I wouldn't know of a direct contraindication that would suggest a dangerous interaction but considering we don't know the ins and outs of these compounds yet definitely be careful. Might I suggest that if you are used to heavy drinking where there is just one drink after another without paying attention how many you've had already... instead drink with moderation when combining with 25C. Think of a limit before you start, so that you can consider feeling 'drunk' enough, and not have to go for 'wasted'.
For safety reasons also don't start drinking until after the 25C-NBOMe has started working otherwise you have much less control over what's going on. Preferably I wouldn't drink at all on this but it doesn't sound like you want to take that advice.
For safety reasons also don't start drinking until after the 25C-NBOMe has started working otherwise you have much less control over what's going on. Preferably I wouldn't drink at all on this but it doesn't sound like you want to take that advice.