Supplements aren't actually that hard to be approved by the FDA. There are quite a few that are damaging to the liver or the kidneys. Of course, that doesn't necessarily mean they aren't good for other things. Many drugs have horrible side effects.

It really shouldn't be medical science and alternative medicine. Sure, there should be some alternative medicine like spiritual beliefs...but...the way the medical system is... It's not always medical science. Sometimes they just prescribe what's recommended. Sometimes they ignore medical studies. Sometimes they don't do their homework and yet still act like they're infallible...

But still, some alternative medicine is just fantasy. So be careful.