A healthy genital area is dominated by lactic acid bacteria that provide an acidic environment in the vagina. These can for various reasons vary in numbers and can affect the environment in the vagina. When you use ellen® probiotic tampons, you add the same natural lactic acid bacteria that are normally found in a woman's vagina and help maintain a normal vaginal pH level. Use probiotic tampons as much as you want during your period. The body only absorbs so much lactic acid bacteria that it needs. For optimal benefit, at least 3 tampons per day are recommended.