The next time someone suggests you take a dietary supplement, or a plant or herb extract, or tells you to eat, drink, apply on your skin, inhale, or do anything with the argument that it's natural, remember this:
NATURE HATES YOU
Almost everything that comes from nature will kill you. All animals would prefer that you die, all plants are toxic, and it's only through a long evolutionary process that you are barely capable of digesting any vegetables.
There is a reason why we take aspirin instead of chewing bark, and why we cook meat before we eat it. Freaking potatos are toxic if eaten raw.
Give parsley to a parrot, give chocolate to a dog, give celery to a cat, give hemlock to you: DEAD. Because all around you is trying to kill you. All the time.
Nature is not a mother, nature is actively hostile to you and will be happy to make your life as hard, brief and painful as possible. Man has changed that. Saying "oh, but this is natural" is an indictment, a warning sign.
Raw foodists, paleo diet advocates, herbal-supplement-chuggers: you are all the beneficiaries of a long history of knowing what is semi-safe to eat because everything else will kill you.
I will not eat anything nature gives me until it has been carefully tested by men and science. Because science is good and nature is evil.