I did this recently. I am sensitive to both. i took 600 mg of Gaba earlier duuring the day, then in the eve I took another 300 before I went out. I was feelin' pretty groovy but decided at about 10pm to take a 1/2 hit of LSD just to get a little trippy as I was at a cool DJ show. I didnt drink any alcohol but I smoked lots of pot when I was out. I felt a little trippy like shroomy but fairly electric....Started feelign kind of weighted down by the LSD so I popped another Gaba around midnight. I felt like I could tolerate that much since I had been taking them a couple weeks and built a small tolerance, plus I heard they were hard to OD on. I was at the club tiil 2am feeling trippy, but like I totally had a grip. I got home and was feeling really nice and only a little trippy. I smoked some kind bud and had a glass of wine and TOTALLY TRIPPED BALLZ in La La Land. I was by myself and I put on some light music and went on the internet for 5 minutes and went into some kind of internet hole that put me on another planet. It was about 3am and I was really tripping my fucking face off now. It was as if that small bite of the tab of acid was super potent, and all the gaba caught up with me plus the wine and bud. Holy crap. Ive done some trippin' in the past 10 years but I am usually too cautious to let something like this happen to me. only during a DMT trip have I felt this out of it in many years. I just took the acid over a month ago by itself and it was good but this was really a sub reality. It was much too dreamy for me to really enjoy like I do a shroom or acid trip alone. I like the gaba alone. I think this whole mix was very sketch. I could NOT grip reality for a couple hours. I tried everything....showers, walks, food, barfing...nothing could snap me out until my body was finally chillin' and I laid down and finally slept. Who knows maybe you like that sort of Super out of it thing, but I prefer taking a vicodin with the LSD. And a Benzo just kills the acid high. I think the Gaba would of been a good mix if I didnt take any during the day. That stuff take a LONG time to onset and stays with you for Hours. Just be cautious and remember that. I think it could also delay the LSD from hitting.
