Symphytum Officinale Extract Worst Irritant No known benefits Symphytum Officinale Extract description _Symphytum officinale_ extract (also known as comfrey) is the extract of a perennial herb. Topical application of comfrey has skin-soothing properties, but it is recommended only for short-term use and only then if you can be sure the amount of pyrrolizidine alkaloids is less than 100 micrograms per application - something that is impossible to determine without sophisticated testing equipment - making comfrey an ingredient to avoid. The alkaloid content means it has the potential to aggravate skin. Related ingredients: Comfrey Extract