What are Contraindications?

Medically reviewed by 
Kristin Arden, PMHNP-BC
Published on 
April 30, 2021
Updated on 

Contraindication is a term that arises throughout the course of psychedelic therapy a fair bit, particularly during the intake process, and for good reason. Over and above individual healing and client outcomes, client safety is always the number one priority of a trained practitioner.

These experiences are designed to facilitate healing, and it is counterproductive to embark on a healing journey that has the potential to do more harm than good. Contraindications are one of the ways that practitioners ensure client safety, and make sure that the right people are embarking on experiences best suited for them, their circumstances, and their healing goals.

Defining Contraindication

A contraindication is any specific drug, procedure, or medical condition that demonstrates that it is not safe or advised for a particular individual to move forward with a particular treatment. In other words, they are warning signs that if an individual has a contraindication for a particular medical treatment, it is inadvisable, and potentially dangerous, if they continue moving forward with that treatment.

There are two levels of contraindication: relative and absolute.

Relative contraindication

A relative contraindication means that the client and care team should exercise caution when moving forward with the protocols of choice, as the potential exists for some negative interaction.

Combining certain types of medications, for example, can be a relative contraindication. If the individual and care team feel that the benefits most likely will outweigh the potential risk, then they can move forward with the treatment plan.

Absolute contraindication

An absolute contraindication means that the client and care team should not move forward with the potential treatment protocol as it is likely this will cause more harm than good, and in some cases can be life-threatening.

An absolute contraindication should be a hard stop for individuals and care teams if they become aware that a serious contraindication exists.

Psychological and physiological contraindications

Though contraindications are often noted as a complete group, you can further segment these by psychological contraindications, and physiological contraindications.

Psychological Contraindications

These are contraindications relating to the individuals mental state and overall psychological health. Examples of potential psychological contraindications can include things such as suicidal ideation, schizophrenia, or active mania or hypomania as seen in bi-polar personality disorder.

Physiological Contraindications

These are contraindications relating to the individual's biology and physical state. Examples of potential physiological contraindications can include medical history such as high blood pressure, abnormal heart rate, certain kinds of medications, pregnancy, or glaucoma.

Honouring contraindications is done for two specific reasons: to prevent and mitigate both short-term acute, and long-term enduring adverse events or reactions to the experiences. There can be acute impacts such as bodily discomfort, nausea, abnormal heart/breathing rates, or fainting/death. These also help mitigate long-term adverse reactions such as depersonalization, manic or psychotic, depression and/or suicidal behaviour, etc.

Fortunately, if practitioners honor and respect the specific contraindications for each medication and experience, psychedelic medicines and psychedelic therapy can be well-tolerated, safe, and effective experiences for healing. If a person is physically and mentally able to receive the medicine, these experiences have only a minor body load, and hopefully do more healing than harm for whatever it is the individual is working through.

As always, whenever you are in doubt or would like a second opinion, share openly and honestly with your care team, and seek second opinions so that you are making the best decisions for your health and your healing journey.

Body Load and the LD50

On the whole, most compounds used in psychedelic therapy do not have an extreme body load —the overall impact directly on the body, when compared to other recreational drugs or certain medications.

There are many other compounds, such as alcohol, tobacco, caffeine, or some pharmaceutical medications that have a much more direct and pronounced effect on the body. These effects can lead to illness, debilitation, or death if ingested in too great amounts too quickly.

A reference point here is what is known as the LD-50: the amount of the compound that would serve as a lethal dose for 50% of the general population. Many classical psychedelics (psilocybin, LSD) have very high LD-50’s and it would prove very difficult for an individual to reach a physically lethal dose. In comparison, caffeine and nicotine are much more acute and have lower LD-50’s.

Although the compounds themselves are often handled reasonably well by a large portion of individuals, this is not the only basis for a contraindication. As psychedelic compounds work on the mind as well as the body, it is important to take this full picture into consideration. There are some physiological concerns, particularly around heart rate, and blood pressure alongside contraindications concerning mental health.

Psychedelic Therapy Contraindications

Psychedelic therapy can be healing for individuals, but it can also be challenging for some and end up causing more harm than healing. This is why the medical screening and intake process is so important, so that you arrive at safe and effective healing protocols for each individual. A major part of the medical screening process is to look for contraindications.

As psychedelic therapy involves the use of certain medicinal compounds, there are both psychological and physiological contraindications that must be screened out. These contraindications can cause serious long-term damage if not acknowledged before going into a psychedelic experience.

This list is not exhaustive and should not be taken as medical advice, always seek the input of a trained and licensed practitioner before working with these experiences.

Examples of possible psychological contraindications for psychedelic therapy include:

  • Personal history of schizophrenia, bipolar disorder, or severe depression
  • Family medical history of schizophrenia, bipolar disorder, or severe depression
  • Active suicidal ideation or previous attempts
  • Major emotional dysregulation

Examples of possible physiological contraindications for psychedelic therapy include:

  • Actively taking certain medications like SSRI or MAOI, and the specific dosages
  • Very high or very low blood pressure
  • Heart arrhythmia or irregular heart beat
  • Personal or family history of epilepsy/seizures

It is important to discuss these contraindications with your practitioners and care team, so that everyone is fully aware of the situation, and that the best plan of care can be made for each individual. Some practitioners and therapeutic experiences are better able to handle particular instances, and a personalized program can be created to serve these unique cases.

Ketamine Therapy Contraindications

Much like any other medical compound and psychedelic medicine, ketamine has its own list of associated contraindications that are important to honor to ensure client safety. There are many similarities with the previous psychedelic therapy contraindication list, and a few other considerations given the mechanisms of action and the particular body load that comes with ketamine ingestion.

Possible psychological contraindications of ketamine include:

  • Personal or family history of schizophrenia, manic and hypomanic bi-polar disorder
  • Active suicidal ideation, previous attempts
  • Psychosis and major emotional disregulation

Physiological contraindications of ketamine include:

  • Very low or high heart rate
  • Very low or high blood pressure
  • Personal/family history of epilepsy/seizures

What If I Am Contraindicated?

You may be reading this and notice that there may be a point or two here that could apply to you. This is alright, getting appropriate information is always the first step.

If you believe that you may be contraindicated for psychedelic therapy or ketamine treatment, it’s always important to speak to your primary care provider and with the practitioners / clinicians administering the medicine / experience. This is not something that you can or should try to determine on your own. Work alongside the trained and experienced practitioners that are here to support you and provide the best possible healing protocols for your growth and wellbeing.

If you think you have a contraindication, you can do the following:

Contact your practitioner and tell them

Safety is always the number one priority. Specific contraindications exist to ensure your safety and prevent further harm from these treatments. They should not be taken lightly or overlooked. If you have any concerns or questions, contact your care team and open a discussion.

Share all relevant information

All information is helpful, it is never a bad idea to share as much as possible with your care team. It helps them to make the most informed and effective decisions possible. Some practitioners are more comfortable working with certain symptoms than others, so giving them the full picture will be helpful.

Address them with care

As mentioned above, some contraindications may only be relative contraindications, meaning you and your care team can make an informed decision, look at all the options, and make a decision to move forward.

Some contraindications can be managed or mitigated, such as working with your care team to wean off of SSRI medication if they are contraindicated. Never do this by yourself, always do this under the supervision of clinical staff. However, you can work with your practitioners to effectively manage and mitigate any relative contraindications. If they are absolute contraindications, see the next section.

Find the appropriate medicine

If you have an absolute contraindication for a certain medicine or type of experience, that just means that this avenue may not be best suited for you at this time.

Despite a potential interest in psychedelic therapy, doing this work with a contraindication can severely aggravate the condition, or do much more harm than good. Working with trained professionals to find the experience that is suited for you will do far greater than trying to force your way into a potentially dangerous situation.

Differences in Medicines/Experiences

This is a broad overview and introduction into contraindications found in psychedelic therapy and ketamine treatment. It is not possible to summarize all the contraindications for all medicines, as some medicines are able to work with contraindications that others are not.

For example, ketamine works on a different system in the brain, working with the glutamate instead of the serotonergic system. As a result, it is better able to work with clients actively taking SSRI medications.

Each medicine and each therapeutic experience will come with its own personal list of contraindications, so if you are contraindicated for one medicine, you may be able to find other medicines or other experiences that are better able to serve those specific symptoms.

Whenever you are considering any form of new experience that works on your mind and body, from meditation, to breathwork, to psychedelic therapy,  it’s important to look up the associated contraindications. Yes, even contemplative or embodied practices such as yoga, meditation, and breathwork have specific contraindications.


Contraindications are established and response protocols for them are enacted for client safety, to ensure that these remain spaces and experiences for healing and not for harm. They are not to be taken lightly, and you should work alongside trained professionals to help determine the best course of action for yourself.

However, by sharing any questions or concerns, by consulting the trained experts you are working with, you can determine the best course of action for you, personalize your programs so they fit with your unique circumstances, and move forward on your journey of healing and wholeness.


This article is for informational purposes only and is not intended to be a substitute for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. If you are in a life-threatening situation, call the National Suicide Prevention Line at +1 (800) 273-8255, call 911, or go to the nearest emergency room.

Important FDA Safety Information

Ketamine is not FDA-approved for the treatment of depression or anxiety. Learn more about off-label uses here.

Side effects of ketamine treatment may include: altered sense of time, anxiety, blurred vision, diminished ability to see/hear/feel, dry mouth, elevated blood pressure or heart rate, elevated intraocular or intracranial pressure, excitability, loss of appetite, mental confusion, nausea/vomiting, nystagmus (rapid eye movements), restlessness, slurred speech, synesthesia (a mingling of the senses).

Do not proceed with ketamine treatment if any of the following apply to you:

  • Allergic to ketamine
  • Symptoms of psychosis or mania
  • Uncontrolled high blood pressure
  • CHF or other serious heart problem
  • Severe breathing problem
  • History of elevated intraocular or intracranial pressure
  • History of hyperthyroidism
  • Other serious medical illness
  • Pregnant, nursing, or trying to become pregnant

Ketamine has been reported to produce issues including, but not limited to, those listed below. However, lasting adverse side-effects are rare when medical protocols are carefully followed.

While ketamine has not been shown to be physically addictive, it has been shown to cause moderate psychological dependency in some recreational users.

  • In rare cases, frequent, heavy users have reported increased frequency of urination, urinary incontinence, pain urinating, passing blood in the urine, or reduced bladder size
  • Ketamine may worsen problems in people with schizophrenia, severe personality disorders, or other serious mental disorders.
  • Users with a personal or family history of psychosis should be cautious using any psychoactive substance, including ketamine, and discuss potential risks with your MindBloom® clinician before proceeding with treatment.
  • The dissociative effects of ketamine may increase patient vulnerability and the risk of accidents.

To promote positive outcomes and ensure safety, follow these ketamine treatment guidelines:

  • Do not operate a vehicle (e.g., car, motorcycle, bicycle) or heavy machinery following treatment until you’ve had a full night of sleep
  • Refrain from taking benzodiazepines or stimulants for 24 hours prior to treatment
  • Continue to take antihypertensive medication as prescribed
  • Avoid hangovers or alcohol intake
  • Refrain from consuming solid foods within 3 hours prior to treatment and liquids within 1 hour prior to treatment
  • Ketamine treatment should never be conducted without a monitor present to ensure your safety

Questions? Chat With an Exploratory Guide

Take our brief assessment, and speak with an expert who will help ensure psychedelic treatment matches your goals.

Take the AssessmentTake the Assessment