Old school (back when it was legit) lean always hit me this way, it's fascinating how some opioids can induce visuals. I've always wondered if it's a little tinge of kappa opioid action going on, like a microdose of salvia, as salvia's visuals are not far off from these imo.
I had access to a wide variety of opioid combination syrups over the years. I once got a hold of a combination syrup that contained a high dose of hydrocodone combined with scopolamine. Both IR. I don't think it has been made since the late 1980s or early 1990s. I snatched that bottle out of a medicine cabinet that had tons of opioid goodies in it that had been stored up for years along with sampler bottles of things like lyrica. The person they were prescribed to was allergic to codeine so they'd gotten all sorts of non-codeine opioid odd-ball combination syrups from a local compounding pharmacy over the years. They never took them for longer than a couple of days and would always get a new prescription the next year when they had coughing fits. So by the time I stumbled upon that cabinet it was filled with tons of goodies some of them 20+ years expired.
I got so much lovely Tussinex (hydrocodone ER that tasted like sugar) out of that cabinet over the years.
Anyway, that hydrocodone+scopolamine bottle was wild. I already had a heavy opioid tolerance when I stumbled upon it. I knew scopolamine on its own wouldn't be very pleasant but I figured it'd be no big deal. I was wrong. I think a standard dose out of that bottle hydrocodone wise was 10mg. I took 40-50mg and got a mega dose of scopolamine along with it of course.
I ended up going into a heavy nod that rivaled a pure morphine nod. I saw real visions in those nods. I'd open my eyes and could still see them for a few moments until they'd vanish out of my sight like smoke or fog. It was really cool. The scopolamine was not nearly as unpleasant as I figured it would be. I enjoyed that bottle very much and am sad I didn't save some of it. Since I've never seen a combination like that ever again.
Nothing I ever got out of that cabinet had anything like Guaifenesin in it. It was always a potent opioid and maybe something like scopolamine in combination. Typically, the older bottles were IR opioids plus something like scopolamine and the newer bottles were stuff like ER hydrocodone. There were even a couple of bottles of extended release oxycodone and oxymorphone in some of the bottles. Stuff I've never seen before even in books. I guess they were custom made by the local pharmacy because even my large reference books never mentioned them and I was never able to find any information about them on the internet.
The person that was getting them had very unique medical history. Like I said they couldn't tolerate codeine and they couldn't take stuff like gauifenesin either. Along with a large list of other common first line drugs and OTC formulations. So they got all sorts of amazing stuff and they rarely took any of it. They'd just take a dose and put the bottle away. Then the next time they needed something the doctor would prescribe them another massive bottle which they barely touched. So by the time I came along there was so much crap stored in that cabinet that I could swipe a bottle every month for years and it would never be missed. Even when some was noticed missing they assumed it was another family member that had been caught in the past forging prescriptions for Codeine in that person's name. Which is how she got caught. The pharmacy flagged it because that person was known to be allergic and she ended up doing time for forging prescriptions. She was a heavy Codeine addict and maintained a habit for years buying it legally OTC when that was still possible and later by forging prescriptions using pads she'd stolen (she worked at a business that printed them).
Anyway, opioids can be very lovely especially in combination with certain other substances. I think a morphine+datura combo would probably be a good time. Provided you were careful with the dosing. Opium and most of the derived substances like morphine/heroin can already produce visions on their own. But when you add a little psychedelic, disso or deliriant to the mix it can take those already realistic dreams to an entirely new level. The only issue is that's one of the first effects that goes away once you build a tolerance and getting there with a tolerance becomes a thin line between a deep nod and death once you're actively addicted to them. But there is nothing better than opioids for taking the edge off the usual substances that produce visions.
As far as Gabapentin and Lyrica I've been singing the praises for both of them here for a long time. I think most people aren't away that they can produce amazing CEVs because you have to follow a strict dosing regim to obtain that level with them. The line between passing out for 12 hours and obtaining that state is very thin. Those GABA drugs also come with some risks of their own. People claim they're safer than other substances but you can easily cause seizures if you attempt to dose them high enough to obtain the types of expereinces I chase with them.
I discovered those effects myself by having access to that same cabinet of fun. There were like 50 sample bottles with 10-15 tablets of lyrica in them. I thought they were useless because I never heard anyone talk about them before and that same cabinet contained so many opioids and benzos (and some barbs). But one day I got curious and swiped a few of the bottles to try. It didn't take me long to figure out that they were really fucking fun and even better when used in combination with the other stuff I was already taking (they pair amazingly well with opioids, benzos, and weed). So they got added into my poly-abuse mix quickly.
For many years I didn't have to bother buying drugs at all. I had an all access cabinet of goodies for free. The only thing I needed was a bag of weed to go along with them. Later on when I started developing a higher tolerance and had swiped enough out of that cabinet to be noticed I stopped grabbing stuff out of there for awhile. But if I ever got broke I could always pay it a visit and get high for free for a week or two without anyone noticing. I just had to be careful not to take too much at once. But they were always adding new stock so that was pretty easy to do. It isn't as well stocked today and I don't live there anymore. But any time I visit I take a peek because I'm an addict and the old cabinet is as well stocked as it ever was.
I had other sources for some experimental stuff back in the day as well. I ran around with these two crazy brothers that loved to rob pharmacies. They'd always be showing up with trash bags full of shit and would give you handfuls of stuff for free. First two people I met that were heavy into using pharma drugs. Then we knew these two gay brothers that always had access to experimental/new pharma drugs. No idea where they got them from but they were always coming around and giving away samples. They were the only people I ever got those triangle xanax pills from. I only ever saw them in a reference book I had and that one time from them. Never seen them prescribed to anyone. I think they were something crazy like 3mg doses IIRC. They might have even been higher than that and ERs but I forget now.
There are a lot of wacky highly visual drugs on the pharma market most people aren't aware of. Many of them are rare now and aren't openly prescribed as much any more. But if you have access to an old cabinet with stuff in it from the 60s-80s you can still stumble upon them now and again. Stuff like placidyl.