Ketamine therapy is generally well tolerated when it’s prescribed after a careful medical evaluation, dosed conservatively and supported by trained people. It still carries real risks, from short-lived blood pressure spikes to misuse, and some people shouldn’t take it at all. This guide explains both sides.
We wrote it for anyone considering ketamine-assisted psychotherapy (KAP), and for the partners and parents who worry on their behalf. You’ll find the common side effects, the rarer long-term concerns, what the FDA and other bodies have said, the health conditions and medications that matter, and exactly how SomaVerse screens and monitors clients in our Lawrence, Overland Park and Topeka offices, and at home for those approved after completing our main program.
Nothing here replaces a conversation with a medical provider who knows your history. If you’re in crisis right now, call or text 988. SomaVerse is not an emergency service.
You might be here because…
- You’ve heard ketamine described as both a party drug and a breakthrough, and you want to know which is true.
- You have high blood pressure, a heart condition or another health issue and wonder whether you’d qualify.
- You take an antidepressant, a benzodiazepine or a mood stabilizer and want to know about interactions.
- Someone you love is starting ketamine therapy and you want to understand the risks.
- You read about the FDA warning on compounded ketamine and want it explained plainly.
- You’ve struggled with alcohol or other substances and want an honest answer about whether ketamine is a good idea.
The short answer: well tolerated for many, never risk-free
At the low, sub-anesthetic doses used in therapy, most side effects are mild and fade within a few hours. A large review of ketamine studies in depression found psychiatric, cardiovascular and neurological side effects were more common than with placebo, but usually brief. The same review noted that long-term safety data on repeated dosing are still limited.
Ketamine has been used as an anesthetic for more than half a century and is on the World Health Organization’s list of essential medicines, as an anesthetic. That long history is reassuring, but surgery doses in a hospital and repeated therapy doses over weeks are different situations. Safety in therapy comes from who takes it, how much, how often, and who is watching.
Common ketamine side effects, and how long they last
Most side effects show up during the session and settle as the medicine wears off, usually within one to two hours, with some tiredness lingering for the rest of the day. Troches are absorbed more slowly than IV ketamine or nasal sprays, so effects tend to build more gradually; see troches vs. IV vs. Spravato for how routes compare.
- Blood pressure and heart rate rise, typically peaking within the first hour. This is the main reason we screen for hypertension and heart disease.
- Nausea, occasionally vomiting. A light stomach helps, and anti-nausea options can be discussed with your medical provider.
- Dizziness and unsteadiness. Stay seated or lying down, and get up slowly with help.
- Dissociation: feeling detached from your body, surroundings or sense of time. In KAP this is expected, and your preparation covers it.
- Headache, blurred or double vision, and drowsiness, which usually pass within hours.
- Anxiety or emotional intensity during the session, especially if difficult material surfaces.
Rarer and longer-term risks: bladder, memory and misuse
The most serious physical harm linked to ketamine is damage to the bladder and urinary tract, including painful, shrunken bladders. A major review by Morgan and Curran found this mainly in people using ketamine recreationally, often daily and in large amounts. Therapeutic courses are far smaller, but tell us right away about any burning, urgency, frequency or blood in your urine.
Frequent heavy use has also been linked to memory problems, and many frequent recreational users report trouble stopping. Ketamine has real abuse potential. The DEA placed it in Schedule III of the Controlled Substances Act in 1999, meaning it has accepted medical uses and a moderate risk of dependence.
Taking more than prescribed carries its own danger. Medical journals have described an unintentional overdose involving a telehealth ketamine prescription. That’s why dose limits, secure storage and a sober person with you matter, especially at home.
What the FDA, WHO and ketamine specialists say
FDA: ketamine is approved only as an anesthetic. Using it for depression, anxiety or PTSD is off-label, and compounded troches have not been evaluated by the FDA for safety, effectiveness or quality. In October 2023, the FDA warned about compounded ketamine, including oral forms used at home for psychiatric conditions, because no provider is on site to watch for sedation, dissociation or blood pressure changes.
WHO: ketamine appears on the WHO Model List of Essential Medicines as an injectable anesthetic. It is not listed for any psychiatric use, so be wary of anyone who implies otherwise.
Ketamine specialists: the American Society of Ketamine Physicians, Psychotherapists and Practitioners (ASKP3) published at-home guidance in 2024. It favors supervised settings, but accepts that oral or sublingual ketamine may be appropriate at home with an in-person risk assessment, a responsible adult present, no driving for the rest of the day, start-low dosing, only as much medicine as needed between visits, and safe storage. We built our protocol around those recommendations.
Medications and substances that matter
Ketamine is broken down mainly by liver enzymes (CYP3A and CYP2B6), and it adds to the effects of other drugs that slow the brain. That means your full medication list matters, including supplements and anything you take only now and then.
Tell us about every medication. Never stop or change a prescription on your own to prepare for ketamine; our medical provider will plan any timing changes with you and, when needed, with your prescriber.
- Benzodiazepines (such as lorazepam or clonazepam) and lamotrigine can blunt ketamine’s effects.
- Alcohol, opioids, sleep medications and other sedatives add to sedation and can slow breathing. Don’t combine them with a dose.
- Stimulants and some decongestants can push heart rate and blood pressure higher.
- Cannabis and other substances can make the experience less predictable and should be avoided around sessions.
- Most common antidepressants can usually be continued, but your provider will review them individually.
How SomaVerse screens and monitors every client
Safety starts before your first dose. Every client completes a pre-treatment medical assessment and a therapy assessment, and our medical team, led by our Psychiatry & Ketamine Medical Director, Angel Patterson-Tetuan, PMHNP-BC, decides whether ketamine is appropriate. Your first medical evaluation may be in person or by secure video, depending on current DEA and state rules. You’ll go through informed consent that covers off-label use, compounding and the FDA warning in plain language.
During treatment, there is medical oversight before, during and after sessions. We hold strict contraindications, such as uncontrolled high blood pressure and psychosis. Everyone starts in office, where a therapist or trained guide stays with you and checks vital signs. Joseph (Valentine) Dee, EMT, our Ketamine Medical Support, has assisted in more than 1,000 ketamine sessions and supports preparation, sessions and integration. At-home sessions are an option only after you’ve completed at least our main program and are medically approved; then a sober support person must be present, you receive only the doses planned between visits, and you agree to store them securely and not drive for the rest of the day. A medical check-in follows every dose.
If ketamine isn’t safe for you right now, we’ll tell you and help you find another path. Read more about supported at-home ketamine therapy, in-office sessions and our care team.
