The U.S. Food and Drug Administration (FDA) has little authority to regulate many supplements -- and the fact is that not all supplements are safe. Here is a report about two men developing advanced prostate cancer after taking "herbal" supplements.
Gray Iron advice is this: Do not take supplements of any kind without first knowing that they are safe. And a product labeled "natural" does not necessarily mean that it is safe. Above all, do not believe advertising on web sites that promise the fountain of youth. So-called "hormone therapy" can be a dangerous thing and should be considered only under the guidance and care of a good medical doctor.
Read full story here: "Natural" supplements caused cancer in 2 men.