As of this writing there are a number of pro GHB substances available on the market. They are called pro GHB because they become GHB, technically gamma hydroxybutyric acid, in your blood almost immediately through an as yet unknown enzymatic action. These two are Gamma Butyrolactone, GBL, Furanone di-hydro); and 1,4 Butanediol, (1,4 BD, Butylene Glycol, tetramethylene glycol). They are marketed under different names with some combinations of ingredients but they are all essentially the same, a pro GHB substance.
GBL differs from 1,4 BD slightly in side effects. Reports indicate it may give heavy users headaches and horrible breath. It tastes like shit too. 1,4 BD has no such side effects and tastes much better, a bitter, quinine-like flavor one can actually acquire a taste for. I prefer 1,4 BD totally.
The difference between these 2 and GHB salt is very slight. They come on just as quickly but the ramp up is smoother. You don't get the "dawn effect" of GHB where you snap awake refreshed and ready to go - at 3 AM. I get a sleep of normal length. But in all other respects, these substances may as well be GHB. In fact the studies all refer to GHB studies because I guess it is almost impossible for GBL and 1,4 BD to be in your blood and not become GHBA. The study of these substances in your body is, in fact, the study of GHB is what it amounts to.
I have found 1 ml of 1,4 BD to be equal to 1.5 g of GHB powder. This is in contrast to other opinions on the Web but I stand by my call after 12 months of daily experimentation. In fact I use nothing but 1,4 BD, Rejuv@Nite brand, now and I prefer it that way. I highly recommend it over GHB.
Oh yeah, almost forgot to mention the most significant difference between GHB and these 2 pro G substances - they are LEGAL. And likely to remain so in the near future the case of 1.4 BD. GBL is already being controlled in certain places as a "steroid substitute". Look for increased control.
Any personal reports, thoughts or response on this?