Herbs can have dramatic immediate effects but in some circumstances need to be taken for long periods of time. It is necessary to know that some herbs should be avoided with conditions such as high blood pressure, pregnancy and epilepsy, or others. Dried herbs come in whole, cut or powdered form. Powdered herbs lose their potency fastest. Liquid extracts or tinctures are basically the same thing.
Extracts generally have less alcohol content than tinctures.
Extracts are very convenient and have years of shelf life. They are concentrated forms of herbs and one only uses a dropperful or less. Powdered extracts are concentrated instant powders. When put in capsules taste is not an issue and one still gets the concentrated strength. Another advantage to extracts, as well as teas, is they require little digestion and are easily absorbed.