Ketamine therapy has shown remarkable results for treatment-resistant depression, anxiety, PTSD, and chronic pain. But responsible medicine means being equally clear about when a treatment should not be used. At Discreet Ketamine, Dr. Ben Soffer screens every patient carefully because safety is not negotiable.

Here is a straightforward guide to the medical and psychiatric conditions that may make ketamine therapy inappropriate -- or that require additional evaluation before proceeding.

Absolute Contraindications

These conditions generally rule out ketamine therapy entirely:

Ketamine Allergy

This is rare but it is an absolute stop. If you have had an allergic reaction to ketamine in any setting -- surgical, dental, recreational, or therapeutic -- you cannot safely receive it again.

Active Psychosis or Schizophrenia Spectrum Disorders

Ketamine can temporarily alter perception, cognition, and sense of reality. In patients with a history of psychosis, schizophrenia, or schizoaffective disorder, these effects can trigger or worsen psychotic episodes. This is one of the clearest contraindications in the clinical literature, and we do not make exceptions.

Uncontrolled Hypertension

Ketamine reliably raises blood pressure and heart rate. For patients whose blood pressure is already elevated and uncontrolled, this additional cardiovascular stress poses genuine risk -- including the risk of hypertensive crisis, stroke, or cardiac events.

If you have high blood pressure that is well-managed with medication, ketamine may still be an option. We evaluate this on a case-by-case basis with careful monitoring. Read more in our detailed article on ketamine and hypertension.

Conditions Requiring Careful Evaluation

These conditions do not automatically disqualify you, but they require additional screening, coordination with your other providers, or modified treatment protocols:

Bipolar Disorder Without Mood Stabilization

Ketamine can trigger manic or hypomanic episodes in patients with bipolar disorder, particularly if they are not currently taking a mood stabilizer. If you have bipolar I or II and are stable on a mood stabilizer such as lithium, valproate, or lamotrigine, ketamine therapy may be appropriate with close monitoring. Without mood stabilization, the risk of precipitating mania is too high.

Cardiovascular Disease

Beyond hypertension, other cardiovascular conditions -- including coronary artery disease, heart failure, arrhythmias, and history of stroke -- warrant thorough evaluation. Ketamine's sympathomimetic effects (increased heart rate, blood pressure, and cardiac output) require us to weigh the mental health benefits against cardiovascular risk. See our full discussion of ketamine and cardiovascular disease.

Moderate to Severe Liver Disease

Ketamine is metabolized primarily by the liver. In patients with significant hepatic impairment, the drug may be cleared more slowly, leading to prolonged or intensified effects. We review liver function labs before approving treatment for patients with known liver conditions.

Active Substance Use Disorder

This is nuanced. Ketamine itself is a Schedule III controlled substance with abuse potential. In patients with active, uncontrolled substance use disorders -- particularly those involving dissociatives, opioids, or alcohol -- introducing another psychoactive substance requires extreme caution. Patients who are in stable recovery may be candidates, but we assess each situation individually and often coordinate with addiction specialists.

Pulmonary Conditions

Severe respiratory conditions, particularly those that compromise airway protection or baseline oxygen levels, require evaluation. While respiratory depression from sublingual ketamine at therapeutic doses is extremely rare, patients with conditions like severe COPD or obstructive sleep apnea warrant additional consideration. See our article on ketamine and pulmonary conditions.

Situational Contraindications

These are not medical conditions per se, but circumstances that make safe treatment impossible:

No Peer Supervisor Available

At Discreet Ketamine, we require every patient to have a peer supervisor -- a trusted adult who is present in the home during the active session. This person does not need medical training; they need to be sober, present, and able to contact emergency services if necessary. If you cannot arrange a peer supervisor, at-home treatment is not safe.

Pregnancy or Breastfeeding

There is insufficient safety data on ketamine use during pregnancy and lactation. We avoid prescribing ketamine to pregnant or breastfeeding patients unless there is a compelling clinical justification and no safer alternative -- a decision that would require consultation with the patient's obstetrician.

No Access to Psychological Support

Ketamine therapy works best as part of a broader treatment plan that includes some form of psychological support -- whether that is formal psychotherapy, structured integration sessions, or at minimum a therapeutic relationship with a provider who can help you process what emerges. Patients who are seeking ketamine purely as a standalone medication without any psychological support may not be well-served by this approach. Learn more about the integration process.

Seeking Recreational Effects

We evaluate patients for medical indications. If someone's primary motivation is to experience the dissociative or psychedelic effects of ketamine rather than to treat a diagnosed mental health condition, they are not an appropriate candidate for treatment. This is not a judgment -- it is a matter of medical ethics and legal compliance.

Significant Medication Conflicts

Certain medications require evaluation before ketamine can be safely added. MAOIs, some antihypertensives, and drugs that significantly affect the CYP3A4 enzyme pathway may interact with ketamine in clinically meaningful ways. We review every patient's medication list in detail. For more, see our article on medication safety with ketamine.

The Screening Process at Discreet Ketamine

Every patient who applies for treatment at Discreet Ketamine completes a comprehensive medical intake. Dr. Soffer, a board-certified internist, personally reviews each case to determine whether at-home ketamine therapy is safe and appropriate. When we identify a contraindication, we explain why and, where possible, suggest alternative approaches or steps that might make treatment possible in the future -- such as stabilizing blood pressure or establishing a mood stabilizer regimen.

Our at-home ketamine therapy is available in Florida and New Jersey, starting at $250/month. If you want to find out whether ketamine therapy is appropriate for your specific situation, check your eligibility.

Disclaimer: Compounded ketamine for anxiety, depression, PTSD, and chronic pain is not FDA approved.

When Ketamine Is Not Appropriate: Medical and Psychiatric Contraindications