Benefiber contains wheat dextrin, which is a form of wheat starch. As a regulating fiber, it helps to relieve occasional constipation and abdominal discomfort without causing diarrhea.* Benefiber Fiber Supplement Benefiber Fiber Supplements Fiber Fiber must have water to work its best. How quickly does benefiber work . Fiber aids in weight loss in two ways: First, it adds bulk so that you feel full fast; For the treatment of constipation, psyllium fibre works by absorbing water from the intestines to produce larger,. The main difference between benefiber and metamucil is the type of fiber they contain: It is available in 20 and 35 servings; Benefiber comes in as a powder. Use it alone or in combination with an eating plan. Ps1000 allows you to lose more weight and reach goals faster than most on weight loss programs. To receive the greatest benefit from this medicine, take it on a daily basis. It is a rich source of dietary fiber and can help relieve cons...