An extract is a preparation of plant or herbal using a solvent to release the active compounds from the plant material. It is believed that an herbal extract can possibly be more useful than pills or capsules containing the same herbs. The fresh or dried herbal material is macerated, placed in the solvent for a specific time and filtered to produce an extract containing the active constituents of the herb.
Alcohol/water-based extracts have a number of advantages. Because they are concentrated, a smaller amount of extract is needed; the alcohol acts as a preservative, so these extracts have a long shelf life.
Dry extracts have been developed to make the constituents appropriate for use in tablets, capsules or may be dissolved in liquid or used in other forms.