I have taken ~ 1 gram Peganum harmala every day for 3 days, on the fourth I plan to take ~300ug LSD. I think I am noticing the reverse tolerance. I haven't been able to find any consistent descriptions of how quickly it develops. I've heard anywhere from the second day to the second week. What is it?

And does anyone know of the mechanisms that cause this?

Ime, the reverse tolerance forms faster when taking higher/heavier dosages, whereas lower dosages take longer to build up the reverse tolerance however it can be noticeable little by little. With 1 gram of Rue though i don't think it'll form the reverse tolerance, could be wrong though, but i think i've noticed that below 2 or 2.5 grams it doesn't form a reverse tolerance, either that or it just takes a lot longer.

As far as the mechanisms for it goes, it may have something to do with the CYP2D6 enzyme because Harmalas are metabolized by CYP2D6 but also inhibit CYP2D6 so in essence they inhibit their own metabolization. I think also it has something to do with some of the receptors Harmalas bind to can become desensitized, while maintaining their other properties, so things end up feeling cleaner, lighter, nausea/vomiting/diarrhea free, reduced and cleaner body load and reduced motor impairment.