Use a pearl size drop twice a day to remove coffee, tea, tobacco, red wine, and food stains to see fast results. Calprox works by gently dissolving the protein pellicle, a thin layer of protein that forms on the surface of teeth, to which plaque, bacteria, and stains adhere. Safely removing the stained pellicle without the use of harsh abrasives, like Silica, leaves the teeth looking and feeling cleaner for a longer period of time. Made in the USA.