St Johnswort, Uses and Doses

Can you please send me any information you have on St. John's Wart regarding its uses and the amounts that you can take.

St. John's Wort, Hypericum perforatum has anti-depressant, anti-viral, anti-inflammatory and relaxing properties.
Internally, it is used in depression, anxiety and pain. The maximum daily dosage is 4 ml of tincture, or 4 grams of dried herb 3 three times a day.
Externally, an oil made by steeping the flowers in olive oil is effective in calming, cleansing and healing wounds and burns, and relieving joint and muscular pain.