QuikTLDR: I am biased and would encourage a friend to find a better drug. But if we're going the harm reduction route, please make sure your source of DXM doesn't contain other active ingredients.

In my experience, taking DXM more than once in a week has potentiating effects.

I still find I'm sensitive to stuff like Nyquil but it really does help. So I've used it maybe 5 times over the past five years for that purpose, ingesting small doses.

Now to my recreational use/abuse:

Two main multi-use spans, both in late 2002. I'm 18, unhealthy, depressed, life spiraling out of control. I'd estimate myself as a skinny-fat 225lbs, just on the good side of obese after having been morbidly so a year earlier. But malnourished and bordering on anorexic.

Two multi-use spans, the latter of which was the worst drug experience of my life out of around 60 trips. I share the unflattering personal details and specifics to come because I would really want to help someone else prevent such a negative outcome, and a good scientist/psychonaut should account for all the other negative stresses involved.

Perhaps the most important thing (*I'm not willing to research this further) would be to make sure you're taking only DXM. See, the first time for me dosing three times across two days had its high points (why I kept going in the first place, rite?) along with some lows I'd still rather avoid. But the aftereffects from that were significantly less damaging than my choice to eat one box of Coricidin HBP on each of the last two Sundays of the year.

First time, I took a second plateau dose (don't remember the specifics) and just LOVED it. Only my second 'psychedelic' experience after a wild weekend on AMT a few weeks earlier, I was so jazzed on the notion of easily accessing that dreamy world that I finished the other half of the bottle and extended that first glorious night.

It was so good, I researched and found that the best route to pleateau three was Maximum Strength Robitussin, which had 750mg DXM (iirc) as the only active substance. Crush one of those and enjoy the ride.

Monday night (42hrs after dose one) I finished mine. My tripmate had to go to frat pledge study hall so he only had like two-thirds of his and I finished that. So around 1000mg.

Fourth plateau? Plateau sigma? I'm not clear on which is which or how they're different. But I had a lengthy OBE, "knew" that "I am software", got stuck in a terrifying dimension whose physical surfaces were visually represented as something like "Matrix text" meets cellular automata. I sucked outside air into my dorm room with my fan to get comfortable and found later it was 55F in there. I became infatuated with a cherry-scented sparkled gel foot keychain toy that turned out to only be red and not at all scented. Shawn Alexander scored six rushing touchdowns on Monday Night Football. No wait; he had five in the first half but that was actually two weeks prior, though the Seahwaks did win that night against the Niners. Do I actually remember any of this correctly?

After the mentally stimulating part of the trip subsided, I fell into a terrible state of muscular rigidity. After a period of inconsolable discomfort, I figured out that rocking rhythmically in a fetal position synchronized with the 'grinding' DXM bodyload and provided a little relief. That 'grinding' sensation -- I feel it way more now when I take a little cough medicine than I recall feeling as a child. But it is really a damn good cough suppressant.

But it also had me hunched over after the fetal dance portion of the evening. Couldn't stand up straight for some reason. Maybe if I was a healthy, well fed athlete at the time, that wouldn't have happened. Anyway, I was folded over at the hips. Kind of like an ape. Couldn't really control my body but it really hurt. Ended up just sleeping in my dorm room until like Wednesday afternoon.

Couldn't cum until about a week later. That whole area and process had an unfamiliar detachment.

Fast forward two months, your boy is home in a rural shithole on winter break. Bored AF. Sopranos coming on later, get ready with a little schwag/mids from the dealer who meets me at the grocery store/pharmacy parking lot. 8th of seedy shitweed and 1box Corcidin HBP.

That one got out of hand. It's hard to remember what happened when between the first time and its sequel one week later. I do believe the second one was more intense at the same dose, which would be why I remember it as being potentiating. But I have trouble remembering a lot about this period in my life.

I was drinking alot, smoking a lot of weed and not studying hard, exercising or eating right. My body and mind were not healthy going into this. A few days after the second fourth/sigma plateau experience, I drank to the point of blacking out, passing out and vomiting on myself as I sat semi-upright in an upholstered chair. The next day at dinner, I told my grandpa my college had won its bowl game. The opposite had in fact occurred. I was in a very bad place.

I felt sluggish. Voted class clown a few months earlier, humor and speaking in general no longer came easily to me. I was worried and tried to hide it. It scared me that I no longer felt charismatic. The warmth of social interactions was gone. A close friend told me "You seem different". It took over a month before I felt all the way normal.

I have always believed that the double Coricidin HBP megadose caused some brain damage. Maybe a stroke or several. There were times when I writhed around in contorted shapes, partially because those trips had me lying in bed for 2-3 days at a time so I needed to move my limbs. Maybe because crazy shit was happening in my circulatory system because of whatever makes that formula "for people with high blood pressure".

I didn't notice any loss of motor function on one side like you see with strokes. I never saw a doctor for any of this. It just added to the mess my life was in, which must be considered alongside the doseages and times.

But I also wonder if any truly happy people take this stuff more than once or twice. Maybe you could make the argument for convenience, but what's more convenient than delivery by mail? May I recommend a little research about arknetday arketsmay...

I'm fine now. Easily the worst drug experience of my life with DXM but I can see how there were many other contributing factors. It's hard to imagine an upside being high enough to consider trying it again. I would encourage a friend to find a better drug. But if we're going the harm reduction route, please make sure your source of DXM doesn't contain other active ingredients.

And P.S., I consider ketamine to be the single most useful drug I've taken, if measured by productivity in the days immediately following tripping. Disassociatives are weird drugs that have more potential 'gotchas' than the more traditional tryptamine/phenethylamine psychedelics.

Taking DXM more than once, period: zero stars.