Metamucil Products for Constipation

Medically Reviewed by Laurel Riemann, PharmD on December 04, 2025

Metamucil products are used to treat constipation. Constipation is when it is hard for you to poop or you poop less often than what is normal for you.

Metamucil products are fiber laxatives. Most Metamucil products contain a type of fiber called psyllium husk that makes your poop bulkier and softer, which can help poop pass more easily. Some Metamucil products contain other types of fiber.

Some Metamucil products may also contain certain vitamins, probiotics, or prebiotics. Both probiotics and prebiotics can help support your digestive system. Probiotics provide your gut with “good” bacteria. Prebiotics are a source of food for your gut bacteria.

Most Metamucil products are for adults and children as young as 12 years old. Some Metamucil products may be taken by children aged at least 4 years under adult supervision.

Note: The FDA has not reviewed Metamucil dietary supplements for safety and effectiveness, and they are not approved by the FDA. Learn more about dietary supplements here.

Metamucil products are generally safe to use. Side effects may vary depending on the ingredients in the specific product you are using. When you first start taking Metamucil, some possible side effects can include bloating and changes in your bowel habits. To help your body adjust, it is best to start with a small amount and slowly increase the dose of Metamucil you take (based on the directions of the product you are taking).

Stop taking the medicine if you develop a rash or hives. Get medical help right away if you have signs of a serious allergic reaction, such as trouble breathing or swelling of the face, lips, or throat.

Before taking Metamucil, talk to your health care provider if you have stomach pain, nausea, vomiting, or a change in your popping pattern that has lasted two weeks or more.

Taking a Metamucil product may cause you to have a bowel movement in about 12 hours to three days. Carefully read the directions of your Metamucil product. You may need to drink a certain amount of water after taking a dose, for example.

Metamucil products contain fiber, which may affect how other medicines work. If you are taking Metamucil with other medicines, take Metamucil two hours before or two hours after you take your other medicines.

Soluble fiber, such as what is found in Metamucil products, binds cholesterol in your gut. The bound cholesterol gets removed from your body via bowel movements (poop). Eating 5-10 grams of soluble fiber each day can help to lower a type of bad cholesterol called low-density lipoprotein (LDL) cholesterol. If you want to take Metamucil to help support your heart health, talk to your health care provider to see if Metamucil may be right for you.

If you use a medicine to control your blood sugar levels, talk with your health care provider before using a Metamucil product. Some Metamucil products are sugar-free, and some are sweetened with Stevia or aspartame.

Stop using a Metamucil product if you have constipation that lasts seven days or more or rectal bleeding. You may have rectal bleeding if you notice blood in your poop or toilet paper used to wipe yourself.

Throw away any unused or expired Metamucil. Do not pour Metamucil down the sink.

Do not take a Metamucil product if you have trouble swallowing. If your Metamucil product is a gummy, fully chew the gummy before swallowing. If your Metamucil product is a powder, mix the powder with at least 8 oz (full glass) of a cool/cold liquid. Do not mix with hot beverages. Adding Metamucil powder to hot beverages causes it to gel more rapidly. A thick liquid could cause you to choke.

If you do not drink enough fluid with a Metamucil product, the product can swell and block your throat. Get emergency help after taking a Metamucil product if you have trouble swallowing or breathing or if you have chest pain or vomiting.

There may be side effects, additional warnings, and interactions with other medicines that are not listed here. These may vary depending on the combination of ingredients in the specific Metamucil product you are using. Always check the label before taking any over-the-counter medicine. Do not take more than the recommended dose. Talk to your doctor or pharmacist about your health conditions and other medicines to help determine which products are safe for you.

Metamucil products come as powders, gummies, and capsules and are gluten-free. But Metamucil Thins, which are snacks that contain fiber, do contain gluten.

Gummies

Metamucil Fiber Gummies

  • Contain prebiotics
  • Have 5 grams of fiber per serving

Metamucil Coated Fiber Gummies

  • Have a crystal coating
  • Contain prebiotics
  • Have 5 grams of fiber per serving

Metamucil Fiber + Probiotics Gummies

  • Contain probiotics and prebiotics
  • Have 5 grams of fiber per serving

Metamucil Kids Fiber Gummies

  • No added sugar and mixed berry flavor 
  • Contain prebiotics
  • Can only be given to children at least 4 years of age under adult supervision
  • Have 5 grams of fiber per serving

Metamucil Fiber + Vitamins Gummies

  • Contain vitamins C, D, and B12
  • Contain prebiotics
  • Have 5 grams of fiber per serving

Powder

Metamucil SuperGreens Digestive Blend Powder

  • Sweetened with Stevia
  • No added artificial dyes

Metamucil Premium Blend Sugar-Free Powder

  • Sweetened with Stevia

Metamucil 4-in-1 Fiber Sugar-Free Powder

  • Sweetened with aspartame or as unflavored (no sweetener)
  • Available as flavored on-the-go single-use packets 

Metamucil 4-in-1 Fiber Real Sugar Powder

  • Available as unflavored and flavored
  • Available as flavored on-the-go single-use packets

Metamucil Fiber + Vitamins Sparkling Fiber Powder

  • Sweetened with Stevia
  • Sparkles when mixed with water
  • Contains vitamins C, D, and B12

Metamucil Fiber + Collagen Rejuvenation Blend Powder

  • Contains collagen
  • Sweetened with Stevia

Metamucil Clear Fiber Blend

  • Unflavored
  • Mix in any beverage or soft food like yogurt or smoothies
  • Contains prebiotics

Capsules

Metamucil 3-in-1 Daily Fiber Capsules

  • Sugar-free 
  • Sit upright and drink at least 8 oz of liquid while taking this product

Fiber Thins

Metamucil Fiber Thins

  • 5 grams of fiber and 100 calories per serving
  • Individually wrapped for on-the-go use
  • Drink at least 8 oz of liquid after eating the Fiber Thin