The Blue Herb was a plant native to the Arklay Mountains in the American Midwest. It was capable of producing a compound that could be used to treat small to moderate doses of several venoms and poisons. However, the venom of creatures such as the Yawn and Nosferatu were far too powerful and required their own special medicines.
- Blue Herbs do not appear in Resident Evil 4, where they are replaced by the Yellow Herb due to a lack of poisonous and venomous enemies in the game.
- George Hamilton can use his chemical mixing kit to turn Blue Herbs into recovery medicine which will restore 500 points of a player's health, equivalent to a Green Herb.