All Biorepair products are based on microRepair®, a patented active ingredient based on biomimetic hydroxyapatite, which is able to bind to tooth enamel and repair it, creating a protective barrier very similar to natural enamel. As it has these special features, microRepair has a rather particular consistency and is not completely soluble in liquids.
This is why our mouthwash looks milky, instead of transparent like other mouthwashes available on the market.
This aspect is due to the presence of microRepair®, which also has a tendency to drift to the bottom of the bottle. You could compare it to fresh orange juice: the 100% natural variety contains pulp that settles on the bottom, while juice which is not wholly natural is filtered and transparent. So here too, the need to "shake well before use" is a genuine indication of quality.