Medicinal herbal preparations
What is it?
Herbal preparations are available in many different forms. They can be found or purchased as bulk herbs, teas, tinctures, fluid extracts, and tablets or capsules. It is important for doctors, pharmacists, consumers, and anyone else who routinely recommends herbs to understand the differences between these preparations, as well as methods of expressing strengths of herbal products. The following is a guide to help you better understand herbal medicines:
There are two basic ways of preparing an herbal tea, by infusion or decoction. A third method, known as maceration, is also included here. The usual dose is 1 to 2 teaspoons of the herb to a glass or cup of water (approximately 150 milliliters). Unless otherwise directed, teas are best taken fairly hot, on an empty stomach, away from meals.
- Infusion: Made from steeping an herbal tea bag in water or by using the delicate herb parts, such as leaves and flowers. They are steeped in hot water and strained to make a tea.
- Decoction: Made by boiling the hardier plant parts, such as bark, wood, stems, and roots. They are strained to make a tea.
- Maceration: Made by soaking the herb in cold water. This usually is done to mucilaginous (jelly-like) herbs, like marshmallow.
There are three different types of extracts that may be encountered:
- Liquid extracts are a popular and convenient form of herbal medicine. They are made in a variety of ways, such as heat evaporation, cold percolation, or through the use of high pressure. The herb is first soaked in the appropriate solvent, such as alcohol, and the medicine is concentrated via the distillation process.
- Solid extracts are made similar to liquid extracts. The medicine is further concentrated by distillation or another drying process. This leaves a more honey-like consistency or even powder-like.
- Extracts are usually stronger than tinctures. Strengths are expressed as a certain concentration. For example, a 2:1 extract means that one part of the extract comes from 2 parts of the original (or crude) plant.
Tinctures are made by soaking the herb in the appropriate solvent (liquid), usually alcohol or water. This mixture is soaked for a certain period of time. The liquid is then strained or pressed, to yield the tincture. The usual concentration of a tincture is 1 part plant to 5 or 10 parts liquid, expressed as 1:5 or 1:10, respectively. Dosage varies according to the active principles in the herb.
Capsules have made using herbal medicines more convenient. They are generally small gelatin containers for swallowing and holding powdered extracts or oils that might otherwise not taste good. Dosages may be different from one company to the other. Ask your caregiver what may be best for you.
Last Updated: 1/4/2011