Hello Cori.
The answer depends on whether you know your RBC magnesium level. It is a simple blood test that tells how much magnesium is inside the cells. Since magnesium is not found in high amounts in most foods and the daily value is 400 mg for women, the recommended 2 tabs or caps twice a day is a good daily dose. You can read more about RBC magnesium in the article Magnesium, Testing for Deficiency, which can be found on the Fibro-Care product page. Hope that helps!