The History of Mind Altering Substances in Humanity
Long, long ago, in a land before cars, airplanes, computers, cell phones and Twitter, humans used to live a bit more rustically. These primitive roots are not separate from any of us, as ancient civilization and native history is like the soil planted underneath every culture surviving today. Similarly, the history of psychedelics reaches far back into our culture -over thousands of years, spanning past old Eastern religions, early Mexican tribes, ancient Greece, early North America, South America, Africa. Evidence of psychedelics dates back to even early neolithic humans, according to The Essential Psychedelic Guide.  Psychedelics is a term derived from ancient Greece meaning, “mind-manifesting.”
A more suitable term in the context of human transformation is entheogen which is defined in Spirituality Health as “substances that generate the experience of God within.” 
Spiritual seekers and shamans of ancient cultures have used entheogens or sacred plants for healing, visionary guidance and mystical experiences. Generally speaking, politics in the 70’s revived entheogen use in the U.S. and the government stamped these substances as “drugs” or as misused recreational items, giving mushrooms, DMT, peyote, salvia divinorum, ayuhuasca, marijuana, and many more substances, a negative connotation. But after forty years of today’s modern research, advances of medical science are expanding a new and old understanding of psychedelics. Scientific instruments can now peer into its neurobiological affects, opening the conversation for entheogens to be used in humanity for healing all over again.  Here is an excerpt in Nature Reviews Neuroscience on the effects of psychedelics:
After a pause of nearly 40 years in research into the effects of psychedelic drugs, recent advances in our understanding of the neurobiology of psychedelics, such as lysergic acid diethylamide (LSD), psilocybin and ketamine have led to renewed interest in the clinical potential of psychedelics in the treatment of various psychiatric disorders. Recent behavioural and neuroimaging data show that psychedelics modulate neural circuits that have been implicated in mood and affective disorders, and can reduce the clinical symptoms of these disorders. These findings raise the possibility that research into psychedelics might identify novel therapeutic mechanisms and approaches that are based on glutamate-driven neuroplasticity.
Here is a list of popular entheogen substances that are gleaming with new and interesting research today.
Added Disclaimer: This article was written for informational purposes only and there are health risks surrounding each substance mentioned. Some substances are also considered illegal.
1. Magic Mushrooms
Or psilocybin, the mushroom-derived hallucinogen widely known for kicking off some major spiritual states of transformation within a person. Psilocybin has been said to have the ability to alter how one perceives and experiences the world. New studies and research is beginning to see how the brain is positively effected by its use.
For example, studies from Johns Hopkins School of Medicine published in Time Magazine revealed that just the right amount of psilocybin use can bring transcendental experiences. Volunteers experienced “long lasting psychological growth and helped people find peace in their lives – without the negative effects.” 
Or marijuana. There’s been a hefty controversial battle on the effects of cannibas, a genus of flowering plant used for hemp and medicinal aid. Cannabis has been used as medicine in China, India, the Middle East, and all over the world for thousands of years, according to BBC News.  Products like Hemp Backpacks also come from the plant.
Web MD features the side backs on this substance which is important to acknowledge.  But this is also a fact, that U.S. laws are allowing cannabis to be used medically as well as recreationally. In 1996, California passed Proposition 215, allowing the use of medical marijuana.  The Institute of Medicine published a report in response, that addressed the therapeutic effects of cannibas in a balanced light:
Scientific data indicate the potential therapeutic value of cannabinoid drugs, primarily THC, for pain relief, control of nausea and vomiting, and appetite stimulation; smoked marijuana, however, is a crude THC delivery system that also delivers harmful substances. The psychological effects of cannabinoids, such as anxiety reduction, sedation, and euphoria can influence their potential therapeutic value. Those effects are potentially undesirable for certain patients and situations and beneficial for others. In addition, psychological effects can complicate the interpretation of other aspects of the drug’s effect.
Or N, N-dimethyltryptamine. DMT is a highly powerful psychedelic, plant-derived, that dramatically affects human consciousness. DMT has been used in ancient South American tribes. It is a naturally occurring chemical found in human beings, activated upon sleep and in death. Its discovery is linked to Oswaldo Goncalves de Lima (1908-1989) who isolated an alkaloid from the root bark of Mimosa tenuiflora. Terrance McKenna popularized DMT in the 90’s.
Another leading resource on DMT is Rick Strassman, M.D., who heavily performed funded researched and studies on DMT at the University of New Mexico; he wrote the book DMT: The Spirit Molecule from these studies. 
Amazonian shamans have used ayahuasca for centuries as a way to peer into the soul. People still practice ayahuasca ancient rituals today to induce enlightening, transformative experiences.
Those who have taken ayahuasca have reportedly undergone extraordinary, life-changing visions as well as permanent healing. There is no going back with ayahuasca, it seems. This writer, Kira Salak, shared her experience in Peru in National Geographic Adventure Magazine with a long description on her experience, additionally sharing information on what it does. 
Salak writes in her article:
Most ayahuasca researchers agree that, curiously, the compound appears to affect people on three different levels—the physical, psychological, and spiritual—complicating efforts to definitively catalog its effects, let alone explain specific therapeutic benefits.
Additionally, Ralph Metzner, a psychologist, ayahuasca researcher, and editor of the book Sacred Vine of Spirits says:
[Healing with ayahuasca] presumes a completely different understanding of illness and medicine than what we are accustomed to in the West. But even from the point of view of Western medicine and psychotherapy it is clear that remarkable physical healings and resolutions of psychological difficulties can occur with this medicine.
Sources Used for this Article
 Time Magazine
 Web MD
 Rick Strassman
 BBC News