This was some fairly good info that said much of the same thing that I found in my medical database. I can't send a database link because it requires a student password, but this gave some good info about potential risks. Sounds like it's not indicated for pregnant or nursing women, people with high blood pressure or heart disease, or people with liver disease. I don't see anything in either place that says it's used to stimulate the immune system or accomplish "head-clearing," although perhaps he feels that if it helps clear his sinuses or lungs.

It's thought to be helpful in infections in the mucus membranes like lungs, nose, etc., assuming that's what someone really gets in an herbalist store. That's the problem with these supplements is that someone can put any name on the bottle or bag and say it's goldenseal, and it could be anything, really. There's no oversight of natural product bottling or manufacture.

Goldenseal - What You Need to Know About Goldenseal