Drawn to your question, I visited your profile. Your username and hubs are intriguing. I am interested to read about your epiphany!
To try to address your question, I am considering the phrase, 'a moment of pure epiphany.'
Well, in a nutshell, yes to the first part.
I have experienced several epiphanies, over the years. Wait just a minute while I look up the word 'epiphany.' Be right back.
Okay, here is one definition, 'Epiphany (Koine Greek: ἐπιφάνεια, epiphaneia, "manifestation", "striking appearance") or Theophany (Ancient Greek (ἡ) Θεοφάνεια, Τheophaneia meaning "vision of God"), which traditionally falls on January 6, is a Christian feast day that celebrates the revelation of God the Son as a human being in Jesus Christ.'
Oh! Well that is news to me. And I am guessing it is not what you meant.
In a broader sense, if epiphany can be applied to extraordinary experiences of expanded awareness, then my earlier statement still stands. I have had several this lifetime, and none while under the influence of hallucinogens.
Since there were several occasions, I was doing different things. And to tell what they were about would more than fill this answer space, though I'd be glad to share.
Some were at times of making difficult choices, when I was at a crossroads.
Some were under very difficult circumstances, and were a flash of light in the darkness.
Some were when I let go of resistance and relaxed into trust.
Some were very non-dramatic, more like a dawning realization. They can seem very small insights, yet have the effect of a full-blown epiphany.
As an example, just this week I pondered about letting go of resistance. In a conversation with myself, I asked, 'Resistance towards what?' The answer came, 'It is not a question of resistance towards anything in particular, but any type of resistance.'
With this realization, I have become more aware of how pervasive resistance has been in my life, and am more aware now when my body contracts subtly at the first hint of resistance. Letting go more freely, I also expand more readily into an encompassing view of life.
Some epiphanies were spontaneous, out of the blue.
Some occur in the stage between sleep and wakefulness and are real experiences in the subtle planes.
Now, how about you?