It's in the Ranunculaceae, and I'm not terribly keen on using plants in that family, which also includes buttercup and black cohosh, because all of them are somewhat poisonous. Paracelsus established an important doctrine of toxicology, which was that it wasn't the poison that was poisonous but the dose. With the exception of carcinogens, there are safe doses of all toxins, and since they are toxic because of their effect on the body it often turns out that they have useful actions at lower doses. For instance, cayenne or chili pepper is a useful circulatory stimulant but if you drank two litres of Tabasco sauce it could kill you because it would cause so much vasodilation that the heart wouldn't be able to push blood round the body any more. The ratio between the dose of an agent needed to kill someone and the dose needed to have a positive effect is called the "therapeutic index", and in herbalism at least, the ratio should be at least ten to one.
Traditional Chinese Medicine and contemporary Western herbalism differ in this respect because the plant remedies used by the former tend to be fairly toxic, or perhaps "active", by the standards of the latter. Western herbalism nowadays tends to use the likes of reflex actions brought on by taking the remedies more, such as the bitter, sour and sweet reactions and the soothing expectoration of a mucilaginous herb which soothes the digestive and by extension the respiratory system.
Consequently I'm not enormously happy about using herbs which are poisonous in even fairly small doses.
|By H. Zell - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=8950508|
Another example of this is Cimicifuga racemosa, now known as Actaea racemosa, black cohosh, which when I take it just somehow feels toxic and damaging, and which is in the same family. Of course a feeling is not enough to base such a judgement on, but throwing up after taking it and spending the next day in bed feeling like death warmed up is, particularly when I am not generally a puky person. It'll be no surprise that it's also in the buttercup family.
Even so, it's not the toxicity of Hydrastis canadensis which bothers me. There are plenty of good herbs which are fairly poisonous but still useful, such as deadly nightshade, It's a frightening sounding herb and I've never used it myself but it's potentially good for all sorts of things, in tiny doses of course.
My objection to goldenseal is not its toxicity but the fact that it is rare, endangered and harvested unsustainably from the wild. Its rhizome, the part used, grows about an inch a year, and it's difficult to cultivate. This more or less means it has to be uprooted and it won't grow back. All of its actions are replaceable by much more common and more sustainably sourced herbs.
It's well-known for containing berberine, the substance whose structural formula is depicted above, which is naturally also in barberry - Berberis vulgaris:
Berberis species, of which two are used in medical herbalism, are more distantly related to buttercups but still in the same order. It's so common I can take a rather blurry photo of another species, Berberis aquifolium, from where I'm sitting now:
This is of course called Mahonia rather than Berberis vulgaris, and the vulgaris part of the name means common, but both species are pretty common, easily cultivated and if you want to go down the route of thinking that isolated active constituents are all that herbalism is about, there's your berberine. Berberine is antifungal, lowers blood glucose (along with a load of other things which do the same, notably onions) and can correct cardiac arrhythmias, among other things.
I never use Hydrastis canadensis because it's endangered. Whether it's useful or not, it can't be used ethically or prudently. It's mined from the environment in the same way as the likes of cod are overfished, and it's not responsible to use it. This is what I tell everyone who asks for it.
That's another thing of course: people ask for it. I am of course entirely open to the idea that just because I happen to be a herbalist, even an experienced one, doesn't mean I know what's best for my patients, but this is the usual story of people looking something up on Google and deciding it's what they need from biassed write-ups on sites trying to sell them stuff. That's not what herbalism is about. Whereas it's important to respect the opinions of patients, I would respect them a whole lot more if those opinions were based on their personal experience or the experience of people with broader first-hand knowledge rather than something they read on the internet. I do have a great deal of respect for supposed "lay" opinion, and in some ways a herbalist is just a nexus for tips picked up by her patients that she can pass on to other patients, but those tips need to be reliable and properly tested and checked.
I've mentioned this issue before, but it bears saying again. Hydrastis canadensis, like many other rare herbs from distant sources, may be a "Veblen good" in economic terms. A Veblen good is a commodity whose price increases with its price: the more expensive it is, the more people want it.
|By Periodictableru - Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=9774375|
Another example of a Veblen good is platinum. All the platinum that has ever been mined in history fused together would probably be just big enough to make into a solid armchair-shaped and -sized block. Consequently it's sought after and makes good jewellery. If you are going to buy someone a platinum wedding ring, the more expensive the better.
Hydrastis is another such good, and there are plenty of others in herbalism. Veblen goods include status symbols and in the case of herbalism, there is actually an argument for going along with the idea of Veblen goods because the more expensive medicine might have a stronger placebo effect. However, it would also be nice to be able to uncouple the placebo effect from the materials and procedures associated with them and just use it as such. Then again, the efficacy of herbal remedies does exist besides their placebo effect and herbs generally are ideally free from the commodification and intellectual property issues associated with pure drugs. Consequently, when people want Hydrastis I will always say no, because wanting Hydrastis is entirely foreign to the spirit of herbalism at its best.
I was going to say something about multi-level marketing at this point but that can wait for another day.