Nature's Way St. John's Wort - Standardized Extract has the most-recommended dose and potency of St. John's Wort Extract - 300 mg per capsule of a 0.3 % extract. You also get energizing spirulina and antioxidant rich rosemary for synergistic enhancement of St. John's Wort's mood boosting effects. Nature's Way St. John's Wort can be a great way to support a good mood but can take a few weeks of daily use before the full effects are experienced.