Are there any herbal medications that are dangerous to take while in flight?

Blood thickeners: One precaution while flying is to avoid deep vein thrombosis which is more likely if you have a tendency to form clots more easily. That said, I am unaware of any herbal medication that does this.

Only if interacts: I agree with Dr. Porter that the only herbs that might cause problems would be those that increase risk of blood clots but, like her, I don't know of any that do this. However, IF you take blood thinning medicines, esp. warfarin, there are hundreds of medications, herb and foods than can reduce its effectiveness so you would want to check for interactions.