I have tried ~3.5 mg DOI with ~1 mg 25I-NBOMe on top. Probably about 7-8 hours after consuming the DOI.
Very nice synergy as the are a lot reminiscent IMO.
The weird thing was that i was able to sleep after 16-17 hours, but nice actually.
I would start lower with the NBOMe than 2mg though
i definitely wouldn't do it in that dose. If i were to take such a combo, which i'm not sure i would, i'd probably go with 2mg DOC, then a few hours later something like 250-500mcg of 25i, probably towards the lower end of that range. Definitely wanna test out the waters before jumping into the deep end.
That dose range is way too high. 1mg of 25I-NBOMe on its own should be a strong trip provided you're not messing something up during dosing. Why would you want to take DOUBLE that AND another drug on top? That's asking for problems, especially considering the NBOMe series compounds are notorious for terrible vasoconstriction and putting people in hospital when the dose is too high/other vasoconstricters are added in.
any major dude's suggested dosages sound much more realistic. Or 1mg DOC + 500ug 25I like Sheekle suggested.