The clove oil bottle doesn't give any hint at the usage. It says for aromatherapy. For other uses, see a clove oil website for dilution instructions. I guess they wan't to protect themselves legally in case someone has a problem. The wormwood says take 10-20 drops 3 times a day. I am taking 10 drops 3 times a day. It doesn't say how long someone should take it though. The black walnut extract says 28 drops 3 times a day, which is what I am taking. The wormwood isn't just for parasites though. It is great at fighting candida, and helps improve digestion.