For a
'final word on safety' what you want is an extensive series of double blind active-placebo-controlled human trials on diverse populations to evaluate the safety, pharmacokinetics, and pharmacodynamics of harmala-mescaline interaction.
I wont see that in my lifetime, I only expect to live another 50 or 60 years
What can be said is that, across the various ethnobotany/drug platforms and forums, dozens of people have reported using the combination and it would be radically conservative to say that for each report there are at least ten unpublished experiences. So at the very minimum, hundreds of people have done it without even counting more or less traditional cimora brews. People here routinely monitor medical publications for mention of psychedelics, no case report of a clinically significant reaction to mescaline+harmalas has ever been seen. Very few people who have tried it report any negative at all, and those that are seen could just as easily have been triggered by mescaline alone.
I remember one person say they combined harmalas, mescaline, and caffeine and had an unpleasant sensation of racing pulse rate and because of that were suspicious of harmalas. I can get that reaction just from combining a cup of coffee with one
tenth of a dose of mescaline, no harmalas.
With hundreds, probably thousands of people doing it and no reasonably concerning reports of negative interaction and certainly no fatalities, I'm personally not worried.
I've done the combination something like 3 dozen times and never had any 'negative' effects that didn't also routinely occur when using plain mescaline, mushrooms, or pharmahuasca.
As to how it effects the trip. For me it increases the trip intensity by roughly 50%, like harmalas+375mg mescaline has the effect of 500mg and harmalas+more than 500mg mescaline is only for the experienced tripper. I've heard some others say it doubles the potency for them, so go easy the first time.
It usually shifts the visual aspect toward a somewhat more pharmahuasca or LSD patterning and coloring, which of those directions it takes seems to depend on the cactus used.
I have an uncommon, but not unique, idiosyncratic response to cactus tea. An active dose of cactus tea gives me an arthritis-like sensation in my joints and other connective tissues, I've mostly heard of this effect in old men but I'm still young
As a result I had to entirely stop taking cactus tea. However, under half of a dose of cactus tea taken with harmalas gives me a opportunity to gauge the potency of the cactus without experiencing much of the arthritic effect, so thats a positive. [Though, in current practice, I now only use orange or white refined mescaline. Neither of those produce arthritis in me, thank the gods.]
I've never had much cause but at times have monitored my blood pressure and pulse on pharma, mescaline, and mescaline+harmalas. Systolic, diastolic, and pulse can all be elevated proportional to the intensity of the trip but I've never seen a dangerous blood pressure or pulse rate. At most its the numbers I see while resting between sets while weight lifting, not surprising given how stimulating psychedelics can be to the body.
Um, what else. I've repeatedly tried including moderate-dose [150mg] THH•HCl with the harmalas and mescaline and then followed that on a subsequent occasion with an identical dosing minus the THH. I did this all the way up to 750mg white mescaline•HCl washed down with harmine solution [an advanced dose by any measure] and in those trials I did not see THH having any unequivocal effect on the trip. I have yet to try THH•HCl at doses of up to 450mg with mescaline+harmine but it is on my list of things to try before giving up on THH+mescaline entirely.
The last thing I can think of is more of an open question. On my new years dose I wanted to shatter my old reality so I could have a brand new reality for the new year. I had just finished a scopulicola extraction with the predominant european T. scopulicola clone, a species I had never tried in refined form, so I decided to wash 625mg of orange scopulicola•HCl crystal pills down with 200mg isolated harmine•HCl in solution and then at the 3 hour mark take a capsule containing another 200mg of harmine•HCl so as the mescaline peak was on the downward slope the second harmine dose would be peaking in my blood so I could smoke some DMT and blast off. Well I got to the second harmine dose and then never did the DMT because even without it reality just cascaded in on itself and shattered. I was my childhood self, I was my grandmother, I was a forest shining pearlescent rainbows from my leaves to sing light to the stars, I was a rainbow, and I was quite, quite fucked up
This trip was the most visual and the most color-centered mescaline/cactus trip I've ever had. I am now just vibrating with anticipation to find opportunity to experiment and attempt to discern if all that happened because A] unrefined scopulicola alkaloid is freaking phenomenal, B] harmala re-dose just before mescaline peak re-intensifies and re-tunes the mescaline in a remarkable way, or C] random chance and luck.
Is cacti + harmalas safe? You judge. Either way, I'll continue!
Its a brave new world, with such psychedelics in it.