Ketamine for Chronic Pain: What to Know

Ketamine's story didn't start with depression — anesthesiologists have used it for pain control for decades, and chronic pain remains one of the most common reasons people seek out infusion clinics. But "ketamine for pain" is a genuinely different treatment from "ketamine for depression": different doses, different session lengths, different evidence, and often different clinics.

Why ketamine works differently for pain

Chronic pain — especially neuropathic pain — involves a process called central sensitization: the nervous system's pain circuits become hypersensitive, amplifying signals long after the original injury. Ketamine blocks NMDA receptors, which sit at the center of that amplification loop. The goal of a pain infusion isn't to numb you for an afternoon; it's to reset sensitized circuits so pain levels stay lower for weeks or months afterward.

Conditions with the most evidence

Consensus guidelines from the American Society of Regional Anesthesia and Pain Medicine (published jointly with anesthesia and pain societies in 2018) reviewed the evidence:

• Complex regional pain syndrome (CRPS) has the strongest support — multiple trials show meaningful relief lasting up to weeks or months after infusion series.
• Neuropathic pain (nerve injury, spinal cord injury, phantom limb) has moderate supporting evidence.
• Fibromyalgia and migraine show short-term benefit in studies, with less certainty about durable relief.
• For general chronic pain without a neuropathic component, evidence is weakest — a fair thing to press a clinic on.

Everything here is off-label, so insurance rarely covers it, though pain infusions are sometimes delivered in hospital settings where more of the visit is billable — see our insurance guide.

How pain protocols differ from mental health protocols

This is the part most people don't expect:

• Higher doses, longer sessions. Mood treatment typically uses ~0.5 mg/kg over 40 minutes. Pain protocols often run several hours at higher hourly doses, sometimes on consecutive days. For severe CRPS, some centers run multi-day series.
• More medical intensity. Higher doses mean more dissociation, more blood-pressure effect, and more need for monitoring — this is infusion medicine, not a spa service. Anesthesiologist- or pain-physician-led clinics are the norm here.
• Different measurement. Outcomes are tracked with pain scores and function, not PHQ-9 depression scales.
• Adjunct medications (like magnesium or clonidine) are more commonly co-administered in pain settings.

If you're dealing with both chronic pain and depression — an extremely common combination — tell the clinic. Dosing can't optimize for both simultaneously, but mood improvement is a well-documented side benefit of pain protocols, and vice versa.

What relief typically looks like

Honest expectations, based on the trial data: a successful infusion series commonly reduces pain scores substantially for weeks to a few months, after which maintenance ("booster") infusions are used to sustain the effect. Some patients get months of relief per booster; some get little benefit at all. Nobody credible promises permanent results from a single series.

Questions to ask a pain-focused clinic

1. Who runs the infusions, and what's their background in pain medicine or anesthesia?
2. What protocol do you use for my condition — dose, duration, number of sessions?
3. What monitoring is in place during multi-hour infusions?
4. How do you measure success, and when would you conclude it isn't working?
5. What does maintenance look like, and what does the full picture cost annually?

Most of the general advice in how to choose a ketamine clinic applies doubly here, because pain protocols are more medically demanding than mood protocols.

Bottom line

For CRPS and neuropathic pain, ketamine infusions are a legitimate, guideline-acknowledged option when standard treatments have failed. For fibromyalgia and migraine, they're a reasonable maybe with shorter-lived benefits. For everything else, be appropriately skeptical and ask hard questions about evidence. Look for medically serious, anesthesia-literate providers — our directory lists clinics nationwide with contact details so you can ask about pain-specific protocols directly.