My experience is only with east coast USA powder. I'd start with a tester. Just a small bump to gauge quality. Wait ten or preferably 20 minutes. If you feel nothing, do a larger bump. Keep slowly upping dosage over time till you get where you need to be. In my current locale, and for me personally, one bag (.1g or 100 mg) is comparable to one 30 mg oxy. This is shitty dope though, and yours could and should be exponentially better. Until you try it, it's best to assume that what you have is extremely potent. It decreases the possibility if fatal mistakes.