OK to do? Well you would probably get away with it but the resulting experience wouldn't be all that special. I believe if both times the dose is snorted you will get relatively more from the second go, although generally speaking you will get more from oral administrations. That is the choice you would have to make.
It's not really worth your while like it is with many uppers and downers when redosed.
I find dosing the day after is even a waste, including hefty compensation for tolerance the second time around. It's just so shallow and entirely not as sparkly. Both to the mind and to the eye.
I find redosing most 2Cs I've tried works pretty well, personally. Have redosed 2C-B, C, D and I all with no problems other than maybe feeling a bit tweaked, burnt out and frazzled with some of them (step forward 2C-I ). With 2C-B (and most of the others) I find either an oral/rectal dose followed up with snorted doses works best or just snorting from the start. Bloody sore, mine. I cut my 2C-B with 2C-D to reduce the pain factor and up the swirl factor considerably. Intravenous 2Cs also work well for redosing but it's not an MOA I could wholeheartedly recommend due to health concerns (heart issues in particular) and increased side-effects. Although a night shooting 2C-D is pretty damn sweet - it's the only 2C I've really enjoyed IV, to be honest.
Meh. Not such a fan of IV 2C-I. Too much strain on the heart for my taste. Incredibly brief too. Instaswirl is always good for a giggle but it wouldn't be my first choice, to be honest.
I've redosed on it before, getting pretty much full effects from the same dose. 20mg if memory serves correct. It did make the muscular strain a bit more pronounced, and left me with a banging headache (probably more dehydration and alcohol hangover as well).
i find 2CB very forgiving especially when redosed, i always find oral dosing not as strong or potent as snorting 2CB, i find snorting 15mg every 3 hours to produce nearly identical effects, apart from the obvious first come up
I've noticed that tolerance grows very quickly to the 2C family.. but as a one off its not problematic... i usually go on 2C binges for 10-12 days at a time... by the end i'm blowing 50+mg lines, but i space out the binges... i'm not encouraging binging... just saying that your tolerance goes up like crazy when using 2Cx over and over in a short period of time... but redosing once should be fine....