Metamucil is a fiber supplement made from the seed grain psyllium. Psyllium is also available as generic dietary fiber supplements sold in many pharmacies. A daily intake of about 10 grams or about 2 teaspoons of psyllium was found to lower LDL by an average of about 10 percent. Taking a daily fiber supplement will not only help keep you regular. It will also lower your risk of developing cardiovascular disease.