I know this topic is as old as dirt, especially in the Nexian sphere, but it is something that I think about every day and would like your input.
I am always wondering if the DMT experience is a real doorway to another dimension, or is it simply a hallucination.
Let me tell you why I think it is simply a hallucination: because I always only experience symbols and themes according to what I have been studying at the time. First, it was Eastern philosophy, so I saw Buddhas, and the entities I met were Buddha shaped and taught me Eastern philosophical lessons. Then it was Hinduism, where I saw Hindu Gods and thousand armed entities and the like. Next, after looking at a series of nude photos, I saw the clouds having an orgy that would make the Romans proud, the best adult video ever made. I even contacted my dead friend by sitting in the exact spot where he died, by intention. Then it was Native American culture, where I then saw teepees, fires, drumming, etc. Lastly, I contemplated and tried Christian thought, and saw angels, demons, and a God above the clouds.
The experiences seem to always be theme oriented according to what I am learning about at the time. Intention. Though this only happens on the lower end of high doses, because on the high end of high doses, everything is completely alien and beyond dreams, imagination, and anything which resembles Earth. I would like to believe that the experiences are outside of my brain, but I am just not that gullible.
I know we can never know for 100% sure, that it does take faith like anything else metaphysical, but I would like to know any ways or procedures that could prove this other dimension besides higher-dimensional mathematics, which is also based on some degree of faith.
Meditate before you venture, take it seriously, use it as medicinal—it is good psychotherapy if needed. Realize that you, the Earth, others, and the Universe are all one and the same process. Then take that knowledge back to become, as you already are, one with nature. Eternity in every moment. Divinity in every particle. All is one organism.