I did this for a psychology class. I no longer have the URL to the actual article, however I've summarized it in pretty good detail. I realize a lot of you already know a lot about DMT, but for those of you that aren't really sure how dangerous DMT is (according to actual research) this will be a great read for you. I've also responded to the risk assessment which most people find to be more interesting then the assessment itself. So if you're not really interested in reading the risk assessment, but would like to read a fellow psychonaut's views then skip to the last paragraph.
Note: I have left out my introduction which gives background information on DMT. I felt that would be a little unnecessary to include it here.
Robert S. Gable begins his review of risks involved in ritual use of oral DMT and harmala alkaloids by introducing a U.S. supreme court case that questioned the safety of ceremonial use of the DMT containing brew, ayahuasca, by members of a spiritually inclined Christian church. Although the government opposed and still does oppose the use of DMT, they were unable to demonstrate how the brew posed any serious health risks. The goal of this article is to review the known systematic health risks of oral DMT/ayahuasca consumption. Gable goes on to explain specifically what he means by the term risk. He defines it as the probability of future harm, and explains that the concept of risk is based on the relationship between a potential hazard and some unwanted outcome, such as illness. There has been very little scientific data about the oral use of DMT, and Gable explains his article will be taking a broad view of potential health risks, and he hopes future research will be able to better establish the true risks.
Next, Gable gives some background information on ayahuasca, and how such a brew allows the key molecule (DMT) to become active in the synapses of the brain. Ayahuasca is essentially composed of two compounds, DMT and a MAO (monoamine oxidase) inhibitor such as harmine, harmaline, or tetrahydroharmine. In a brew like ayahuasca, the DMT is only active in combination with an MAO inhibitor. If DMT is smoked, snuffed, or injected the MAO inhibitor is not needed. Ayahuasca is prepared by mixing leaves from the plant Psychotria viridis (The MAO inhibitor), with bark scraped from the stem of the (DMT containing) Banisteriopsis caapi vine. Typically there are a number of other ingredients, however these are the two essentials. The brew is boiled for several hours and the finished product is a thick, brown, oily substance. It's important to note that ayahuasca has been used (mostly in the Amazon) ceremonially for thousands of years. Today there is two primary church organizations, based in Brazil, that continue to use the brew as a religious sacrament. The largest is the "O Centro Espirita Beneficiente Uniao Do Vegetal", more commonly known as the UDV. The UDV was founded in 1961 and is estimated to have around 8000 members. The organization cultivates the required plants for ayahuasca on their own property. An ayahuasca preperation ceremony called "preparo" may involve hundreds of people and may spread over several days. In 1992 Brazil made it legal to use ayahuasca in a religious setting. This concludes the introductory section of the article.
Gable began his research by typing six key terms into six online databases. The terms were "ayahuasca", "hoasca", "dimethyltryptamine", "harmine", "harmaline", and "tetrahydroharmine." He scanned for the topics "overdose", "lethal dose", "toxicity", "death", "therapeutic index", "abuse potential", and "dependency". He also used relevant books, and journal articles. In order for a piece of information found in the search to be considered relevant, Gable says it must meet at least two of four criteria: 1. DMT or one of the MAO inhibitors was quantified with respect to an effective or toxic dose. 2. The health status of the individual had to be stated. 3. The possible use of other substances was mentioned, and 4. The data source needed to be technical or scholarly in nature. Gable found fewer than 100 relevant articles that were printed in English. The total number of documents and resources that met the requirements ended up being around 140. Gable goes on to discuss the weight of DMT and the MAO inhibitors which plays a role in the varying ayahuasca concentrations. He also explains the process in which UDV members test potency, and ingest the brew. He notes a distinct difference in taking ayahuasca and injecting/smoking/snuffing DMT. The former three are known for their rapid onset with peak experiences lasting only 3-10 minutes, and normal consciousness returning around 30 minutes. Ingesting ayahuasca can take about 20 minutes to feel onset effects, and peak effects usually last 1-2 hours, with normal consciousness returning after 4 hours. The effects of oral DMT use through ayahuasca have been noted to be less intense than the other three methods.
Gable explains that the median lethal dose of a substance (LD50) is the statistical dose of the substance that causes death in 50% of the experimental animals. The LD50 of DMT in mice was reported as 32mg/kg intravenously. There was no other LD50 data regarding DMT available in English. However there is LD50 data on similar compounds such as serotonin, which was 60mg/kg. The LD50 of harmine is reported as 2mg/kg, significantly lower than that of DMT. Gable decides to focus on DMT as the primary risk component in ayahuasca. Since we cannot transfer the lethal dose from rodents to humans, Gable explains how we must make some minor assumptions. Typically we assume humans are about ten times more sensative than rodents, so to be extra cautious, since there is no data for the LD50 of DMT (in humans), Gable assumes humans are twenty times more sensative than rodents. This makes the LD50 of IV DMT in humans 1.6mg/kg, or a total dose of 112 mg for your average 70kg person. Since we are accessing the toxicity of ayahuasca, Gable then converts the LD50 of IV DMT to an equal oral dose. After careful consideration of differences in effect between oral and IV DMT, he concludes that 8mg/kg or a total of 520mg would be a lethal dose of oral DMT in a 70kg person. He then compares the lethal dose to the typical dose of an ayahuasca ceremony which is about 27mg. The difference between a lethal dose and the average ceremonial dose is about 20mg, because 560/27=20.7.
According to the articles and data Gable found, there has been two primary health risks recorded. The first one is addressed as cardiac stress in the article. According to Rick Strassman's studies a 0.4mg/kg dose of IV DMT raised an individuals heartbeat approximately 26 beats per minute, 2 minutes after the injection. The same dose raised systolic pressure by 35mmHg and diastolic pressure by 30mmHg. In ayahuasca doses of 0.48mg/kg to 1mg/kg showed an increase in heart rate and blood pressure at about one third of the increase from IV DMT, 90-120 minutes after ingesting the brew. This is considered to be a minimal increase. A key finding here is that even though ayahuasca can increase heart rate and blood pressure, it seems to have less risk potential than many commonly abused psychoactive substances. Data from these reports is summarized in Table 2 of the article. It's important to realize that the individual taking the substance, their health, differences in metabolism, and the "set and setting" can contribute to a wide range of effects. The article uses Rick Strassman's research as an example. His IV DMT study showed the highest heart rate was around 150 BPM while some other participants heart rate didn't rise above 95 BPM. Gable notes that in ayahuasca the amount of DMT in relation to the amount of the MAO inhibitor may create differences in effects and even cause the heart rate to slow down. According to caffeine studies, a 150ml cup of instant coffee increases the heart rate more than twice as much as oral DMT does. Along with increased heart rate and blood pressure, Gable also mentions the possibility of undesirable effects such as, tremors, diarrhea, autonomic instability, hyperthermia, sweating, and muscle spasms. These are due to the MAO allowing a larger quantity of serotonin to accumulate in nerve terminals. There is also a possibility of severe toxic reactions to psychoactive tryptamines. There has been one reported death due to amine intoxication in a 25 year old man who had smoked 5-MeO-DMT and then took ayahuasca. When 5-MeO-DMT is smoked it is reported to be more potent than when DMT is taken with an MAO inhibitor. Table 3 in the article summarizes the few severe toxic reactions to ayahuasca and related compounds that have been reported.
The next major potential health risk is psychological damage. A medium dose of DMT in ayahuasca puts an individual into what is called a visionary state, where colors become more vibrant and objects begin to vibrate. This doesn't necessarily cause the individual to lose their sense of the surrounding environment. In experiments with with high doses people often reported the experience to be very dream like and the passing of time was heavily affected. People felt less judgmental, and more interconnected to every thing. In regards to time, people reported that time felt non existent and that they were experiencing "eternity". This is all associated with the common feeling of extreme awe and well being, but can also be replaced by feelings of terror. The ayahuasca experience almost always makes the individual seriously reflect on the miracle of life, and the nature of existence. UDV members claim the experience has had a profound, beneficial impact in their life. Gable notes similarities between the ayahuasca experience and characteristics of individuals with schizophrenia. A few researchers have found above average concentrations of DMT in the blood and urine of schizophrenics. Researchers have hypothesized that excessive DMT could lead to the deterioration of cognitive mental processes. Different studies have produced different results, which leaves this area still relatively unexplored. Ayahuasca can produce a wide range of psychological effects, which are dose dependant, especially in a non guided non ceremonial situation. There has been reported psychotic episodes with LSD, and psilocybin which are also tryptamine based psychoactive substances. Differences in potency between these substances makes it hard to relate potential psychological damage from LSD or psilocybin to potential damage from DMT. In a period of 5 years medical studies of the UDV reported between 13 and 24 cases where ayahuasca could have contributed to a psychotic episode. This is out of 25,000 servings of the brew. The UDV reported the rate of psychotic episodes is under 1% which implies the use ayahuasca is not a key role in sustained psychosis. Most incidents were reported to have been resolved with ease.
One of the most crucial concerns involved with any mind altering substance is the dependence and abuse potential. According to Gable there has been no convincing documentation that ayahuasca/DMT have a serious abuse potential. Other hallucinogenic substances similar in composition to DMT have been reported to rarely be used in a compulsive manner. According to tolerance studies by Rick Strassman the human body doesn't build tolerance to DMT quickly, and it is presumed to make little physiological change. There has been very little research specifically related to abuse potential of DMT. According to the UDV 15-20% of first time participants in an ayahuasca ceremony become UDV members, which doesn't seem very high to me. According to Gable the psychopharmocology of DMT suggests that it lacks the abuse rate other substances, such as cocaine or opiates have. Hopefully researchers can continue looking into this, and be able to better determine the true abuse potential of ayahuasca/DMT.
Gable closes his article by discussing his findings. He explains that there seems to be insufficient evidence for either side of the argument, and decisions have to be made regardless. He claims that according to current data, DMT appears to have a substantially less systematic toxicity than alcohol. The lethal dose of alcohol is around 10 times the average recreational dose, while with DMT it is at least 20 times the average dose. Some researchers have even suggested the lethal dose of DMT is 40-50 times higher than the average dose. Aside from the slim chance of a severe serotonin related reaction to DMT, there seems to be no acute health risks according to Gable's findings. Gable claims that all of the poisonous reports of tryptamine MAO inhibitor mixtures involved people who prepared their own brew, and often mixed it with other psychoactive substances. He goes on to explain how the amount of unwanted effects such as diarrhea and nausea make ayahuasca an unlikely candidate for a club drug, and thus has low abuse potential. Gable closes the article by stating his belief that variations of consciousness are worthy of serious study because of their place in human endeavors.
I found this article very interesting and informative. Although I'm familiar with much of the research that has been done with DMT, I learned some new interesting things. I wasn't aware how much more toxic legal substances, such as caffeine and alcohol, were compared to the toxicity of DMT. I was astounded that at out of 25,000 servings of ayahuasca over 5 years produced only up to 24 reported incidents of psychosis. This number was quite a bit lower than I might of suspected. As Gable found, there really hasn't been very much research done with this intriguing chemical. This makes me wonder why DMT was made illegal under the controlled substances in 1970. In 1970 there was even less research to support that DMT has no medical value, has significant health risks, as well as high abuse potential. The majority of in depth research has all been done within the past two decades. All the research we have today suggests that the health risks are significantly lower than legal substances that are widely abused by our society, as well as lower abuse potential than most drugs. So why is this chemical illegal, and why is it so hard to get government approval to continue researching the role of DMT in our bodies, as well as health risks and abuse potential? A nation that claims religious freedom has outlawed what more people than we realize consider to be a religious sacrament. This in turn creates crime, and fills our jails with religious individuals who were simply perusing their "religious freedom". Psychologically speaking, I feel DMT can offer great insight into the nature of consciousness and brain function. Scholars across the world agree with this statement, as do many of the individuals who have had a DMT experience. I feel like we could understand much more about our brains and psychology if we allowed ourselves to study chemicals like DMT. Lack of research in this and similar areas is propelling us into a spiral of ignorance about our own biological composition. To understand the makeup of the human brain allowes us to better understand the environment we live in, and our role in it. These are some of the largest, most important philosophical questions known to mankind, and our society has made it illegal to persue these questions through use of a chemical that our brain needs to function. I find it humorous that we're all in possession of an illegal drug, all the time, and I am deeply saddened to see so many intelligent people immediately dismiss DMT as "just another drug". From my own investigations (not experiences) it is so much more important than that. I hope papers like mine, and the article I read will continue to inform people about DMT, and motivate researchers to continue trying to get government approval for more research. With all the violence, and what I feel is obvious political corruption in our world today, I firmly believe it's time we start looking for something more important to live for. We all share the same emotions and life struggles, and I feel humanity is approaching a desperate need for unification. Recent studies with DMT, neuroscience, and quantum physics have shown significant evidence that we're all interconnected, and the need for new social models is here. It's time we face our old ways, and come together to create new ideals that fit with the newest discoveries of psychology and quantum physics. If we do not allow more research to be conducted, we may very well be stuck in the rut we're in now for many years to come.