What is Metamucil: Uses, Warnings & Interactions

Follow the instructions on the Metamucil label. Avoid taking larger doses or taking fiber supplements more often than recommended.

If you are using this medicine under the advice of a doctor, follow the doctor’s instructions.

The recommended dose is three servings per day.

What constitutes a serving depends on the product.

• For Metamucil powders, a single serving is either one to two teaspoons, two tablespoons, or a single packet, depending on the product and the purpose

• A single dose of Metamucil capsules consists of two to five capsules, depending on the purpose

• For Metamucil gummies, a single serving is three gummies.

• For Metamucil wafers, a single serving is one packet of two wafers.

The powder can be measured with a kitchen measuring spoon and mixed with eight ounces of water or other liquid.

• Drink the mixture right away because the fiber will settle at the bottom.

• Never swallow the powder dry.

Always drink 8 ounces of water or other liquid when taking Metamucil.

When first starting Metamucil, use low doses. Metamucil can initially cause loose stools and bloating when first taken.

• Only take one dose of capsules per day when starting Metamucil capsules.

• The manufacturer suggests one gummy per dose when people first start.

If you forget to take Metamucil, take it when you can. 

Don’t take a double serving or a bigger serving if you forget to take a Metamucil serving.

You should not use Metamucil if you have ever had an allergic reaction to psyllium or any other ingredients in a Metamucil product.

Psyllium can cause serious problems in people with certain conditions. Some healthcare professionals believe that psyllium should never be used by people with those conditions. To be safe, do not take psyllium until you’ve talked to a doctor if you have:

• Bowel blockage

• Difficulty swallowing

• Esophageal stricture

Tell any doctor or other healthcare provider who treats you that you are using Metamucil.

Before using Metamucil, ask a doctor for medical advice if you have:

• Recent abdominal pain, nausea, or vomiting

• A sudden change in bowel habits lasting for two weeks or more

• Other stomach or intestine problems

• Kidney disease

Stop using Metamucil and call a doctor if you experience:

• Rectal bleeding

• Diarrhea that lasts longer than one week

Sugar-free Metamucil may contain aspartame. People with phenylketonuria could have a severe reaction if they take these products.

Always drink eight ounces of water when taking Metamucil. Without drinking water, the fiber in Metamucil could form a lump in the throat and cause choking.

If you are taking prescription medications, ask the prescribing doctor for advice before taking any Metamucil product. 

Tell any healthcare professional who prescribes new drugs that you are taking Metamucil.

Metamucil could interfere with the body’s ability to absorb some oral drugs, making them less effective. A doctor may advise you to take certain prescription drugs two hours before or two hours after taking Metamucil.