Hi Yuki, Indeed, there is such contention about Comfrey and other plants in this family. I found a huge area of coltsfoot in flower this weekend and was very tempted to harvest some. I still find there is nothing quite like it for coughs and such a small amount needs to be used. But better safe than sorry. I was spending time with a Welsh herbalist in March and talking to him about the PAs in the family. He says he’s never seen or come across any problems in his 30 years of prescribing comfrey. Short term use, low doses, probably OK but again, better safe than sorry.