A whole herb supplement contains the entire herb, including the roots, stem, flower etc.
Taking the whole herb is the traditional approach to supplementation–it’s believed that all parts of an herb work together more efficiently to improve overall health than individual components of an herb.
Herbal extracts contain compounds extracted from the plant–specifically their active ingredient.
Herbal extracts are often “standardised” to contain a certain amount of a beneficial substance. Standardization can help ensure that every batch of an herbal extract contains the same amount of a beneficial compound, so no matter which bag or bottle you order, you’re getting a consistent percentage of active ingredient.
That ratio you see denotes the potency of a particular extract. If it’s a 10:1 extract, for example, that means that ten parts of the original plant are going into one part of the final extract, making it a highly concentrated powder.
It also means that powder extracts can be more potent than the plant from which they are sourced, which is why you’ll notice that sometimes (but not always), dosages for whole herb supplements are much higher than those for extracts–the greater the potency, the lower the dose to ensure the supplement is safe for consumption.
The strength of herbal extracts are generally expressed as a ratio of dry plant material to final extract quantity, also known as the drug extract ratio (DER). It is expressed in the following format:
X : Y
Y = weight of dry plant material
X = weight or volume of extract (depending upon whether extract is a solid/dry extract, or a liquid extract)
The concept here is that the essential activity of the dry plant material (X) is found in the quantity of extract (Y). Or in other words, Y quantity of the extract is equivalent to X quantity of the dry plant.
Remember that ratios are fractions – ie. a 2:1 is the same as ½, a 3:1 is the same as 1/3 and a concentrated 4:1 is equivalent to 4.
For example, a tablet quoted as using a 10:1 extract, means that 10 kg of raw herbs were extracted down to 1 kg of dried powdered extract.