2.20 Skullcap and Teucrium adulteration
The question, on the herbinfo -list in July 1998:
>I remember reading somewhere about the possibility of liver toxicity from pyrrolidizine alkaloids or adulteration of skullcap. A web search didn't turn up anything useful. (Would you believe you can type "skullcap" and "liver" into a search engine and bring up x-rated sites?)
I found plenty of information about comfrey and PAs but that's not really what I needed.
My reply (thanks for all those tidbits, MMoore):
Scutellaria, aka Skullcap is not dangerous.
However, it has been adulterated with Germander (Teucrium sp.) for decades, if not centuries; though that matters a great deal qualitywise it has no implications on toxicity as long as only the 'mercans did it, as the 'mercan species of Teucrium do not contain toxic pyrrolizidine alkaloids.
Again HOWEVER, then the Europeans thought "Hmmm, that's a great idea, money for nothing, chicks for free", (sorry, got carried away). So they imported Scutellaria from America and added their local -European- Teucrium species to it. Then they re-exported the mix to the folks on the other side of the pond... there is a very big problem with quality here, AND in this case there is a problem with toxicity. The European species of Teucrium do contain toxic pyrrolizidine alkaloids. So it's not good for your liver to buy your skullcap from sources you do not trust, like the -really- large herbal houses; THEY ALL DO IT.
To get them to stop it you'll have to ask your suppliers where they got their skullcap from. If they bought it, ask them where from; ask them to ask -their- supplier(s) where from... if it's one of the big houses ask them to PROVE that there is no Teucrium in that there Scutellaria.
Perhaps, if enough of us do this, we'll have unadulterated Scutellaria in another couple of decades.
Update: I'm told that the toxicity of germanders is caused by neo-clerodane diterpenoids, not by pyrrolizidines. Thank you Eric! 01May2019.