Exploring Psilocybin from a medical perspective

To work safely with psychedelics, it is important to understand fully the potential side effects associated with the substance you are ingesting, and to undergo a thorough mental and physical health risk assessment to reduce the risk of harm.

As we take a look at psilocybin (the active ingredient of magic mushrooms) through a medical lens, it is first important to acknowledge that psilocybin is considered very safe, having the lowest profile of risk according to the Global Drug Survey and accounting for only 0.2% of Emergency Department visits in the US. When evaluating any negative effects from working with psilocybin, hold in mind the risk/benefit ratio from the illness with which the person is suffering. A person who has had chronic debilitating depression for much of their life, or suicidality, is no doubt in extreme mental anguish, and alleviation of their pain through working with psilocybin may be deemed worth the risk of potential side effects. Context is key.

Psilocybin, which has a duration of action of around 5-6 hours is considered a less exhausting psychedelic to work with than LSD, which has a duration of action of around 10-12 hours. LSD has been referred to as the “atomic bomb” of the psychedelic world, while psilocybin is more of a “weapon of conventional strength”. When working with patients in a palliative care setting for example, who are physically very ill, they would probably not have the strength to endure LSD. 

Most importantly in any discussion around working with psychedelics, is know what you are taking, and give due care and attention to having a safe set and setting.  

Set refers to the mindset with which you enter a psychedelic experience; take time to ground yourself, prepare, set intentions, sleep well, prepare your body and mind, nurture yourself. The psychedelic experience begins the moment you decide to go ahead with it, as your conscious and unconscious mind makes plans. Honour this. Be mindful of what you are reading, watching and inputting. Spend time with people who love you and treat you well.  

Setting refers to the environment you are in for the experience; ideally it will feel secure, calm, nurturing, have elements from the natural world, ceremony, music, intention setting, rituals of connection to yourself and your guides. Choose sitters who you trust. When you return home after your experience it is a good idea to create a similar safe space to land and ground, before facing the world fully. Many difficult psychedelic experiences can be prevented with a safe set and setting. 

Psilocybin is a serotonergic agonist targeting the 5-HT2A receptors found in the central nervous system and the gastrointestinal tract. Serotonin is known as the “happy hormone” found in SSRI antidepressants like fluoxetine (prozac), and so some of the physical side effects of psilocybin are similar to those experienced when taking these antidepressant medications. Serotonin makes us feel good, modulates our thinking, learning and memory. It creates feelings of happiness and reward. As 90% of serotonin receptors are in the gastrointestinal tract, side effects from psilocybin can include nausea, diarrhoea and constipation.

Physiologically, serotonin can cause both blood vessel constriction (vasoconstriction) and blood vessel dilation (vasodilation), causing either an increase or decrease in blood pressure. Rarely, stimulation of the 5-HT2A receptor through psilocybin use can cause coronary artery spasm. Psilocybin has been shown increase a person’s blood pressure (BP) an average of 10mmHg. This means a person who has healthy BP of 130/80 may be expected to increase to 140/90. This increase is marginal and probably not dissimilar to “white coat syndrome”, the increase in BP that can commonly be experienced due to anxiety during a trip to the doctor’s office. However, with someone who has a very high baseline BP, this increase may send them into a crisis. Getting a routine BP check before taking psilocybin is a really good idea. 

Psychologically, a person may experience visual disturbances, troubling thoughts, paranoia, panic and mild anxiety when taking psilocybin. They may have hyperawareness of their bodily processes, feeling their heartbeat intensely for example, or feeling their blood flowing. Fear and paranoid delusions can potentially lead to aggressive behaviours towards self and others. That being said, side effects are generally minimal and are more likely influenced by a poor set and setting, and the person’s emotional state. From a research study performed by John Hopkins University, it was found that from a cohort of 1193 participants, only 2.1 percent described having a “bad trip”. A difficult trip should not be written off as a failure, because even difficult experiences can hold significant meaning when integrated properly. 

From the Human Hallucinogen Research Guidelines for Safety, potential exclusions for people to work with psilocybin may include: 

Individual assessment of a participant by a competent practitioner is important when assessing psychiatric history, especially personality disorders. There are different opinions as to what client groups should be excluded from working with psilocybin. Ultimately this work could change a person’s life forever, so immediately excluding them can seem harsh. Professional opinion varies and sits with the individual practitioner.

Prolonged trips and acute psychosis from hallucinogens that can last for days or months, is a possibility, although rare. Mostly this has been reported through recreational LSD use, and is minimised in a clinical trial setting. Psychedelic integration psychotherapy, support groups and having a safe person to talk to about your experience, can minimise the harm from prolonged hallucinations. Often, prolonged hallucinations can give a person positive meaning, understanding and new insights about their life, when held and explored safely with a psychotherapist specialising in psychedelics.