St John's Wort (Hypericum perforatum) is a perennial plant native to many parts of the world, including European countries and the USA, and in the UK, it is now one of the most recommended herbs. Cautions: -This product is not recommended for pregnant or lactating women. -Patients taking any prescribed medicines should check with their doctor or pharmacist before taking St. John's Wort as it may affect the way that they work.