They have never, to my knowledge, been formally tested in a public medical study, but anecdotal evidence indicates that they work. Every natural food store and vitamin emporium carries a number of brands that you won't find marketed in mainstream supermarkets. My only advice there is to watch the dosage carefully. Many of these pills come in dosages too small to be of any real use or mixed in with other dietary enzymes that may or may nor have value to you. I would stick with pills that contain at least 1750 FCC units.
Some pills have their strengths measured in milligrams.
As raw lactase comes in both a pharmaceutical strength and a food grade strength, it is harder to determine FCC unit equivalents in those cases, but 125 mg should be effective. Here's where they pay off. The A. oryzae lactase is designed to work at a certain level of acidity. This makes sense because the stomach is awash in acids that are used to break down food for digestion. But here's the kicker.