WHEN you take drugs, you want to know what you are getting. So devotees of the herbal antidepressant St John’s wort may be alarmed by a report showing that the concentration of hypericin, the active ingredient in the product, is not always as stated on the label.
A survey of St John’s wort products purchased from Californian health food stores has found that the concentration of hypericin can vary from just 2.9 per cent of what is stated on the label to as much as 114 per cent. And sometimes the majority of the active ingredient is not hypericin itself but a close relative, pseudohypericin (Journal…
