I also encourage you to look at my blog, and read articles like the ones linked below.
I am the president of the American Psychological Association. The APA has an official position, and I am using it as an example for this post. APA Position No. 8 (pdf) is about stress. It discusses three main ways to improve life in stressful situations, and how to do that is largely individualized. If you are reading this, and I don't believe you have any of the above-mentioned concerns, then maybe you should take a look at their position. Some examples of the products sold on the market have very specific medical uses. Some of the products (like the products mentioned above) are based on the idea that the idea of taking a pill to reduce stress can be harmful to one's health, and you should avoid taking them. Others (like the ones above) have medical applications, but are marketed specifically to a doctor or other professional to reduce stress. These ideas are very different, however, and it's difficult to determine which is better.
You have to consider the pros and cons of each idea. A lot of people may be willing to take some of these products (or use a combination of them), or be willing to switch from something they are currently using, but many people don't want to change anything, and would rather live the way they are now.