What Is Ketamine Infusion Therapy?
Ketamine is an FDA-approved anesthetic that has been used safely in hospitals since the 1960s. In the last two decades, researchers discovered that sub-anesthetic doses produce rapid, powerful antidepressant effects — often within hours of a single infusion.
Unlike traditional antidepressants that modulate serotonin or norepinephrine, ketamine works primarily through the glutamate system — the brain’s most abundant excitatory neurotransmitter. It blocks NMDA receptors, triggering a cascade that increases BDNF (brain-derived neurotrophic factor) and promotes the rapid formation of new synaptic connections. Depression weakens these connections; ketamine helps rebuild them.
The ketamine clinic landscape
Ketamine infusion clinics have grown rapidly across the US — from roughly 100 in 2017 to over 1,000 by 2026. They range from psychiatrist-led practices to anesthesiologist-run infusion centers to multi-location chains.
Quality varies significantly. Some clinics provide comprehensive psychiatric care with ketamine as one tool; others operate more like infusion mills. Due diligence matters.
How Treatment Works
A standard initial ketamine protocol involves 6 infusions over 2-3 weeks, followed by maintenance infusions as needed.
Psychiatric assessment, medical history review, vitals baseline. Some clinics require a referring psychiatrist; others evaluate in-house.
Sub-anesthetic ketamine (0.5mg/kg) delivered through an IV line. You're awake but may experience dissociation, visual changes, and altered perception.
Effects wear off within 1-2 hours. You'll need someone to drive you home. Cannot drive or operate machinery for 24 hours.
After the initial 6 infusions, most patients need boosters every 2-8 weeks to maintain benefits. Frequency is titrated to your response.
Ketamine vs. TMS: Head-to-Head
| Factor | Ketamine | TMS |
|---|---|---|
| Speed | Hours | 2-3 Weeks |
| Duration of Effect | 1-3 weeks per infusion | 6-12 months after course |
| FDA Status | Off-label | FDA Cleared |
| Abuse Potential | Yes (Schedule III) | None |
| Dissociation | Expected (~60%) | None |
| Insurance Coverage | Rarely covered | Widely covered |
| Annual Cost | $5,000-$15,000+ | $6,000-$12,000 (one-time) |
| Drive After? | No — need a ride | Yes, immediately |
Side Effects and Risks
During infusion (resolve within 1-2 hours):
- Dissociation and perceptual changes (feeling “floaty,” visual distortions)
- Nausea (about 15-20%)
- Elevated blood pressure and heart rate
- Dizziness
- Headache
Potential concerns with ongoing use:
- Bladder toxicity (cystitis) with chronic use — rare at clinical doses but documented
- Cognitive effects with prolonged, frequent dosing
- Psychological dependence — wanting the dissociative experience
- Liver function changes — rare but monitored
Who should NOT use ketamine
- Active psychosis or schizophrenia
- Uncontrolled hypertension
- Active substance use disorder (especially ketamine or PCP)
- Pregnancy
- Increased intracranial pressure
Cost and Insurance
Ketamine infusion therapy is almost never covered by insurance because it’s off-label for depression. This is the biggest barrier for most patients.
| Item | Cost |
|---|---|
| Initial 6 infusions | $2,400-$4,800 |
| Maintenance infusion | $400-$800 each |
| Annual maintenance (monthly) | $4,800-$9,600 |
| Psychiatric evaluation | $200-$500 |
Some clinics offer package pricing, payment plans, or sliding scale fees. HSA/FSA funds can typically be used.
When Ketamine Makes Sense Over TMS
- Acute suicidality — when hours matter, not weeks
- TMS non-response — if TMS didn’t work, ketamine targets a completely different mechanism
- Chronic pain comorbidity — ketamine has analgesic properties TMS doesn’t
- Can’t commit to daily sessions — ketamine requires only 6 initial visits vs 30-36 for TMS
When TMS Makes Sense Over Ketamine
- Insurance coverage — TMS is widely covered; ketamine usually isn’t
- No dissociation desired — TMS has zero psychoactive effects
- Longer-lasting results — TMS benefits persist months after treatment ends
- Substance use history — TMS has zero abuse potential
- Need to drive/work same day — TMS has no recovery period
For a detailed breakdown, read our TMS vs. Ketamine comparison. Use our clinic finder to find providers offering both options.