I once ate 10 mg LSD by accident. It was a dilution error. The peak lasted ~10 hr. At some point, I saw the top of my head. But hey, maybe it was just an hallucination ;)
https://www.shroomery.org/forums/showflat.php/Cat/0/Number/1...
Also, reading about a few NDEs, they sound quite similar to a DMT trip, and they seem to have similar effects in terms of how a person completely changes afterwards. The range of possible conscious experiences is really something extraordinary and most humans only ever experience a miniscule fraction of it.
(Which is probably irrelevant, but some may find it interesting)