A ketamine treatment session typically lasts about 40 minutes, during which you sit or recline in a clinic while the drug produces a range of dissociative, sedative, and sometimes mildly hallucinogenic effects. The experience varies depending on how ketamine is delivered and why you’re receiving it, but the core of every session involves a period of altered perception followed by a monitored recovery window before you go home. Here’s what the full process looks like from start to finish.
How Ketamine Is Delivered
There are three main ways clinics administer ketamine. The most common is an IV infusion, where the drug drips directly into a vein over the course of the session. Some clinics use intramuscular injections instead, which are quicker to set up but absorb slightly differently. The third option is a nasal spray called Spravato, which contains esketamine (a close chemical relative of ketamine) and is the only form with FDA approval specifically for treatment-resistant depression.
With IV or intramuscular delivery, effects are typically felt within an hour or sooner, often within minutes for IV. Spravato’s effects take longer to notice, usually appearing between two and four hours after administration. The method your provider recommends depends on the condition being treated and what’s available at the clinic.
What Happens Before the Infusion
You’ll likely be told not to eat or drink for a few hours before your appointment. Your provider may also ask you to pause certain medications ahead of time. When you arrive, staff will check your vitals (blood pressure, heart rate, oxygen levels) and get you settled in a recliner or bed, often in a private or semi-private room. Some clinics offer eye masks, blankets, or calming music to help set the mood. An IV line is placed if you’re receiving an infusion, and then the session begins.
What the Session Actually Feels Like
This is what most people searching this topic really want to know, and it’s genuinely hard to describe because the experience is unlike most medications. Ketamine is a dissociative drug, meaning it creates a sense of separation between your mind and your body. Many people report feeling like they’re floating, or that the room has shifted in some subtle way they can’t quite articulate. Your sense of time may stretch or compress. Colors and sounds can seem more vivid or more distant.
Some people experience mild visual effects: geometric patterns, shifting light, or dreamlike imagery. Others describe a deep emotional openness, where thoughts about their life surface in unexpected ways. The intensity varies with the dose and the person. At lower doses commonly used for depression, most people remain aware of where they are and can respond to questions, even if they feel “far away.” At higher doses or with certain protocols, the dissociation can feel more immersive.
Not every sensation is pleasant. Nausea is one of the more common side effects, and some people feel dizzy or experience a temporary rise in blood pressure. A small number of people find the dissociation uncomfortable or anxiety-provoking, particularly during a first session when they don’t know what to expect. Clinics monitor your blood pressure, heart rate, and oxygen saturation every five to fifteen minutes throughout the infusion. If your blood pressure spikes significantly or you develop respiratory symptoms like shortness of breath, the infusion is stopped.
What Happens After the Infusion Ends
Once the ketamine stops flowing, the dissociative effects begin fading relatively quickly, but you won’t feel completely normal right away. Clinics keep you for a minimum two-hour monitoring period after the session. During that time, staff check that your vital signs have returned to baseline, your thinking feels clear, and any nausea or dizziness has subsided to a manageable level.
You will not be allowed to drive yourself home. Most clinics require you to arrange a ride in advance. The standard guidance is to avoid driving for the rest of the day and only get behind the wheel the next morning if you feel fully alert and clear-headed. Plan on the entire appointment, including recovery, taking roughly three to four hours out of your day.
How Ketamine Works in the Brain
Traditional antidepressants work on serotonin and can take weeks to produce results. Ketamine takes a completely different route. It blocks a specific type of receptor involved in how brain cells communicate, which triggers a burst of a chemical messenger called glutamate. That burst essentially kick-starts the brain’s ability to form new connections between neurons, a process called neuroplasticity.
A small neuroimaging study found that in patients with depression who had measurable deficits in brain connectivity, ketamine actually increased the density of those connections. The degree of improvement correlated with both symptom relief and the intensity of dissociative effects during the session. In other words, the strange feelings during the infusion may be a sign that the drug is actively reshaping neural pathways. These changes share features with other forms of long-lasting brain plasticity, where a brief period of circuit activation produces durable improvements in how those circuits function.
The Typical Treatment Schedule
Ketamine treatment happens in two phases. The first is an induction phase: six to eight IV infusions spread over three to six weeks, usually two to three sessions per week. This concentrated schedule is designed to build up the neuroplastic changes that produce symptom relief.
After induction, your provider evaluates how you’ve responded and decides on a maintenance schedule. Maintenance infusions, sometimes called boosters, are spaced further apart. Some people come in monthly, others quarterly, and some only need a session once or twice a year to sustain the benefits. The schedule is highly individual and depends on how long your symptom relief lasts between sessions.
For Spravato specifically, the schedule looks a bit different. It’s typically given twice a week for the first four weeks, then tapered to once a week or once every other week.
Cost and Insurance Coverage
This is where ketamine treatment gets complicated. IV ketamine infusions are considered off-label for depression and chronic pain, and most insurance plans, including Medicare, do not cover them. Medicare classifies ketamine infusion therapy as “investigational” for these conditions. Out-of-pocket costs for IV infusions vary by clinic and region but generally run several hundred dollars per session, which adds up quickly during the induction phase.
Spravato is the exception. Because it has FDA approval for treatment-resistant depression, it’s more likely to be covered by insurance, including Medicare Part B, as long as it’s administered by your prescribing physician in a licensed facility. Under Medicare Part B, after meeting a $257 deductible, you’d typically pay 20% of the approved cost. If you have a Medicare Advantage plan, your costs depend on the specific plan’s terms.
What to Expect Over Multiple Sessions
First sessions tend to be the most disorienting simply because the sensations are unfamiliar. Many people find that by their second or third infusion, they have a better sense of what to expect and can relax into the experience more easily. Some people notice mood improvements within hours of their first session, while for others the benefits build gradually across the induction series.
The dissociative effects during each session are temporary and resolve the same day. The therapeutic effects on mood or pain, by contrast, can last days to weeks. The gap between those two timelines is part of what makes ketamine unusual: a 40-minute experience of altered consciousness can produce changes in brain connectivity that persist long after the drug has cleared your system.