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Side Effects of Ketamine: What to Know

A woman experiencing ketamine therapy

Ketamine is a powerful medication and psychedelic utilized for mental health symptoms such as depression, suicidal ideation, stuck thoughts, and anxiety. One of the most common questions asked are about the side effects of ketamine. Traditionally, ketamine has been used for pain management in emergency departments and in operating rooms. In the early 2000's, it was found to be particularly safe and effective for depression. Since then, its use has increased significantly.

Most Common Ketamine Side Effects

The most common side effects of ketamine include nausea and vomiting. The chances of the side effects is lessened when patients abstain from eating or drinking in the 3-4 hours before their ketamine journey. Offerings such as ginger chews, acupressure bracelets for motion sickness, and anti-nausea medication like ondansetron or Zofran, can also be helpful. Nausea is most likely to occur as someone is returning from their journey and move too quickly from laying down to sitting, and then to standing.

Dizziness and feelings of disorientation are also common experiences one can expect as part of their ketamine journey. These effects will fade within an hour or two of the ketamine session.

During a ketamine session, it is typical for blood pressure to also increase moderately. This is why blood pressure is typically checked at least before the session. Additionally, when ketamine is administered individuals may also start feeling their heart beat a little faster. This can understandably amplify any anxiety about embarking on a new experience such as ketamine but it can be reassuring to know about this beforehand.

Less Common Ketamine Side Effects

The less common side effects of ketamine include bladder issues, known as ketamine-induced cystitis. The exact pathophysiology is unknown but thought be be due to inflammation triggered by ketamine. This leads to symptoms such as frequent urination, urgency, pain during urination, and blood in the urine. Dose and frequency matters here. Urinary symptoms can be seen in over 25% of recreational users of ketamine, which has been directly correlated with dose and frequency of use. The likelihood of ketamine-induced cystitis is very low if not used on a regular basis (which I would define as 2-3 times a week).

Though rare, some individuals might experience allergic reactions to ketamine, including rash, itching, swelling, or in severe cases, anaphylaxis.

Not Side Effects of Ketamine

People will also experience changes in perception but when utilized in a therapeutic setting (i.e. ketamine assisted therapy), we don't consider these side effects - which have a negative connotation, but rather, worthy of curiosity and a jumping off point for further exploration.

As with any medication or treatment option, there are risks and benefits. From a psychedelic perspective, ketamine is generally well-tolerated and has a more favorable side effect profile than other psychedelic medicines.


Interested in ketamine assisted therapy? Learn more about becoming a patient here.

A kind reminder: This blog post is designed as a general guide. This is not a substitute for personalized medical advice, nor is a patient-physician relationship established in this blog post.


Read more psychiatrist-written blog posts about ketamine assisted therapy:


Winstock AR, Mitcheson L, Gillatt DA, Cottrell AM. The prevalence and natural history of urinary symptoms among recreational ketamine users. BJU Int. 2012;110(11):1762-1766. doi:10.1111/j.1464-410x.2012.11028.x


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