Metamucil can be taken at any time of the day as long as it is accompanied by at least 8 ounces of water, according to Metamucil's official website. Patients who are consuming Metamucil to feel less hungry should consume the fiber supplement before eating.
Since Metamucil contains bulk-forming fibers, the product should be consumed two hours before or after other medications, warns the official website. Metamucil can be taken up to three times each day at mealtimes as a fiber supplement. It can also be used occasionally to relieve constipation. Persons taking Metamucil to lower cholesterol or help maintain healthy blood sugar levels should consult with their physician for the appropriate dosage.