Dissociative anesthetic, FDA-approved (as Spravato) for treatment-resistant depression.
Ketamine is a synthetic compound first produced in 1962 by Parke-Davis chemist Calvin Stevens and introduced into US clinical use in 1970 as a general anesthetic.1 Pharmacologically, it is a non-competitive antagonist of the NMDA glutamate receptor — meaning it works on a completely different neurotransmitter system than the "classic" psychedelics (psilocybin, LSD, DMT), which act primarily as 5-HT2A serotonin receptor agonists. For that reason, many researchers classify ketamine as a "dissociative anesthetic" rather than a psychedelic proper. In therapeutic use the two categories overlap enough that most clinicians and policymakers treat ketamine as part of the same conversation.
There are three distinct access models in the US today, and they are not interchangeable:
| Model | What happens | Typical cost per session | Insurance |
|---|---|---|---|
| In-clinic IV infusion | 0.5 mg/kg over ~40 minutes, monitored by anesthesia-trained staff. Most research uses this route. | $400–$800 | Rarely covered for depression; sometimes covered for chronic pain. |
| Spravato (esketamine) nasal spray | FDA-approved 2019 for treatment-resistant depression, 2020 for MDD with suicidal ideation. Self-administered in a certified office under 2-hour observation.2 | $590–$885 (drug) + clinic observation | Frequently covered; REMS program required. |
| At-home oral lozenges (telehealth) | Compounded rapid-dissolve troches, prescribed after a telehealth psychiatric visit. Patient self-administers at home. | $150–$400/month | Not covered; paid out-of-pocket. |
The first two are evidence-based and REMS-supervised. The third — at-home telehealth — is the fastest-growing and the most regulated-grey: it was enabled by DEA telehealth flexibilities during COVID-19 and tightened substantially after the 2023 death of actor Matthew Perry, which was ruled to involve ketamine obtained outside his then-active clinic program.
The foundational finding — a rapid antidepressant effect within hours of a single sub-anesthetic dose — was reported by Berman et al. in 2000.3 That effect has been replicated dozens of times since. A 2023 meta-analysis in the British Journal of Psychiatry of 36 trials found that ketamine produced significantly greater antidepressant response than placebo through 72 hours, with effect sizes larger than conventional antidepressants.4
The harder question is durability. A single infusion's benefit typically fades within days to weeks. Spravato's pivotal SUSTAIN-1 maintenance trial demonstrated that repeat dosing every 1–2 weeks reduced relapse versus placebo, which is the basis for its current dosing schedule.5 How long the durability effect persists after discontinuation is an active research question.
A 2020 Phase 3 trial (ASPIRE-I) led to Spravato's 2020 expanded indication for major depressive disorder with acute suicidal ideation or behavior — a patient population conventional antidepressants serve poorly because they take weeks to work. Ketamine's hours-scale onset is the entire clinical argument.
Chronic-use concerns are the more important long-term question, and the reason reputable clinics push back against high-frequency at-home protocols:
Contraindications include uncontrolled hypertension, recent cardiovascular events, active psychosis, and pregnancy.
Ketamine is a Schedule III controlled substance under the US Controlled Substances Act — the same schedule as buprenorphine and anabolic steroids. That makes it the only US-legal option among the therapies in this catalog. Two federal frameworks govern clinical use: the DEA's Schedule III prescribing rules, and the FDA's REMS program for Spravato specifically.
State-level law matters for telehealth: the DEA's flexibilities on remote controlled-substance prescribing (inherited from the COVID-19 public health emergency) have been repeatedly extended. Changes here directly affect whether at-home oral ketamine remains available through telehealth-only providers — one of the policy developments we track on analysis.
If cost is a barrier: start by asking whether your insurance covers Spravato for treatment-resistant depression. That is the path with the most regulatory guardrails and the most insurance support. The REMS program requires that you take it in a certified provider's office under observation — there's no home version.
If you want the most-studied intervention: IV infusion at a clinic run by an anesthesiologist or psychiatrist with anesthesiology backup. Ask explicitly about protocols, screening, and follow-up. Most research trials use the 0.5 mg/kg over 40 minutes infusion protocol — clinics that deviate sharply from that warrant extra scrutiny.
If you are considering telehealth at-home: verify that the prescribing clinician is licensed in your state, has a real psychiatric evaluation process (not a 10-minute form), and includes integration / follow-up care. The telehealth model is the one where the quality variance across providers is largest.
Outcomes across all three access models correlate with whether the patient has a therapist working alongside the medical prescriber. This is the part of the treatment the FDA does not directly regulate — it is "off-label" but evidence-supported. See the integration therapy guide for what a good integration relationship looks like and how to find one.