Intramuscular (IM) Ketamine

Intramuscular (IM) ketamine involves injecting the medication directly into a large muscle, typically the upper arm (deltoid) or thigh. With a bioavailability of approximately 93%, it is nearly as efficiently absorbed as intravenous (IV) ketamine but does not require continuous line placement.

This method is highly favored in ketamine-assisted psychotherapy (KAP) settings, as it allows the patient to settle into a comfortable space without the physical tether of an IV line.

The IM experience is distinct from IV due to its rapid onset and slightly different absorption curve:

1. Administration: A quick injection is given into the muscle.
2. Onset: Effects begin rapidly, typically within 3 to 5 minutes.
3. Duration: The active dissociative phase generally lasts 40 to 60 minutes. Because the dose is absorbed all at once, the peak is often more pronounced than a gradual IV drip.
4. Monitoring: Vital signs are monitored intermittently to ensure patient safety while preserving a quiet, therapeutic environment.

IM ketamine is often slightly more affordable than IV ketamine due to lower equipment and nursing overhead. Sessions typically range from $350 to $600. Like most generic ketamine therapies for mental health, it is considered off-label and is rarely covered by commercial insurance.

Side effects are similar to IV infusions—dissociation, dizziness, and nausea—with the addition of potential soreness at the injection site. Because the entire dose is given at once, the subjective experience can feel more intense initially compared to a slow IV drip.