This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
Dandelion, Taraxacum officinale. The root is official in the U. S. and numerous other countries, the leaves in five countries. Another of the Com-positae that is a tonic bitter. See "Gentian" for a discussion of the bitters. This drug has been erroneously classed as a cholagogue (Wilcox). It is, however, a mild laxative in full dosage. It has also been classed as a diuretic. As a matter of fact, taraxacum is available only as a simple bitter, in which direction it serves very well; but the dose, to be effective (extract 15 grains, fl. 2 1/2 fluidrachms), is large and may occasion flatulence and diarrhea. Furthermore, the root loses. activity in drying. The most rational preparation is the Succus Taraxaci of the British Pharmacopeia, and prepared by adding alcohol to the fresh juice. The dose of this is 1 to 2 fluidrachms.
Physicians who prescribe certain proprietary viniferous tonics containing taraxacum in ludicrously small quantities, usually also carrying a little phosphoric acid, will do better if they write for tr. nux vomica, dilute phosphoric acid, compound tr. carda-mon, syrup of orange, and water (no wine). If the patient needs alcohol, compound tr. gentian may displace the water.