|
Page: Dosage and Formulations
Main article
| Home > Alternative Health > Dosage and Formulations |
The dosage and content of St John's wort preparations vary greatly between formulations, because of variability in the plant source and preparation processes. The doses of St. John’s wort extract used in clinical trials generally range from 350 to 1800 mg daily (equivalent to 0.4 to 2.7 mg hypericin depending on the preparation). Because of the variable nature of herbal medicines, the clinical trial results using one product cannot be extrapolated to other products containing the same herb (just as a prize winning wine is not the same as everything else made from grapes). Only a handful of products made from St John's wort have been used in clinical studies (for example, Li 160 and Ze 117).
The recommended dosage for various forms of St John's wort as recommended by the British Herbal Medicine Association Scientific Committee (1983) are as follows:
* dried herb: 2-4 g or by infusion three times daily
* liquid extract 2-4 mL (1:1 in 25% alcohol) three times daily
* tincture 2-4mL (1:10 in 45% alcohol) three times daily
In markets where standardised extracts are not available, the content of marketed products can vary widely. Some brands of over-the-counter St. John's wort can have a totally different chemical profile than others. The same can even be true of two dosage units from different batches of the same brand. Even where extracts are standardised it is debatable whether using hypericin as the standard is useful, since other constituents including hyperforin are biologically active.
As with other antidepressants, Hypericum should be taken for at least four weeks before its effectiveness can be properly assessed.
|
Important notice:
The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other
qualified health provider with any questions you may have regarding a medical condition.
|