I disagree, 500ug of 25i is definitely an active dose unless you have very high psychedelic tolerance, when I first started getting into NBOMes a couple of years ago most UK vendors were selling tabs around this dose which worked well. If he finds the high underwhelming he can always drop the other half later. 1000ug at once is an intense dose for someone inexperienced with the drug and it could be too much for him.
I'm finding this very interesting... From my experience, 1mg was only enough to give me slight OEVs, no CEV and a small body high.
The amount it took for me to start getting intense visuals was around 3mg. That was an experience for sure. I could have a pretty high tolerance to this, my tab could have had a much smaller amount than I had suspected or I could just be correct; either way, if a quantity as small as 1mg is gonna kill the fella, he might as well get his full moneys worth out of it.
There's no way to know how much is on his tab, so don't guess. Telling him he should take the whole thing is not good harm reduction in this situation. If it was 1000ug of 25i-Nbome on the tab, half that will be definitely noticable.
You're absolutely right, and I shouldn't have guessed. I was just saying that because it seems like most tabs I see are between 900-1200, so 1000 is a good bet.
I do want to mention that having discussed this with someone who is, shall we say "in the field," his opinion was as follows:
NBOMe is not dangerous if taken in the correct dosages. There are instances of deaths occurring, and largely they're due to improper usage. (He referenced a girl snorting 0.3g and a bathroom chemist attempting to synthesize his own from a similar chemical and selling it afterwards, resulting in a number of deaths)
I can't tell you if this is true or not, but I can tell you that I took 7mg and came out on the other end fine.
I don't recommend taking NBOMes from anyone who you don't trust with your life, I do recommend checking your acid to make sure it's acid, and I also say that if you are at all hesitant you should entirely avoid this substance.