The strength ratio listed
on liquid extracts is a weight to volume ratio (gram:ml)
1:1 = 1
gram (1000 mg) per 1 ml (20 drops)
1:2 = .5 grams (500 mg) per 1 ml (20 drops)
1:4 = .25 grams (250 mg) per 1 ml (20
1:5 = .2 grams (200 mg) per 1 ml (20 drops)
2:1 = 2 grams (2000 mg) per 1 ml (20 drops)
Note: Simply because a company
used 1 gram of plant to 1 ml of alcohol does not mean you are
necessarily getting 1 gram worth of plant matter per 20 drop
dose - this depends on how readily the active constituents of
a plant dissolve in alcohol.
Also, Fresh Extract and Dry
Extract strengths cannot be compared. Fresh Extracts will often
appear to have a stronger ratio because the company must compensate
for the water mass of a fresh plant by adding more of the plant.
Thus, a 1:5 Dry Extract is frequently stronger than a 1:1 Fresh
Extract, depending on the plant in question. Herb Pharm
extracts tend to follow Pharmacopoeia guidelines for selecting
fresh or dried plant, Gaia tends to follow a "fresh is better"
approach; there is most likely validity to both arguments.
Gaia brand extracts use a
method known as "double maceration" - a 1:1 extract
from Gaia is a 1:2 extract in which the plant material is replaced
with fresh plant material after the first extraction. This may
or may not make an extract stronger depending on the plant and
the solubility of the plant's active constituents.
In summary, it is nearly
impossible to tell how strong an extract will be until you try
it yourself. "Standardized" extracts, in which
a company tells you the concentration of active constituents
(most companies will only test their product once despite seasonal
crop variations), are not necessarily stronger than a normal
extract. The best advice we can offer is to find a brand
you like and stick with it.