Metamucil Dosages: Your GoodRx Guide

Many people don't get the fiber they need. And this can lead to constipation. Fiber helps make your stools larger and easier to pass when going to the bathroom. Many times, increasing your intake of fiber through diet or supplements is all a person needs to get things moving again. 

Metamucil (psyllium) is a commonly purchased over-the-counter (OTC) bulk-forming laxative. It provides soluble fiber and can help “bulk” up your stools to help cause a bowel movement. But with any laxative, knowing how much to take is essential. So how much Metamucil should you take for constipation? And is there a safe Metamucil dosage for kids? 

What Metamucil dosage forms are available?

Metamucil isn’t a single medication but rather a line of products. All of them contain psyllium. Available Metamucil dosage forms include:

• Powder

• Oral capsules

• Wafers

• Gummies

Only a few of the powder forms of Metamucil have an OTC medicine label for constipation relief:

• Metamucil orange powder packets

• Sugar-free Metamucil orange powder packets

• Metamucil orange 48-dose powder bottle

• Sugar-free Metamucil orange 48-dose powder bottle

All other Metamucil products are considered dietary supplements. They’re intended to be used as a daily fiber supplement and aren’t labeled to help with constipation. Because our focus is on Metamucil dosages for constipation relief, we’ll only discuss the products that are labeled as laxatives.

What’s the typical Metamucil dosage for adults?

The typical adult Metamucil dosage for constipation is 3.4 grams (1 packet or 1 tablespoon), mixed with 8 ounces of liquid, up to 3 times a day. It’s best to start with one dose per day and then increase as needed.

Here are some tips for preparing your Metamucil dose:

• If you’ve purchased a bottle of Metamucil powder, use a baking spoon to measure out doses (not a spoon from your silverware drawer).

• Place your serving of powder into an empty cup.

• Mix the powder with 8 ounces of water or another cool liquid. Orange juice can be a good option, since Metamucil is an orange-flavored powder.

• Stir briskly to help avoid creating clumps.

• Drink the entire mixture immediately. Don’t save for later.

• If the mixture starts to thicken before you finish drinking it, add water (or other liquid) and stir again. Then, finish consuming your dose.

It’s important to add the minimum 8 ounces of liquid when preparing Metamucil. If you don’t use enough water, it can raise the risk of choking while swallowing the mixture. Keep in mind that you can always add more than 8 ounces of liquid for lighter flavor and a thinner drink.

Generally, you should experience a bowel movement in 12 to 72 hours (3 days) after starting Metamucil. If you don’t have any bowel movements while taking Metamucil or are constipated for more than 7 days, contact your provider.

What’s the typical Metamucil dosage for children?

The children’s Metamucil dosages are as follows:

• Ages 12 years and older: Mix 3.4 grams (1 packet or 1 tablespoon) with 8 ounces of water or other cool liquid up to 3 times a day.

• Ages 6 to 11 years old: Mix 1.7 grams (½ packet or ½ tablespoon) with 8 ounces of water or other cool liquid up to 3 times a day.

• Under 6 years old: Ask your child’s healthcare provider before giving.

Be sure to follow the preparation tips in the above section when mixing a dose of Metamucil for your child. Keep in mind that your child must drink 8 ounces of fluid immediately after you mix it. Using less than 8 ounces of liquid can be a choking hazard. Not all children may be able to drink this much in such a short time.

Stop giving your child Metamucil if they continue to be constipated for longer than 7 days or have no bowel movements at all within 3 days of starting it. These could be symptoms of a blockage in the intestines.

Keep in mind that laxatives often aren’t a first-choice option for constipation relief in children. It’s always best to check with your child’s provider before giving Metamucil — even if there’s a dose for their age on the package.

Are there any dosage adjustments for certain people?

There are no specific dosage adjustments needed for Metamucil based on health conditions, such as kidney or liver problems. But there are people who may not be able to take the medication.

Speak with your healthcare provider about Metamucil first if you or a loved one have:

• Trouble swallowing

• Phenylketonuria (PKU)

• Rectal bleeding

• Problems with getting out of bed

• Fluid restrictions like in heart failure

• A health condition that affects your cognitive function, such as dementia

You should also contact your provider first if you’re pregnant. While Metamucil is usually considered safe to take during pregnancy, everyone’s risks are unique. Your provider may prefer you try something else for constipation relief.

Metamucil can interact with many medications, preventing them from being properly absorbed. Share your current medication list with your provider and pharmacist when starting Metamucil. You may need to take it at a certain time of day to avoid interactions.

What happens if you miss a dose of Metamucil?

If you miss a dose of Metamucil, take it when you remember, unless it's too close to your next dose. If it’s almost time for your next dose, just skip it. Never double up on doses or take extra Metamucil. This can worsen constipation.

What should you do if you take too much Metamucil?

If you take more Metamucil than recommended, you may experience more side effects than usual. This includes bloating, stomach cramps, and gas. But in some cases, too much Metamucil can cause severe constipation and bowel obstructions (when food and stool can’t move through the intestine).

If you or a loved one takes too much Metamucil, contact a healthcare provider. You can also call Poison Control at 1-800-222-1222 for guidance. If you’re experiencing severe stomach pain, nausea, and vomiting in addition to constipation, seek medical help.

How to save on Metamucil

There are many ways to save on Metamucil, which is available as both a brand-name and generic medication. If your healthcare provider writes you a prescription for OTC Metamucil, GoodRx may be able to help you save. Generic Metamucil’s price at certain pharmacies is as low as $ with a free GoodRx coupon.

Why trust our experts?

Written by:

Timothy Aungst, PharmD

Timothy Aungst, PharmD, has worked in pharmacy practice for the past decade with different roles and responsibilities. He has served as an associate professor of pharmacy practice for almost a decade, a clinical pharmacist in outpatient cardiology management, and now in home healthcare.

Edited by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

Reviewed by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

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