Description clinical trials have shown that St John's wort can assist significantly in the management of mood swings, which supports its traditional nervine uses. In fact, it is one of the best-known herbs for treating nervous conditions. The therapeutic dose helps relieve symptoms of anxiety, nervous unrest, restlessness and sleeplessness. Contains St John's wort (Hypericum perforatum) herb dry: 2 g per bag 1.1 g per 5 mL level metric spoon Dosage: Infuse one teabag (or two 5 mL level metric teaspoons) with one cup of boiling water, steep and cover for ten minutes. Adults can take one cup twice daily. Children from 6 to 12 years can take one cup daily.