IV ketamine is ketamine delivered directly into your bloodstream through a vein, most commonly used today as an off-label treatment for severe depression and chronic pain. While the FDA approves ketamine only as an anesthetic, clinics across the U.S. now offer low-dose infusions for psychiatric and pain conditions that haven’t responded to standard treatments. A typical session lasts about 40 minutes, costs $400 to $800 out of pocket, and uses a fraction of the dose given during surgery.
How IV Ketamine Works in the Brain
Most antidepressants target serotonin and take weeks to kick in. Ketamine works through an entirely different system: glutamate, the brain’s primary excitatory chemical messenger. The chain of events starts when ketamine blocks certain receptors on inhibitory brain cells. Those inhibitory cells normally keep excitatory neurons in check, so when ketamine quiets them, excitatory neurons fire more freely. The result is a surge of glutamate in the prefrontal cortex, the region involved in mood, decision-making, and emotional regulation.
That glutamate surge is just the beginning. It triggers a cascade that activates growth-signaling pathways inside neurons, particularly ones involved in producing a protein called BDNF (brain-derived neurotrophic factor). BDNF essentially acts as fertilizer for brain connections. Within hours, new synapses, the junctions where neurons communicate, begin forming. This process, called synaptogenesis, is thought to be what makes ketamine’s antidepressant effects so fast compared to conventional medications. Animal studies confirm this: when researchers block either BDNF signaling or the growth pathway called mTOR, ketamine loses both its ability to build new synapses and its antidepressant effect.
Ketamine also appears to promote synapse growth even when neurons are at rest, through a separate mechanism that boosts BDNF production independently of the glutamate surge. This dual action may help explain why the drug can produce noticeable mood shifts within hours rather than weeks.
What IV Ketamine Is Used For
Ketamine’s only FDA-approved use is as an anesthetic for surgery. Everything else, including treatment for depression, anxiety, PTSD, and chronic pain, is considered off-label prescribing. Off-label doesn’t mean unproven or illegal; it means a doctor is using an approved drug for a purpose that hasn’t gone through the full FDA approval process for that specific condition. This is common in medicine, but it does affect insurance coverage.
The most widely studied off-label use is for treatment-resistant depression, generally defined as depression that hasn’t improved after trying two or more standard antidepressants. Chronic pain conditions, including complex regional pain syndrome, neuropathic pain, and fibromyalgia, are the other major category. Some clinics also offer infusions for suicidal ideation, where ketamine’s rapid onset can be particularly valuable since traditional antidepressants take weeks to work.
Typical Dosing and Treatment Schedule
For depression, the standard dose is 0.5 mg/kg of body weight infused over 40 minutes. Some patients respond to doses as low as 0.1 mg/kg, while others need up to 0.75 mg/kg. Sessions have been studied at durations ranging from 2 to 100 minutes, though 40 minutes is the most common. These are subanesthetic doses, meaning they’re well below what would be used for surgery, so you remain conscious throughout.
Most clinics structure treatment in two phases. The induction phase typically involves a series of infusions over one to three weeks, often six sessions total. After that, some patients move to maintenance infusions spaced weeks or months apart to sustain the benefits. The ideal frequency and duration remain an open question. Some patients do well with occasional boosters, while others with highly refractory conditions continue treatment for much longer.
Chronic pain protocols can look quite different. One standardized approach involves five consecutive daily infusions of 0.5 mg/kg over 40 minutes each. But published protocols vary widely: some use single two-hour infusions, others use continuous multi-day treatments at higher doses, and settings range from outpatient clinics to inpatient hospital units.
How Well It Works
Single ketamine infusions produce rapid antidepressant effects, sometimes within hours. The catch is that those benefits typically fade within days. That’s why repeated infusions are the norm. In a 2025 randomized clinical trial published in JAMA Psychiatry, 46.9% of patients receiving serial ketamine infusions for depression achieved a clinical response (meaningful improvement in symptoms), and 43.8% reached full remission. For comparison, the placebo group showed a 33.3% response rate and 30% remission rate.
These numbers are notable because the patients studied had already failed other treatments. A roughly 44% remission rate in treatment-resistant depression is significant, though it also means more than half of patients don’t achieve full remission with ketamine alone. It’s typically used alongside other therapies rather than as a standalone treatment.
What an Infusion Session Feels Like
You’ll sit or recline in a clinical setting, usually a private or semi-private room. A nurse places a standard IV line, and the ketamine drips in slowly over the session. Clinics are required to have resuscitation equipment on hand and staff trained in advanced cardiac life support, regardless of the dose being used.
During the infusion, most people experience dissociation: a floating, detached feeling where your sense of time and body boundaries shifts. Some describe it as dreamlike. Visual distortions, mild nausea, and a sense of emotional openness are common. These effects are dose-dependent and typically resolve within an hour or two after the infusion stops. Your blood pressure and heart rate will be monitored throughout, since ketamine tends to raise both temporarily.
Before your first session, the clinic will review your medical history. People at higher risk for cardiovascular events may need a baseline heart tracing. Those with liver conditions or a history of heavy alcohol use may need liver function tests before and after treatment, since ketamine is processed through the liver. You’ll be asked not to eat beforehand, similar to preparation for any procedure involving sedation. You won’t be able to drive yourself home afterward.
Cost and Insurance Coverage
Because IV ketamine for depression and pain is off-label, most insurance plans do not cover it. Out-of-pocket costs for a single infusion typically run between $400 and $800, though some specialty clinics charge more. A full induction series of six infusions can therefore cost $2,400 to $4,800 or higher before any maintenance sessions.
Some clinics will provide detailed documentation, including superbills and diagnosis codes, that you can submit to your insurance company for potential reimbursement. Success with these claims varies widely depending on your plan and insurer. It’s worth noting that esketamine (a nasal spray derivative of ketamine sold under the brand name Spravato) does have FDA approval for treatment-resistant depression and is more likely to be covered by insurance, though it requires administration in a certified healthcare setting as well.
IV Ketamine vs. Esketamine Nasal Spray
Ketamine is a mixture of two mirror-image molecules. Esketamine is just one of those molecules, isolated and delivered as a nasal spray. The practical differences matter: esketamine has FDA approval specifically for treatment-resistant depression, which makes insurance coverage more likely. IV ketamine gives clinicians more precise control over dosing, since the drug enters the bloodstream directly rather than being absorbed through nasal tissue. Many clinicians consider IV ketamine more flexible, particularly for chronic pain applications where doses and durations vary significantly between patients.
Risks and Side Effects
Short-term side effects during and after an infusion include dissociation, dizziness, nausea, increased blood pressure, and blurred vision. These are expected at subanesthetic doses and generally resolve within a couple of hours. More concerning are the longer-term risks associated with repeated use. Frequent, high-dose ketamine exposure has been linked to bladder damage (causing urinary urgency and pain) and liver toxicity, though these complications are more associated with recreational abuse than with clinical dosing protocols.
Ketamine is a Schedule III controlled substance, meaning it carries a recognized potential for psychological dependence. Clinics that follow best practices limit the frequency and duration of treatment to minimize this risk, but it’s a real consideration for anyone entering long-term maintenance treatment. People with a history of substance use disorders, uncontrolled high blood pressure, or active psychosis are generally not considered good candidates for ketamine therapy.