Herbs don't work for everyone, just like one person can take an Antibiotic and get well, and another will not. Your body chemistry has something to do with how well anything works in your body.
Herbs are miraculous in many people, no doubt, but not for everyone. The same herbs that saved your life may do nothing for someone else.
Personally, they work well for me, as well as do supplements. I do know people who get no relief from them, though.