St. John’s Wort works best if taken twice a day. In the third and fourth weeks of your treatment, take 300 mg in the morning and 600 mg in the evening. In the fifth week, consider increasing the dose to 600 mg twice a day. Like all antidepressants, this alternative medicine can take 4-6 weeks before notice its effects and benefits. Consult your doctor for more information on the use and dosage.