Initial Posting: 7/15/2015    Last Update: 8/3/2017
Answer: When selecting an herbal supplement, you should be guided by clinical studies showing a benefit using a particular type of plant preparation. Things you need to be clear about are 1) the name of the plant and its species, 2) the part of the plant, e.g., the root, leaf, flower or bark, and 3) whether the product was made of the whole plant part (such as root powder, which is dried root made into a powder), or just key compounds extracted from that part of the plant (i.e., a root "extract") which are typically provided as a dried powder or liquid.
In most cases, you will be looking for an extract, in which case you will also need to know the % of specific compound(s) to which the extract should be "standardized" since there are many types and concentrations of extracts. Supplements made of whole plant plants, like root powder, are typically not standardized like extracts.
The "ConsumerTips" section of every Product Review on ConsumerLab.com covers this information, so you will know what to look for when selecting a product. Other information you find is dosage, how and when to take the herbal supplement, potential side effects, and interactions with drugs and other supplements. Of course, you'll also see whether ConsumerLab.com testing found each product to contain the listed ingredient(s) and meet additional criteria of product quality.
Here's a quick summary of popular herbal supplements, showing the type of preparation typically used: