St. John's Wort: Choosing A Brand
Standardized Extracts: What Do The Numbers Mean?
Why is using standardized extracts of herbs or plants so important? According to Dr. Andrew Weil, author and founder of the Program in Integrative Medicine at the University of Arizona, "Standardization is the best guarantee that a product contains what it's supposed to contain in amounts sufficient to produce a desired effect."
Standardized extracts of herbs and plants are concentrated essences of one or more selective ingredient(s) at a particular level. Using a distilled constituent of a plant or herb can amplify the known or tested effects, which may be important in treating certain conditions requiring consistent high dosages of said herb or plant. Look for the compounds in the plant/herb that is standardized in order to determine what you are really buying and in what amounts.
Good clinical trials evaluate the therapeutic effects of herbs or plants using standardized extracts in order to ensure dependable results. Therefore, many of the published clinical studies that have shown the effectiveness of St. Johnís Wort for depression and anxiety have used extract standardized to contain 3% to 5% hyperforin. As a result, look for St. Johnís Wort standardized to at least 3% hyperforin for proven result in treating depression and/or anxiety.
Note that St. Johnís Wort can be standardized for hyperforin (usually 3-5%), hypericin (0.3%), or both. Since recent research shows that hyperforin is the primary active constituent, an extract standardized only for hypericin (but not hyperforin) may not be the best choice.