It's not about ideas. It's about you giving the equivalent of fraudulent medical advice. If you think switching affects cerebral blood flow, that's an interesting idea that would make a good scientific study. The idea that the headaches could be caused by changes in cerebral blood flow is a good one assuming your first idea is correct. You worded both as fact, making it seem like you knew what you were talking about, then you told the poster to take an herbal supplement. That's wrong. It's lying and it's dangerous.

If you want to suggest that people try something because it worked for you, do just that. Say: "When I get headaches from switching, I take X herb and it works for me."