I had a very strange experience with this the other day. In the past I'd taken 6mg orally with no effect whatsoever and then on a later occasion I took 8mg orally with 20mg of 2C-E and got very beautiful and colourful visuals from the 2C-E (similar to those at ~25mg 2C-E) and a wonderful pseudo-spiritual shared consciousness experience with the peculiar visual affect of having trouble delineating the boundaries of separate objects that I later realised was from the 2C-P. The other day I decided that I would try 11mg 2C-P (again, orally) and see how that turned out. When I came up, I experienced the same sort of pseudo-spiritual experience as before and enjoyed it quite a bit for about 3 hours. After that, I spent about ten hours in absolute peril for my life accompanied by dyskinetic seizures, tachycardia (enough to make me take 40mg of propanolol), fever, extreme openness to suggestion, confusion, dissociation, and loss of tactile sensation as the universe convinced me that it wanted to assimilate me and that it had the power to do so. Profoundly vivid hallucinations punctuated this delirium in very bizarre and personal ways (e.g. watching television programmes that were not actually playing on the television with subtitles analysing the programmes as allegories for each of my current personal problems, and, on another occasion during the trip, a change in visual distortions matching exactly those of the delirium accompanying pnuemonia and a 40.5 fever which I had experienced whilst hospitalised as a toddler and had completely forgotten about). So this went on and on and I decided that I was an utter idiot. After a total of sixteen hours, I resigned to my fate and went to bed convinced I would die as soon as I fell asleep. The next day I woke up convinced I had died and had been reborn in a concurrent universe wherein my apparent overdose did not kill me à la many-worlds denial of waveform collapse and quantum suicide, and I didn't get over that for about 12 hours. I'm still not entirely sure one way or the other.
Anyway, this experience seems incongruous with people suggesting recreational doses up to 16mg or more. Does this seem like just an allergic reaction (though it didn't seem to happen at lower levels of exposure) or could it be that what I have is not 2C-P? I don't have access to NMR spectra or anything, but M/M/S comes out plausible.
Maybe 2C-P just has very peculiar pharmacodynamics?