Jatos, whats up man, I guess these guys thought you were a newbie when you have a ton of posts over at Triedia? I saw the GBL you are talking about but I don't know how it could be concentrated. Normally, GBL comes in like 260ml bottles at what I think is full strength (its pure GBL). I would get it from somewhere else, because you are either getting ripped off on the price or you have some weird concentrate that could be dangerous or unpredictable. As to turning it to GHB, the instructions are all over the net. Go little evil.