Do you anything about herbs specificlly Comfrey

Comfrey as a cream may help wounds heal. Comfrey by mouth can kill you.

The harm is well documented. Comfrey contains pyrrolizidine alkaloids, chemicals that damage the liver. A 23-year-old man in New Zealand who ate comfrey leaves daily died of hepatic veno-occlusive disease, where small liver veins plug up and the liver fails [1]. The same alkaloid class causes liver disease, cirrhosis, and cancer concerns in animals and contaminated foods [3][4]. In mice, chronic low-dose exposure produced liver tumors and liver damage in most animals [5]. Regulators set tolerable daily intakes near 1 microgram per kilogram of body weight, and Germany allows zero in herbal products for pregnant women [4].

The benefit side is thinner but real. One randomized double-blind trial in 108 children with skin abrasions tested a 10% comfrey leaf cream against a weaker 1% preparation. The 10% cream healed wounds in about 4 days versus about 9 days for the weak preparation [2]. Note the comparison: both groups got comfrey, just different strengths. There was no true placebo arm, so the trial shows the stronger cream beats the weaker one, not that comfrey beats doing nothing.

The retrieval did not surface trials of comfrey for sprains, back pain, or other common uses, so I cannot weigh those here. What it does show is enough for a clear rule: keep comfrey off the skin of broken skin and never swallow it. Topical use on intact skin, short term, is where the benefit evidence sits; internal use is where the deaths sit.

My call: comfrey cream on intact skin for minor wounds is reasonable and has trial support; comfrey by mouth is a firm no, because the liver toxicity is proven and the dose that hurts is not well known. Confidence: high on the toxicity, moderate on the wound-healing benefit.