Hey Jiggling, Welcome to the Nexus man.
Harmine is about the weakest of the three with a starting dose of around 150-200mg. It is claimed to be easier on the system and less sedative than harmaline which has a starting dose of around 100-150mg.
I don't have any experience with THH because I refuse to support Flowing Visions and we haven't found a way to isolate it yet that I'm aware of. I would imagine the starting dose would be around 100-150mg as well but that's just speculation on my part.
THH is said to be the holy grail of harmalas with the most visionary effects.
Harmine is the next runner up with harmaline being one of the more "aggressive" harmalas.
I enjoy the sedative effect of harmaline on it's own when trying to sleep but for spice, I recommend the harmine.
You can also smoke or enjoy the harmalas sublingually and in this case the dosage would be around 20-40mg. Be careful when smoking or taking them sublingually because they are WAY more powerful and you don't want to over do it. Headaches and other nasty side effects can happen pretty quick.
Keep in mind that everyone is different and some will require a bit more or a bit less. Always start low and work your way up, just like anything else.
There is a lot of great information in the harmalas forum but it requires a bit of digging.
Convert a melodic element into a rhythmic element...