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Herbal drugs and extracts

Herbal drugs are gained from plant material and can be used as drugs in the medicine. This use is on the one side based on scientific studies and on the other side based on a century-long experience with the use of medicinal plants. Herbal drugs can be used either to relieve symptoms and thus supporting the conventional medicine or to control causes of diseases.

The effect of herbal drugs based on one to a few main active compounds within the plant. They can be isolated by suitable extraction procedures. This insulated main active compound may have a considerably weaker effect than the herbal drug. The reason for this can be supportive effects of adverse substances in the plant, which themselves are not effective.

Example of a herbal drug: Valerian from Köhlers Medizinal Pflanzen

Some good known examples for herbal drugs like essential oils or coffee are used in daily life , but have no use as a medicament.

Plant collecting

The collection of plant drugs required a profound knowledge and experience with the respective plants. The ingredients vary by location and are subject to fluctuations. Following factors play a significant role:

  • Genetic predetermination
  • Environmental influences, such as
    • Nutrient supply
    • Soil
    • Light
    • Water
  • Harvest time

Because of these complexities, it is usually better to purchase herbals and plant extracts in retail.

For the determination of the general harvest time the following rules can be formulated:

Part of plant harvest time
Fruits and seeds when the fruit is ripe
Roots and rhizomes in early spring before the plants sprout or in late autumn, when the leaves begin to fall
Flowers mostly before full bloom or in bud stage
Leaves, Herb in full bloom or a bit earlier
Bark spring and summer

Plant parts

Depending on the herbal drug different parts of the plant are used. The active ingredients are for example in one plant especially in the root, at the other in the flowers. This knowledge leads to the targeted use of the right parts of plants. The following table gives an overview of used plant parts:

English name Latin name Example
Root Radix Valerian root, Ginseng
Rootstock Rhizoma Ginger
Bark Cortex Willow bark
Flower Flos Lime blossom
Fruit Fructus Caraway
Seeds Semen Strychnos nux-vomica, Tonka bean
Leaves Folium Stevia leaves
Herb Herba Goldenrod

Processing of plants

The processing of herbal drugs and extracts are important to improve the spectrum of the agent and leads to a preservation and detoxification of the drug and a better presentation of the medicine can be achieved.

In fresh plant material (intentional) fermantation can take place before processing. As a result, desired ingredients are specifically enriched, or toxic ingredients metabolized. Fermantation is well known from the roasting of coffee or tabacco.

Fresh plant material is often used for the production of essential oils. Due to an impending fermentation plants are dried to protect them from this. In modern process the harvested plants are dried in a hot air stream to 60°C for several hours or days. The drying reduces the weight of the herbals by the withdrawal of water in some cases considerably (up to 15% on flowers), with 10% to 20% of the dried plant is still water. Seed must not be dried.

Traditional processing

In addition, there are traditional drying methods such as used in traditional Chinese medicine. Here, the plants are dried, for example over fire. Also the boiling in a liquid such as wine, vinegar or honey with subsequent drying is recommended to remove toxic ingredients. In addition, plant drugs are calcined. In this process any water is removed at high temperatures. The drugs are therefore brittle and powdery.

In addition to these drying process plants can be roasted, boiled and cooked in steam. Each of these processes must be adapted to the plant, otherwise the active ingredients of the plant may are lost.


Herbal drugs and extracts may be used differently depending on their processing. The most famous usage is the tea infusion, in which, however, different results can be generated by different parameters (water temperature, exposure time, amount of drug). In addition to that herbal drugs can be drunk as juice, syrup, wine or spirits (by alcoholic extraction).

Also known is the use of herbal drugs and extracts, as an ointment or gel. The preparation of ointments and gels is more complex and requires more detailed knowledge of the contents of ointments.

Dried herbal drugs and extracts can be processed into powder or compressed into pills.

In addition, plant drugs and extracts can be used as tinctures, herbal baths and compresses.

herbal_drugs_and_extracts.txt · Last modified: 10.12.2014 by naturalproductswiki