Posted on February 4, 2026

For individuals struggling with treatment-resistant depression, anxiety, PTSD, OCD, chronic suicidality, or other difficult-to-treat mental health conditions, ketamine-based therapies have become one of the most promising breakthroughs in modern psychiatry.

However, many patients quickly discover that there are several different forms of ketamine treatment available — most commonly:

• IV Ketamine Infusions
• IM Ketamine Injections
• Spravato® (Esketamine Nasal Spray)

While all three treatments work on the glutamate/NMDA receptor system and can provide rapid relief from depression symptoms, they differ significantly in:

• Insurance coverage
• Cost
• Bioavailability
• Dosing flexibility
• Speed of onset
• Duration of effects
• Treatment experience
• FDA approval status
• Clinical customization

Understanding these differences can help patients make a more informed decision about which option may best fit their clinical needs, financial situation, and treatment goals.

What Is the Difference Between Ketamine and Spravato?

Ketamine is a medication that has been used medically for decades as an anesthetic. In mental health treatment, providers commonly use “racemic ketamine,” which contains two mirror-image molecules:

• R-ketamine
• S-ketamine

Spravato® is different because it only contains the S-ketamine molecule (esketamine). It was developed into a nasal spray formulation and became FDA-approved in 2019 for treatment-resistant depression and depressive symptoms with suicidal ideation.

IV and IM ketamine treatments, on the other hand, are considered “off-label” psychiatric uses of generic ketamine. Although off-label, they are widely used in specialized psychiatric and ketamine clinics throughout the United States.

Insurance Coverage: One of the Biggest Deciding Factors

For many patients, insurance coverage becomes the primary reason they choose Spravato over IV or IM ketamine.

Spravato® Insurance Coverage

Spravato is FDA-approved for:

• Treatment-resistant depression (TRD)
• Major depressive disorder with suicidal ideation

Because it is FDA-approved, most commercial insurance plans cover Spravato treatments when medical necessity criteria are met.

Patients typically must:

• Have failed at least three antidepressants from at least two different classes (example: SSRI, SNRI, NDRI, TCA, etc)
• Receive treatment in a REMS-certified clinic
• Stay monitored for at least 2 hours after treatment
• Continue taking an oral antidepressant alongside Spravato

Depending on insurance, out-of-pocket costs may be very low compared to IV or IM ketamine. 

IV and IM Ketamine Coverage

IV and IM ketamine for depression are considered off-label treatments. Because of this:

• Most insurance companies do not cover the treatment itself
• Patients usually pay out of pocket
• HSA/FSA accounts may sometimes be used

Typical costs vary by clinic and region, but IV ketamine often costs more than IM ketamine because:

• IV infusions require infusion pumps and IV supplies
• Sessions are often longer
• IV administration requires continuous infusion management

IM ketamine is often viewed as a more cost-effective alternative because it provides similarly high bioavailability without the expense of IV infusion equipment. 

Bioavailability: Why It Matters

Bioavailability refers to how much of the medication actually reaches systemic circulation and becomes usable by the body.

This is one of the most important clinical differences between IV, IM, and Spravato.

IV Ketamine: Highest Bioavailability

IV ketamine has nearly 100% bioavailability because the medication goes directly into the bloodstream. 

Advantages include:

• Extremely precise dosing
• Predictable absorption
• Rapid onset
• Ability to carefully titrate the experience

Because providers can continuously adjust the infusion rate, IV ketamine offers the highest degree of control over the treatment experience.

IM Ketamine: Very High Bioavailability

IM ketamine generally has around 90–93% bioavailability. 

Many clinics and patients appreciate IM ketamine because it:

• Provides very strong absorption
• Is less invasive than IV therapy
• Often costs less than IV
• Can still provide deep therapeutic experiences

Many patients find IM ketamine to be an excellent middle ground between affordability and effectiveness.

Spravato®: Lower and More Variable Absorption

Spravato’s intranasal route has significantly lower bioavailability — typically around 45–50%. 

Unlike IV or IM administration, nasal absorption can vary depending on:

• Nasal congestion
• Nasal anatomy
• Improper administration technique
• Drainage into the throat/stomach

This lower and less predictable absorption is one reason why some patients who do not respond to Spravato may still respond well to IV or IM ketamine.

Dosing Flexibility: One of Spravato’s Biggest Limitations

One major limitation of Spravato is that it only comes in two FDA-approved dosing options:

• 56 mg
• 84 mg

This creates challenges for some patients because psychiatric symptoms vary greatly between individuals.

Some patients:

• Respond beautifully to lower doses
• Need higher doses for symptom relief
• Need dose adjustments over time
• Need individualized titration

With IV and IM ketamine, providers can tailor dosing much more precisely based on:

• Body weight
• Sensitivity
• Symptom severity
• Tolerance
• Treatment goals
• Response history

This customization is one of the biggest clinical advantages of IV and IM ketamine.

Some patients who do not respond adequately to Spravato may respond once individualized ketamine dosing is introduced. Patient discussions and clinical observations frequently reference this issue. 

Onset of Effects

All ketamine-based treatments work substantially faster than traditional antidepressants.

Traditional antidepressants may take:

• 4–8 weeks to work

Ketamine treatments may improve symptoms within:

• Hours
• Days
• Sometimes after the very first treatment
• Most require at least 6 treatments to see whether ketamine treatment is working for them

IV Ketamine

IV ketamine typically begins working within:

• 10 minutes after starting infusion (since the IV line is primed with saline), but once ketamine starts infusing, 1-5 minutes

Because the medication enters directly into the bloodstream, patients often notice:

• Rapid dissociation
• Emotional release
• Deep introspection
• Perceptual changes

IM Ketamine

IM ketamine usually begins within:

• 1-5 minutes

Many patients describe the onset as:

• Smooth
• Rapid
• Intense but manageable

Because the medication is delivered all at once instead of slowly infused, some patients feel IM experiences are more immersive.

Spravato®

Spravato generally begins working within:

• 5–15 minutes 

However, many patients report the experience feels:

• Milder
• Less immersive
• Shorter-lasting

Some patients prefer this gentler experience, especially if they are nervous about dissociation.

Duration and Offset 

IV Ketamine

IV infusions are commonly administered over:

• 45 minutes

The acute psychoactive experience usually fades relatively quickly after infusion ends. 

One advantage is that providers can slow or stop the infusion if the experience becomes overwhelming.

IM Ketamine

IM ketamine often produces:

• Faster peak intensity

Effects commonly last:

• 20-40 minutes (mostly depends on dose and patient's metabolism)

Because the injection cannot be “turned down” once administered, patients experience the full dose trajectory.

Spravato®

Spravato sessions require:

• Mandatory 2-hour monitoring under REMS regulations

Many patients experience:

• Sedation
• Dizziness
• Dissociation
• Fatigue

Patients cannot drive themselves home after any of these treatments.

Which Treatment Is Strongest?

This depends on what is meant by “strongest.”

IV Ketamine

Usually offers:

• The most precision
• Highest bioavailability
• Most medically controlled experience

IM Ketamine

Often offers:

• Very powerful therapeutic experiences
• Strong bioavailability
• More cost efficient

Spravato®

Offers:

• FDA approval
• Insurance accessibility
• Simpler administration
• Less invasive treatment

However, some patients feel Spravato produces a less robust effect than IV or IM ketamine because:

• Only esketamine is used
• Bioavailability is lower
• Dosing is less customizable

Patient experiences vary greatly, and some individuals do extremely well with Spravato while others respond better to IV or IM ketamine. 

Conditions Commonly Treated

Spravato®

FDA-approved specifically for:

• Treatment-resistant depression
• Depression with suicidal ideation

IV and IM Ketamine

Often used off-label for:

• Depression
• Anxiety disorders
• PTSD
• OCD
• Bipolar depression
• Chronic pain
• Suicidal ideation

Because IV and IM ketamine are off-label, providers often have more flexibility in tailoring treatment plans to individual psychiatric presentations. 

The Treatment Experience

Patients often want to know:
“What does it actually feel like?”

While experiences vary, ketamine treatments may involve:

• Altered perception
• Emotional release
• Increased introspection
• Dissociation
• Visual imagery
• Enhanced neuroplasticity
• Reduced depressive rumination

Many clinics combine ketamine treatment with psychotherapy or integration work to help patients process emotions and insights that arise during treatment.

The subjective experience may differ between routes:

• IV = smoother and more adjustable
• IM = deeper peak intensity for some patients
• Spravato = often milder and shorter

Which Option Is Right for You?

There is no universal “best” option.

The right treatment depends on:

• Severity of depression
• Prior treatment failures
• Financial considerations
• Insurance coverage
• Sensitivity to medication
• Desire for dosing flexibility
• Comfort with dissociative experiences
• Need for individualized treatment

In general:

Spravato may be ideal for:

• Patients wanting insurance-covered treatment
• Patients preferring FDA-approved care
• Patients comfortable with nasal spray administration
• Patients needing a more affordable option

IV ketamine may be ideal for:

• Patients wanting maximum dosing precision
• Patients seeking highly individualized care
• Patients with severe or complex treatment resistance
• Patients wanting the highest bioavailability

IM ketamine may be ideal for:

• Patients seeking strong effectiveness with lower cost than IV
• Patients wanting highly customizable treatment
• Patients comfortable with injections
• Patients wanting shorter clinic sessions without IV placement

Final Thoughts

Ketamine-based therapies are transforming how clinicians treat severe depression and other difficult mental health conditions.

For many patients, these treatments provide hope after years of unsuccessful medication trials.

Spravato offers accessibility and insurance coverage through an FDA-approved pathway. IV and IM ketamine offer greater dosing flexibility, higher bioavailability, and highly individualized treatment approaches.

The best choice ultimately depends on each patient’s:

• Clinical history
• Financial situation
• Treatment goals
• Biological response
• Personal preferences

A thorough evaluation with an experienced ketamine provider can help determine which treatment approach is most appropriate for your unique needs.