IV vs. IM Ketamine: Comparing How Ketamine Is Given

Clinics deliver ketamine in several ways, and the route of administration affects the cost, the experience, and how precisely the dose can be controlled. The two you'll see most often in clinics are intravenous (IV) infusion and intramuscular (IM) injection, with nasal esketamine and oral lozenges rounding out the picture.

IV infusion: the most controllable route

An IV infusion delivers ketamine directly into a vein over a set period — typically around 40 minutes for depression protocols, longer for some chronic-pain protocols. Dosing usually starts around 0.5 mg/kg of body weight and is adjusted from there based on your response.

Why clinics and researchers like IV:

• Complete bioavailability. Everything administered reaches your bloodstream, making dosing the most precise of any route.
• Real-time control. The infusion rate can be slowed, paused, or stopped mid-session if you're having a difficult experience or your blood pressure rises too much. No other route allows this.
• Research alignment. Most of the clinical evidence for ketamine in depression comes from IV studies, so IV protocols track the research most closely.

Downsides: it requires an IV line, a pump, and more staff attention, which makes it the most expensive option — and some people simply dislike needles-plus-tubing.

IM injection: simpler and often cheaper

An IM injection delivers the full dose into a muscle (usually shoulder or thigh) in one shot. Bioavailability is high — meaningfully better than nasal or oral routes — and effects come on quickly.

Why some clinics prefer IM:

• Simplicity. No IV line or infusion pump, shorter appointments, lower overhead — savings that often show up in the per-session price.
• Comparable effects for many patients. For a given total dose, the antidepressant response appears broadly similar for many people.

Downsides: once injected, the dose can't be adjusted or stopped. The onset is also steeper — the dissociative effects arrive faster and can feel more intense than a gradual infusion, which some patients prefer and others don't.

Nasal esketamine (Spravato)

Spravato is its own category: an FDA-approved nasal spray of esketamine, self-administered under supervision at certified clinics and usually billed through insurance. Nasal absorption is less complete and somewhat more variable than IV or IM, which is one reason the fixed dosing (56 mg or 84 mg) differs from weight-based infusion protocols. We compare it to generic ketamine in detail in Ketamine vs. Spravato.

Oral and sublingual lozenges

Swallowed or sublingual ketamine has the lowest and most variable absorption of the common routes — much of the dose is metabolized before reaching circulation. Lozenges are mostly used for at-home maintenance under telehealth or hybrid programs, not as a primary induction treatment. The convenience is real, but so is the reduced precision, and at-home use means no clinical monitoring — worth discussing carefully with a prescriber.

Quick comparison

• Dose precision: IV (best) → IM → nasal → oral
• Ability to adjust mid-session: IV only
• Typical cost per session: IV (highest) → IM → lozenges; Spravato depends heavily on insurance
• Session logistics: all in-clinic routes require monitoring afterward and a ride home

What actually matters when choosing

For most patients starting out, the choice is between IV and IM at a local clinic, and honest clinics will tell you the difference is smaller than the marketing suggests. Ask:

1. What dose and protocol do you use, and how do you adjust it between sessions?
2. Who monitors me during the session, and what are their credentials?
3. What does each route cost here, all-in?
4. If the first route doesn't work well for me, can we switch?

A clinic that answers those four questions directly is worth more than any particular route. You can compare what clinics near you offer in our directory, and see what a first session looks like before you book.