It doesn’t need to be, there is reasonable proof that humans and other mammals naturally synthesises (trace amounts off) dmt, which are presumed to be used and broken down incredibly quickly. We still don’t know why, what its used for or have hard proof where its produced (pineal gland is main suspect for having all ingredients in theory)

In theory something could trigger an effect that stops it from breaking down or produce it at a faster rate, therefore triggering psychedelics effects with out the consumed substance containing anything psychedelic itself.

Dmt is known for seeing (machine) elves, does not sound that far away from seeing mini people.