The best dose would be to take 200ml and flush it down the toilet. 1,4 is shit. It is a dirtier high that GHB or even GBL. Over the past two years I've done a shitload of GHB, GBL, and 1,4 BD. 1,4 BD is addictive as hell and gives you a shitty high. Withdrawl is also a bitch. I took GHB daily for 6 months and had no withdrawl but I used 1,4 for 2 months and I felt like I was going to die.
Saying it converts to GHB in your body is like saying andro converts to test in your body and we all know thats shit.
Stay away from it. I wish someone had warned me. I lost alot of money and alot of relationships because of that shit.
If you want to have fun, find some GHB.