduces signals that trigger inflammation, which often aligns with mood disorders such as depression and anxiety. It also appears ketamine effects the communication across specific areas within the brain, targeting specific receptors.
Ketamine IV infusion targets the NMDA receptors in the brain and it binds to them, increasing the amount of a neurotransmitter glutamate in the space between neurons. Glutamate then activates the connections in a different receptor called the AMPA receptor. Working in unison, these NMDA and activated AMPA receptors release additional molecules that help neurons communicate along new pathways. This complex process is synaptogenesis, and it affects mood, cognition, and thought patterns.
Ketamine does a lot to the human body. While this is a main reason why researchers are bullish about its positive results, further studies are necessary. There are lots of pros and cons, but still plenty to learn about the therapeutic effects of the psychedelic.
The Ketamine Infusion Landscape in 2026: What Has Changed
When this article was first published, IV ketamine infusions for depression and chronic pain were still operating in a relatively uncharted clinical space — a growing but fragmented off-label practice. The landscape in 2026 looks meaningfully different in several key ways, and patients evaluating ketamine treatment today are navigating a more complex menu of options than existed even two years ago.
Spravato has reached mainstream status. Esketamine nasal spray (Spravato), the FDA-approved formulation of ketamine, crossed $400 million in quarterly revenue in 2025 — a level that puts it on pace for blockbuster designation. Its approvals for Treatment-Resistant Depression (TRD) and Major Depressive Disorder with acute suicidal ideation (MDSI) mean it is now widely available through psychiatrists and specialty infusion centers, and critically, insurance-covered with prior authorization for qualifying patients. IV ketamine and Spravato use the same drug class but differ substantially: Spravato is self-administered as a nasal spray under 2-hour in-clinic observation, while IV ketamine is administered intravenously with precise dose titration. IV ketamine is still out-of-pocket, typically $400–$800 per infusion; Spravato’s insurance coverage changes the financial calculus dramatically for patients who qualify. Neither is better in an absolute sense — the delivery route, insurance status, and clinical context all matter.
Telehealth oral ketamine has exploded — with important caveats. Companies including Mindbloom, Ketamine One, and Joyous now offer sublingual and oral ketamine protocols delivered via telehealth, often with remote preparation and integration support. These services are accessible and substantially cheaper than IV infusion — but there are real trade-offs. Oral and sublingual ketamine has lower bioavailability than IV (roughly 20–30% compared to near-100% for IV), and the evidence base for remote-administered ketamine is weaker than for clinic-based IV infusion. Regulatory and misuse concerns have increased as at-home access has scaled: several programs have tightened their screening protocols in response to reports of misuse. Telehealth ketamine is not inherently unsafe, but patients should understand they are accepting a different risk and efficacy profile than IV infusion.
Clinic quality is now the critical variable. With 700+ ketamine clinics now operating across the United States, the range of quality is enormous. The best clinics pair infusions with structured preparation and integration support, operate under anesthesiologist or physician oversight, conduct thorough mental health screening, and follow evidence-based protocols developed from academic research. The worst are high-volume operations with minimal clinical oversight, inadequate screening, and no integration support — settings where ketamine is administered as a commodity rather than a therapy. Patients evaluating a clinic should ask about physician oversight, integration support structure, screening protocol, and what happens if they experience adverse effects. Red flags include high-pressure sales practices, discounted “package deal” framing without clinical rationale, and absence of mental health screening.
Frequently Asked Questions
How many ketamine infusions do you need?
The standard initial protocol for depression is 6 infusions over 2–3 weeks, based on the dosing schedule used in the foundational clinical research. Most patients who respond to ketamine begin to feel effects by the third or fourth infusion, though some respond earlier. After the initial series, the durability of response varies: some patients maintain benefit for months without additional treatment, while others benefit from monthly or quarterly “booster” infusions. There is no single universal protocol — clinics may adjust the number and timing based on individual response. Spravato (esketamine nasal spray), the FDA-approved alternative, uses twice-weekly administration for four weeks as the induction phase, followed by once-weekly and then biweekly maintenance. Patients should discuss response-based adjustments with their provider rather than committing to a fixed number of sessions upfront.
What does a ketamine infusion feel like?
The experience varies by individual and dose, but the most commonly described sensations during an IV ketamine infusion include dissociation (a sense of separation from one’s body or surroundings), perceptual shifts (colors may appear more vivid, sounds may seem altered), floating or weightlessness, and an unusual relationship to time. Some patients describe the experience as dreamlike or mildly hallucinatory; others find it more subtle — a quiet settling of mental noise. The experience is dose-dependent: lower doses used for pain management may produce minimal perceptual effects, while higher doses for depression typically produce more noticeable dissociation. Importantly, these effects are not dangerous — they are expected, transient, and resolve fully within 1–2 hours of the infusion ending. Most clinics have patients recline in a comfortable chair with an eye mask and music; the setting is designed to support a calm, inward-focused experience. Having a trusted person accompany you and drive you home afterward is standard practice.
Is Spravato the same as a ketamine infusion?
Spravato (esketamine) and IV ketamine are related but not identical. Both are ketamine-class drugs that work via NMDA receptor antagonism and produce similar antidepressant effects. The key differences are: (1) Formulation — Spravato uses esketamine (the S-enantiomer of ketamine) as a nasal spray; IV ketamine uses racemic ketamine (both enantiomers) administered intravenously. (2) FDA approval — Spravato is FDA-approved for TRD and MDSI; IV ketamine is off-label for depression. (3) Insurance — Spravato is insurance-covered for qualifying diagnoses with prior authorization; IV ketamine is out-of-pocket. (4) Setting and experience — Spravato patients self-administer the spray and observe in-clinic for two hours; IV patients receive a continuous infusion over 40–90 minutes with IV access in place. (5) Dose control — IV allows more precise real-time dose titration. Neither is universally superior; the right choice depends on diagnosis, insurance coverage, and clinical context. A psychiatrist can help navigate the decision.
Is at-home ketamine therapy safe?
Telehealth ketamine (oral or sublingual, administered at home) has grown rapidly and can be appropriate for some patients, but it is not equivalent to IV infusion in a clinical setting and comes with real trade-offs. On the safety side: oral and sublingual ketamine have a gentler, more gradual onset than IV, which reduces the intensity of dissociative effects and makes adverse reactions less acute. However, without in-person monitoring, there is no clinical backup if someone has an adverse reaction, and the home setting introduces risk of misuse, falls during dissociation, or interaction with other substances. From an efficacy standpoint, lower bioavailability means the therapeutic dose reaching the brain is substantially lower than IV, and the evidence base for home-delivered oral ketamine is far thinner than for IV infusion. Programs that include mandatory preparation and integration support and that conduct rigorous mental health screening before enrollment are safer than those that function as prescription-and-ship services. Patients with cardiac conditions, certain psychiatric comorbidities, or a history of substance misuse should discuss these factors carefully with a prescribing physician before pursuing at-home protocols.
