Take a look at alcohol. As a drug I can't think of one with a longer history of use. I consider it at least as dangerous as heroin, legal issues aside. I don't know where you're going with this, anyway that's my opinion.
This is pretty much exactly what I was going to say. Throughout history, there will always be in any given culture and for any given drug, three or four groups of people: those who completely abstain from it, people who try it once or twice/very occasionally, those who use it fairly regularly
but still
responsively, and those who abuse it. Obviously, the amount of risk posed to the user goes up for each one of those categories, so it's really just a matter of figuring out the sweet spot between enjoying it and being safe.
Cocaine is a fairly good example, too: it was traditionally used for a
very long time in Central/South America, for increasing stamina, decreasing hunger, altitude sickness, etc. The amount of people who regularly used it in that way was pretty high (and remains so in certain areas), but the amount of abuse was fairly low, quite possibly due to the fact the onset of the effects is slower and less acute than cocaine as it is taken currently.
This same story can be applied to many, many traditional drugs.
So play it safe, especially as there doesn't seem to be a whole lot of documented research on it. In some ways, I "trust" traditional preparations/uses of drugs a good deal more than modern preparations of drugs. For example, if I were in South America, I'd totally try coca leaves or coca tea, but as it is in my country, I probably wouldn't try cocaine.
(Side note: Thanks to the OP for mentioning this herb. I might see about getting some of my own and trying it out.)