Why does ayahuasca make you throw up? The pharmacology and spiritual significance of purging

October 7, 2025 •

4 min read

According to a 2022 survey involving over 10,000 ayahuasca users, nearly 70% reported experiencing acute physical adverse effects, primarily vomiting. Understanding why does ayahuasca make you throw up involves a blend of complex pharmacology and the deep spiritual significance of purging in traditional contexts.

Quick Summary

Ayahuasca purging, often involving vomiting, is caused by the interaction of its psychoactive compounds with the body's serotonin system, triggering the brain's vomiting center. This physical reaction is viewed in traditional cultures as a spiritual and emotional cleansing process.

Key Points

Monoamine Oxidase Inhibition: The Banisteriopsis caapi vine contains MAOIs that inhibit the enzyme which normally breaks down DMT, allowing the powerful psychedelic to become active in the body.
Serotonin Receptor Overload: Both DMT and the MAOIs flood the body's serotonin receptors in the brain and gut, causing nausea, vomiting, and other gastrointestinal distress.
Area Postrema Activation: The potent serotonin effects specifically stimulate the area postrema, the brain's vomiting center, triggering the forceful purging reflex.
A Deliberate Ritual Cleansing: In traditional Amazonian practices, vomiting (the 'purge') is not a side effect but a spiritually significant act of cleansing, releasing negative emotions and toxins.
Unpleasant Taste and Physical Toxicity: The bitter, intense flavor of the brew and the alkaloids themselves can also cause physical discomfort and contribute to the urge to vomit.
Integration of Body and Spirit: The purge highlights the indigenous belief that the physical body is deeply intertwined with emotional and spiritual well-being, with healing happening on multiple levels.

The Pharmacological Foundation of the Ayahuasca Purge

Ayahuasca is a potent brew typically made from two plants: the Banisteriopsis caapi vine and the leaves of the Psychotria viridis shrub. This combination is crucial because it facilitates the brew's profound effects and triggers the intense physical reaction known as 'the purge.' The process hinges on the interplay between two key psychoactive compounds.

The Role of DMT and MAOIs

N,N-Dimethyltryptamine (DMT): The Psychotria viridis leaves contain DMT, a powerful psychedelic. When taken orally by itself, DMT is quickly broken down by enzymes called monoamine oxidases (MAO) in the stomach and liver, preventing it from entering the bloodstream and reaching the brain.
Harmala Alkaloids (MAOIs): The Banisteriopsis caapi vine contains harmala alkaloids, including harmine and harmaline, which are monoamine oxidase inhibitors (MAOIs). These compounds temporarily inhibit the MAO enzymes, effectively blocking the breakdown of DMT. This allows the DMT to remain active, cross the blood-brain barrier, and produce its hallucinogenic effects.

Serotonin Receptor Stimulation and the Area Postrema

One of the main pharmacological reasons for nausea and vomiting is the effect of ayahuasca's compounds on the body's serotonin system. DMT is structurally similar to the neurotransmitter serotonin and acts as a potent serotonin agonist. This powerful stimulation affects multiple areas, including the gastrointestinal tract and a specific region of the brain.

The Gut-Brain Connection: The gastrointestinal tract contains a vast network of nerves, often called the 'gut's brain,' and is rich with serotonin receptors. The surge of serotonin and DMT activates these receptors, causing an increase in intestinal motility and a feeling of sickness.
Activation of the Area Postrema: A key part of the brainstem, known as the area postrema, or chemoreceptor trigger zone, is responsible for detecting toxins in the blood and triggering the vomiting reflex. The high levels of serotonergic activity triggered by ayahuasca powerfully stimulate the 5HT3 serotonin receptors in this area, initiating a forceful and often intense purging response.

Other Physiological Factors

Beyond the primary chemical reactions, other factors also contribute to the physical discomfort.

Alkaloid Toxicity: The harmala alkaloids themselves, particularly harmaline and harmine, are known to induce gastrointestinal distress, including nausea and vomiting, especially at higher doses. A 2024 study on pharmaceutical-grade harmine found that doses above a certain threshold consistently caused nausea and vomiting in healthy participants.
Taste and Texture: The brew itself is often described as having a strong, bitter, and unpleasant taste and texture. For some individuals, this sensory experience is enough to initiate a gag reflex and contribute to the overall nausea.

The Spiritual and Cultural Significance of the Purge

In the Amazonian traditions where ayahuasca originates, vomiting is not a negative side effect but a deliberate and purposeful part of the healing process. Known as 'la purga,' this act holds profound spiritual and cultural meaning for both indigenous and modern participants.

Spiritual Cleansing: Traditionally, the purge is viewed as a symbolic and literal cleansing of negative energy, spiritual intrusions, and emotional blockages. Shamans teach that the brew's intelligence helps to identify and expel physical toxins and metaphysical impurities built up within the body. The intensity of the purge is sometimes interpreted as a sign of the amount of negativity or trauma being released.
Emotional Release: The physical act of vomiting, crying, or other forms of purging are seen as an external expression of deep internal emotional release. Participants often report that the purge feels like letting go of built-up emotions like shame, anger, and fear. This cathartic experience can be a powerful catalyst for personal growth and emotional processing.
Connecting with the Spirit World: For many traditional users, the purge is a necessary step to connect with the spirit world and receive guidance. By expelling what is no longer needed, they can achieve a clearer state of mind, allowing for a more profound and insightful spiritual experience.

Scientific vs. Spiritual Explanations: A Comparison


Aspect	Scientific Perspective	Traditional/Spiritual Perspective
Cause	Activation of serotonin receptors in the gut and brain's vomiting center by alkaloids like DMT and harmine.	Expulsion of negative energy, trapped trauma, and spiritual toxins.
Purpose	A physiological, non-essential side effect of the psychoactive substances.	An essential, purposeful, and healing part of the ceremony—a form of deep cleansing.
Significance	Indicates the body's reaction to powerful alkaloids.	A rite of passage, a symbolic shedding of past burdens and blockages.
Response to Vomiting	To manage the physical discomfort, which is often considered unpleasant.	To surrender to the process and embrace the release, as it is considered vital for healing.
Mechanism	Chemical interaction, enzyme inhibition, and neuronal stimulation.	The intelligence of the plant medicine guiding the process to restore balance.

Conclusion

Understanding why does ayahuasca make you throw up requires acknowledging both the rigorous pharmacological mechanisms and the rich cultural context of its use. While science clearly explains the physiological basis through the action of MAOIs and DMT on the body's serotonin system, this purely biological view misses the profound, intentional role of purging within the ceremonial setting. In traditional practices, the act of expelling is viewed as a necessary and deeply significant cleansing process—a physical and spiritual catharsis essential for healing and connection. Both perspectives offer valid insights into this complex and powerful phenomenon, highlighting the unique interplay between human biology and spiritual experience in the context of plant medicine.

For those interested in the scientific research surrounding the therapeutic potential of ayahuasca, the National Institutes of Health provides numerous resources on psychedelic medicine.(https://pmc.ncbi.nlm.nih.gov/articles/PMC6007657/)

Frequently Asked Questions

Yes, vomiting is a very common and expected part of an ayahuasca ceremony, and it's even referred to as 'the purge.' Most experienced participants view it as a normal and beneficial part of the experience.

In many traditional contexts, purging is seen as a physical and spiritual cleansing. It is believed to represent the release of negative energy, emotional trauma, and physical toxins, making way for healing and new insights.

While a pre-ceremony dietary restriction ('dieta') is designed to reduce physical discomfort, it is not recommended to suppress the urge to purge. Attempting to do so may interfere with the intended healing process.

Yes, purging can manifest in many different ways, including diarrhea, crying, yawning, sweating, and shaking. Each form is considered a valid expression of release and cleansing.

Not everyone experiences the purge in the same way. The intensity of the reaction can vary based on the individual's body chemistry, the specific brew composition, and their personal emotional state. Some may experience subtler forms of release like yawning or crying.

In a controlled ceremonial setting with an experienced practitioner, the purge is typically not a sign of harm and is considered a normal, though intense, process. However, severe or prolonged adverse effects that require medical attention are possible in some cases.

The compounds in ayahuasca, particularly DMT and the harmala alkaloids, significantly increase serotonin activity in both the brain and the gut. This overstimulation of serotonin receptors triggers the nausea and vomiting response.