I know this is an old thread, but I think I can explain why there is so much disagreement about the effects of BDO.
Up until last year, I used it for about 6 years. Initially, the use was limited to occasional social use, around 1-5 times per month. I didn't have a steady source, so each time I was looking for GHB I would find either GHB, GBL, or BDO. For me, the highs were identical with the exception of the duration and how long it took to hit. I noticed GHB hit very quickly, BDO would take about 10 minutes, and GBL would normally take 15-30 to get the full effect. Also, GHB and GBL seemed to last about 90 minutes while the BDO would last up to 2 and half hours (although there was often a lull for a few minutes followed by a 30-minute second wave). Also, in the times that I would take too much (accidentally double-dose), the GBL would be horrific (confusion, intense stomach pain and vomiting) while with BDO I would tend to just feel a little confused, pass out for 15-60 minutes without being easily awoken.
I lived in Mexico for a while after that and was able to get cheap GBL. I was able to dose around 5-6 times daily for around 5 months. The effects were consistent the entire time. I moved back home at ran out somewhat suddenly. By the end I was using around 20 ml/day and when I quit I had some psychological craving but no significant withdrawal aside from some fatigue for about 3 days.
After about a year without it, I found a cheap and reliable source of BDO. Initially, I limited myself to 1-2 doses daily. It hit fast and felt clean, and I loved the longer duration and that I didn't have to worry about it corroding anything it touched. The high was still the same, but after a couple weeks I noticed that sometimes it wouldn't hit at all unless I ate something in my stomach (a small snack would kick it in, but on a full stomach it could take an hour or more to hit). A friend of mine brought up the argument that he didn't like BDO because it just made him feel tired and lightheaded. I insisted that it was all placebo and that they were identical chemicals in your brain. Then I learned that it isn't at all the case.
I started using small quarter to half doses to give a boost through the day, and then as later as a sleep aid. I saw no negative side effects and it felt like I had found a miracle antidepressant. At this point, I was probably using about 1 ml/hour and maybe a full dose at night, so between 24-30 ml a day. My boyfriend (an alcoholic who quit drinking but found it was a great alternative) was doing the same, but after a couple weeks he started complaining about how it just didn't "work" anymore and felt like taking Benedryl. I didn't believe him at first, but I did start to notice that if I went a few hours without it I started getting anxiety and a very uncomfortable itch all over my body.
A couple of months later everything changed. I noticed that it took more to have any affect at all and that it would only work at certain times of the day. Then it started to feel like a somewhat dysphoric tranquilizer every time I took it, but that if I didn't take it I was plagued with stronger anxiety, muscle aches, and the itch (which now started to feel like my skin was on fire). After a couple more months, I eventually decided to quit, and just stocked up on (a ton of) benzos and forced myself to just sleep through it. After 3 days, the itch, aches and anxiety (mostly) stopped, but I still felt depressed and couldn't think clearly until about 2 weeks after I quit.
GBL vs 1,4 Butanediol - Here's what it boils down to:
GBL uses stomach acid to metabolize while BDO metabolizes in the liver via the enzyme alcohol dehydrogenase. The metabolism (and effects) will vary based on an individual's levels of HCl in the stomach and the amounts of the enzyme in the liver. Hydrochloric acid in the stomach is more-or-less the same from person to person, but the levels of alcohol dehydrogenase can vary significantly. It's the same enzyme that breaks down alcohol, so it doesn't metabolize as well for people who have a history of drinking or a damaged liver. Hydrochloric acid is a simple chemical for our bodies to produce, while alcohol dehydrogenase is a very complicated molecule and the liver can eventually have trouble synthesizing it.
When BDO doesn't metabolize, it is an entirely different drug with its own effects and leads to much stronger physical dependence. I think that for many users, it metabolizes slowly (or incompletely) leaving a mix of GHB and BDO in the bloodstream, giving a GHB high mixed with some sedation and lightheadedness from the BDO. Prolonged heavy use damages the liver by either making it difficult to produce the enzyme or using all of it's stores. Eventually, it stops metabolizing at all, and prolonged BDO exposure can have strong physical and psychological withdrawal symptoms akin to opiate withdrawal.
Disclaimer: I consider myself a well-informed drug nerd with significant personal experience on the topic, but while I've done much research over the years, I don't have a background in biological chemistry. I am probably off about some of the subtleties involved. I think that the conclusions seem to explain all of my experiences and what I've heard from others pretty well. I hope that this is helpful in giving some general clarity, but it's by no means scientific and could easily be very inaccurate.
