FCC ALU and LU are both units of measurement for lactase activity, and are used somewhat interchangeably, depending on the type of lactase and the environment in which it is most active. For types of lactase designed to act on lactose in the stomach, an acidic environment, FCC Lactase Units, which are sometimes called “Acid Lactase Units” (FCC ALU) are the preferred unit of measurement.
Our Lactase Drops, which are designed to act on lactose in a more neutral pH environment (outside of the stomach/directly in foods), use Lactase Units (LU) (more specifically “Neutral Lactase Units”). These units still convert 1:1, i.e. the definition of one lactase unit in either environment is the same in terms of activity – but the pH in which the particular lactase compound exhibits optimal activity can help determine which unit is used in labeling.
7 drops of Lactase Drops contain 750 LU. Each drop contains 107 LU.
While the two units of measurement are often used interchangeably, and it is possible to say that each drop of Lactase Drops contains 107 FCC ALU. However this may be an inaccurate statement since there is no testing to prove that Lactase Drops would exhibit the same activity in an acidic environment, where FCC ALU would be appropriate to use.