Is Ketamine Therapy Safe? A Physician's Answer

"Is this safe?" is the first question nearly every patient asks me, and it deserves a thorough answer. As a board-certified physician prescribing at-home ketamine, I want to give you the same information I share with my own patients, including the risks worth knowing about, not just the reassuring version.

The short answer: at the sub-anesthetic doses used for psychiatric treatment, ketamine has a well-established safety profile backed by decades of clinical use. Like any medication, it comes with considerations you should understand before starting.

What "sub-anesthetic dose" actually means

Ketamine was FDA-approved as an anesthetic in 1970 and has been used safely in hospitals for over 50 years. The doses we use for depression, anxiety, and PTSD are a fraction of anesthetic doses, typically 10-25% of what would be used in surgery.

At these lower doses, ketamine produces its therapeutic effects on mood and neuroplasticity while maintaining a wide safety margin. Same medication pediatric emergency departments use regularly because of its favorable safety profile. If ketamine were as dangerous as its recreational reputation suggests, pediatric ERs would not use it.

Side effects during treatment

Most side effects happen during the session itself and resolve within one to two hours.

Dissociation (very common). A feeling of detachment from your surroundings ("floating," "dreamlike"). This is part of the therapeutic mechanism, not an adverse effect separate from it. Most patients find it manageable and many find it valuable.

Nausea (common). Roughly 15-30% of patients experience mild nausea. Usually manageable with anti-nausea medication taken beforehand, an empty stomach, and a comfortable position. Resolves as the medication wears off.

Elevated blood pressure (common). Ketamine can transiently raise blood pressure by 15-25%. For healthy patients, this is clinically insignificant. For patients with uncontrolled hypertension, it's a contraindication we screen for.

Dizziness and drowsiness (common). Lightheadedness or sleepiness during and shortly after the session. This is why the 6-hour no-driving rule exists and why we require a sober sitter present.

Visual changes (less common). Heightened colors, patterns, or blurred vision during the session. Resolves completely as the medication clears.

Serious risks worth discussing

Serious adverse events at sub-anesthetic dose in screened patients are rare but worth naming directly.

Bladder issues. Long-term, frequent recreational ketamine use has been associated with bladder damage. At therapeutic doses and treatment frequencies used clinically (typically 10+ sessions over 4-8 weeks, then tapering), this risk is very low. We monitor for urinary symptoms and would adjust treatment if they emerged.

Psychological distress. In rare cases the dissociative experience can be unsettling, particularly for patients with a history of psychosis or active substance use disorders. This is why thorough screening is essential before treatment starts: patients in those categories need different care, not ketamine.

Cardiovascular events. Extremely rare at sub-anesthetic doses, but possible in patients with severe, uncontrolled cardiovascular disease. Screened during evaluation.

Dependence potential. Ketamine is a Schedule III controlled substance. At therapeutic doses and supervised frequencies, the risk of dependence is low. Physician oversight includes monitoring for any signs of misuse, and treatment frequency is capped at what's clinically appropriate rather than what a patient requests.

Who shouldn't receive ketamine therapy

Not everyone is a candidate. Our eligibility screening looks for these contraindications:

• Active psychosis or schizophrenia (ketamine can worsen psychotic symptoms)
• Uncontrolled hypertension (transient BP elevation could be dangerous)
• Severe cardiovascular disease (including recent heart attack or unstable angina)
• Active substance use disorder involving ketamine, PCP, or other dissociatives
• Pregnancy or breastfeeding (insufficient safety data)
• Untreated hyperthyroidism (can amplify cardiovascular effects)

Some of these are absolute ("no" regardless of circumstance). Others are relative ("not right now"; let's treat the underlying issue first, then revisit). Our screening sorts those during evaluation.

The people I say no to are the people I'm protecting. If I say no to you, that's not a rejection. It's me telling you ketamine isn't the right tool for your specific situation.

How physician supervision shapes safety

The at-home model works because the screening is the safety net. Since a clinician isn't in the room with you during sessions, the pre-treatment evaluation and ongoing monitoring have to be more thorough than they'd need to be in a clinic where nurses are three feet away. Our full safety protocols post walks through what that looks like in practice.

Pre-treatment screening. Before prescribing, I review your complete medical history, current medications, mental health background, and cardiovascular picture. This is the step that catches potential interactions and contraindications.

Individualized dosing. Your dose is calibrated to your body weight, medical history, and response. We start conservatively and adjust based on your actual experience, not a preset formula.

Your in-room safety net. Your sober adult sitter is the on-site responder for the rare situations that need one. The sitter isn't ceremonial; they're the safety layer the clinic model provides with nursing staff.

Ongoing monitoring. Regular check-ins track your response, side effects, and overall progress. This is fundamentally different from a one-off prescription with no follow-up, and it's how we catch issues before they become problems.

The comparison most patients don't do

When patients ask me about ketamine safety, I often ask them to weigh the alternative: continued suffering from treatment-resistant depression, with its own well-documented risks including suicide, substance abuse, and physical health decline.

The medications many patients are already taking (SSRIs, SNRIs, benzodiazepines) all carry their own side effect profiles. Some of those are more significant long-term than ketamine's. The question is rarely "is this perfectly safe?" but rather "does the benefit outweigh the risk for my specific situation?"

For most patients who have failed two or more antidepressant trials, the answer is clear. The response rates for ketamine in treatment-resistant depression are 60-70%, onset is measured in hours rather than weeks, and the side effects are confined to treatment sessions rather than daily.

When to call your care team

Most side effects need no intervention beyond patience; they resolve on their own within one to two hours. Contact your care team if you experience:

• Severe or persistent nausea beyond the session
• Chest pain or heart palpitations
• Dissociation lasting more than 3 hours after dosing
• Urinary symptoms (pain, frequency, blood)
• Persistent anxiety or mood changes between sessions

These situations are uncommon but important to address. Having direct physician access, not a generic support line, matters here.

Making an informed decision

Informed consent means understanding both the potential benefits and the real risks. I've tried to present both without either minimizing the risks or overstating them.

Frequently Asked Questions

What are the most common side effects during a ketamine session?

The most common in-session effects are mild dissociation (a feeling of detachment from your body or surroundings), brief nausea, slight blood-pressure elevation, and dizziness if you stand up too quickly. These typically resolve within 60-90 minutes after the session ends. Most patients describe the experience as gentle and dreamlike at therapeutic doses. Persistent side effects after sessions are uncommon.

Can ketamine therapy cause addiction?

At supervised therapeutic doses given in a structured protocol, the addiction risk is low. Addiction risk in the medical literature is associated with chronic high-dose recreational use: typically daily use of supratherapeutic doses, often nasal or IV, taken for euphoric rather than therapeutic effect. Patients with active substance use disorders are screened out of at-home ketamine programs because they have an elevated risk profile that isn't safely manageable in a home setting.

Is ketamine therapy safe for the bladder and kidneys?

Bladder toxicity (ketamine cystitis) is a real but dose- and duration-dependent risk seen primarily in heavy chronic recreational users (often daily use over years). At the doses and intermittent schedule used in psychiatric treatment (typically 10+ sessions over 4-8 weeks), clinical bladder issues are very rare. Kidney effects from supervised therapeutic ketamine are not a documented concern.

Who should NOT do at-home ketamine therapy?

Disqualifying conditions include uncontrolled high blood pressure (ketamine transiently raises BP), active psychosis or schizophrenia spectrum disorders, severe untreated substance use disorder, current pregnancy or active breastfeeding, severe untreated cardiovascular disease, and certain rare conditions like elevated intracranial pressure. These are screened during the eligibility assessment before treatment is approved.

Ready to find out if you're a candidate?

The honest answer to "is this safe for me?" depends on your specific medical history, current medications, and underlying conditions. The eligibility check is how we sort that.

• Eligibility check: tovanihealth.com/eligibility (5 minutes, FL and NJ residents)
• Phone: 561-468-6981
• What you get back: an honest answer. Sometimes "yes, let's evaluate." Sometimes "no, here's why, and here's what might help instead." Either outcome is the right one when it's the true one.

Benjamin Soffer, DO — Tovani Health

Related reading: our at-home safety protocols, the support person's role, ketamine during pregnancy and breastfeeding, what a session actually feels like, driving and activity restrictions.