Last week, a friend asked me what I thought of herbal remedies. (She probably regretted it almost instantly.)
While others have done an excellent job summarizing evidence, and lack thereof, about herbs, I want to reiterate what I told my friend, because I think it's the most overlooked point about 'using plants like out bloodletting ancestors who frequently died in childbirth and of common infections': any dose of something large enough to have an effect is a dose large enough to have a side effect. If herbs work, it's because there's a real, bioactive component. We call those drugs.