Buccal Ketamine: Absorption Rate and Clinical Use

Buccal ketamine administration means placing a ketamine tablet, lozenge, or liquid between the cheek and gum so the drug absorbs through the buccal mucosa, the thin, blood-vessel-rich lining inside the cheek, rather than being swallowed. This route bypasses some of the liver's first-pass metabolism that swallowed oral ketamine undergoes, which gives it higher bioavailability than an oral capsule but lower bioavailability than intravenous (IV) or intramuscular (IM) injection. Buccal ketamine has no FDA-approved indication. When clinics or compounding pharmacies provide it, it is prescribed off-label, most often as an at-home maintenance dose used between clinic-based IV or IM sessions.

What Buccal Administration Actually Means

The buccal mucosa is the inner lining of the cheek. Because it sits close to a dense network of small blood vessels, some drugs placed there can diffuse directly into systemic circulation instead of traveling through the digestive tract first. That matters for ketamine because swallowed doses pass through the liver before reaching the bloodstream, a process called first-pass metabolism that breaks down a large share of the drug before it can take effect.

Buccal dosing is closely related to sublingual dosing, where the medication sits under the tongue instead of against the cheek. Both routes aim to exploit the same mucosal absorption pathway, and the two terms are sometimes used loosely, or interchangeably, in clinical materials, though the exact tissue contact and absorption rate can differ slightly.

Absorption and Bioavailability

Bioavailability describes what fraction of a dose actually reaches the bloodstream intact. Published pharmacokinetic studies indexed on PubMed estimate buccal and sublingual ketamine bioavailability in the range of roughly 25% to 50%, depending on the study, formulation, and how long the dose stays in contact with the mucosa before being swallowed. That's substantially higher than the roughly 20% to 25% typically reported for swallowed oral ketamine, but far below the near-complete bioavailability of IV or IM delivery.

How Buccal Ketamine Is Used Clinically

Most buccal ketamine in circulation today comes from compounding pharmacies as troches or rapid-dissolve tablets, prescribed as part of a broader treatment plan rather than as a stand-alone therapy. A common pattern is that a patient completes an initial series of clinic-supervised IV or IM sessions, then transitions to periodic buccal or sublingual dosing at home to sustain effects between visits. You can read more about how these building-block routes compare in our guide to ketamine treatment methods.

Because buccal dosing skips a needle, some patients and prescribers prefer it to intramuscular ketamine injection or subcutaneous ketamine administration for routine maintenance. It is distinct from esketamine, sold under the brand name Spravato, which is the only ketamine-related medication with FDA approval, specifically as a nasal spray for treatment-resistant depression when used alongside an oral antidepressant. Generic buccal ketamine carries no such approval, and prescribing it for depression, chronic pain, or other conditions is an off-label clinical decision made between a patient and a licensed prescriber.

Onset generally runs slower than injected routes; for a full breakdown of how quickly each method takes effect, see our comparison of ketamine onset time by route of administration.

Side Effects and Safety Considerations

Buccal ketamine carries the same general side-effect profile as other routes, including dissociation, drowsiness, dizziness, nausea, and short-term increases in blood pressure and heart rate. Because ketamine is a Schedule III controlled substance under federal law, it carries recognized potential for misuse, and frequent or high-dose use over time has been associated in case reports with bladder and urinary tract irritation. Anyone starting buccal dosing should have a plan with their prescriber for what to do if effects feel stronger than expected, and should avoid mixing it with alcohol or other central nervous system depressants.

This is educational information, not medical advice. Ketamine's use for depression and most mental health conditions remains off-label, talk with a licensed clinician about whether any route, including buccal, fits your specific medical history.