Drug vs. Drug

Benefiber vs. Metamucil: Differences, similarities, and which is better for you

Kristi Torres writer headshot By | May 14, 2020

Drug overview & main differences | Conditions treated | Efficacy | Insurance coverage and cost comparison | Side effects | Drug interactions | Warnings | FAQ

Fiber is a key component of a healthy diet. Fiber helps with bowel regularity and colon health. Fiber adds bulk to the stool and holds water, making stools easier to pass. There are other potential benefits to healthy fiber intake such as lower incidences of heart disease, better control of blood sugar, and healthy weight maintenance.

Fiber is found naturally in foods you may eat every day. There are two types of fiber: soluble and insoluble. Soluble fiber can be found in dried beans, oats, oat bran, citrus fruits, and apples, among other foods. Soluble fiber serves to slow digestion and therefore slow the body’s absorption of sugar. Soluble fiber also binds fatty acids and removes it from the body, therefore lowering the low-density lipoprotein (LDL) cholesterol. Insoluble fiber helps hydrate and transport waste through the intestinal tract. This promotes bowel regularity and digestive system health. It is ideal to get your fiber from dietary sources because these foods are rich in other nutrients your body needs. However, if your diet does not contain enough fiber, you may need to take a fiber supplement such as Benefiber or Metamucil.

What are the main differences between Benefiber and Metamucil?

Benefiber is an over-the-counter (OTC) soluble fiber supplement. The active ingredient in Benefiber is wheat dextrin. Benefiber absorbs water in the intestinal tract. This stimulates peristalsis or the repetitive contraction and relaxation of intestinal muscle. While this process ultimately moves intestinal contents, it slows the transit time through the intestine. Benefiber is available as a powder in packets or bulk packaging as well as oral or chewable tablets. There are sugar-free and gluten-free formulations available as well.

Metamucil is an OTC soluble fiber. Metamucil is made from psyllium husks, which come from seeds of an Indian herb known as Plantago ovata. Metamucil works in the same manner as Benefiber, stimulating peristalsis, and slowing intestinal transit. Metamucil is available as a powder in packets or bulk packaging as well as capsules. Some formulations are also sugar-free and gluten-free.

Main differences between Benefiber and Metamucil
Benefiber Metamucil
Drug class Fiber supplement Fiber supplement
Brand/generic status Brand and generic available Brand and generic available
What is the generic name? Wheat dextrin Psyllium
What form(s) does the drug come in? Bulk powder and powder packets, oral and chewable tablets Bulk powder and powder packets, oral capsules
What is the standard dosage? 2 teaspoonfuls 3 times daily in 8 oz glass of water or clear liquid 1-2 rounded teaspoonfuls of powder 3 times daily in 8 oz glass of water or clear liquid
How long is the typical treatment? A few days to indefinite use A few days to indefinite use
Who typically uses the medication? Children and adults Children and adults

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Conditions treated by Benefiber and Metamucil

Benefiber is approved by the Food and Drug Administration (FDA) as a dietary fiber supplement. Due to its ability to add bulk to the stool, it is used off-label, or without FDA approval, as a laxative to treat constipation.

Metamucil is approved as a fiber dietary supplement and in the treatment of occasional constipation. Metamucil’s ability to build bulk in the stool helps produce bowel movements that are easier to pass. Metamucil is also indicated in the reduction of risk of coronary heart disease. This is due to its ability to bind fatty acids and remove them from the body, thereby decreasing LDL cholesterol. Metamucil is used off-label to help control blood sugar in patients with diabetes mellitus. One randomized, controlled trial showed that Metamucil may be beneficial in decreasing symptoms of irritable bowel syndrome as well.

Condition Benefiber Metamucil
Dietary fiber supplement Yes Yes
Constipation Off-label Yes
Reduction of coronary heart disease risk No Yes
Decrease blood sugar No Off-label
Irritable bowel syndrome No Off-label

Is Benefiber or Metamucil more effective?

A clinical review published in 2015 sought to evaluate the health outcomes of regular fiber therapy by comparing commercially available fiber products. Researchers describe that a key difference between dextrin (Benefiber) and psyllium (Metamucil) is that dextrin is readily fermented in the intestinal tract. Once fermented, dextrin loses its water-holding capability and therefore is not an effective laxative. Psyllium is not fermented, and thus becomes a viscous, gel-like consistency and can hold water in the stool throughout the large bowel. This provides a hydrated, bulky stool that can be excreted more easily. Furthermore, the American College of Gastroenterology Chronic Constipation Task Force published findings that psyllium was the only fiber supplement that showed enough clinical evidence to support an indication for chronic constipation.

The American Diabetes Association published a meta-analysis in 2019 evaluating fiber supplements’ effects on glycemic control. Their findings suggested that viscous fibers, like psyllium, showed the greatest effect on glycemic control. Psyllium’s viscous gel formation slows digestion, likely slowing sugar absorption. This effect of slowing digestion also leaves you feeling fuller for a longer period of time, seeming to aid in weight loss.

A randomized, placebo-controlled trial published in 2012 evaluated psyllium’s effects on LDL cholesterol in adolescent males with risk factors for heart disease. Psyllium therapy of just 6 g per day was found to significantly lower cholesterol, specifically LDL, by 6%.

Your healthcare provider will provide recommendations on which type of fiber is best for your gut health.

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Coverage and cost comparison of Benefiber vs. Metamucil

Benefiber is an OTC supplement that is not typically covered by commercial or Medicare insurance. Typical retail packaging for Benefiber would be a 248 g bottle, which can cost as much as $21. If your healthcare provider writes a prescription for Benefiber, a coupon from SingleCare can lower the price to less than $15.

Metamucil is also an OTC supplement that is not generally covered by commercial or Medicare insurance. Common packaging would be a box containing 44 dose packets of Metamucil powder. A coupon from SingleCare would make it possible to get Metamucil for around $17 (but, again, you’d need a prescription).

Benefiber Metamucil
Typically covered by insurance? No No
Typically covered by Medicare? No No
Standard dosage 248 g bottle of powder 1 box, 44 packets
Typical Medicare copay n/a n/a
SingleCare cost $13-$18 $17-$24

RELATED: How to use SingleCare savings with OTC products

Common side effects of Benefiber vs. Metamucil

The most reported side effect of fiber therapy is flatulence or the build-up of gas in the gastrointestinal tract. Adverse events associated with Benefiber and Metamucil appear to be relatively rare, but may also include stomach pain (cramping) and bloating. Frequency may be hard to define due to the variations in lengths of therapy as well as dosing. Patients taking Metamucil have reported nausea and vomiting, as well as asphyxiation, or choking. Rarely, hypersensitivity reactions may occur.

The following list is not intended to be a complete list of possible side effects. Please consult a pharmacist or healthcare provider for a complete list of possible side effects.

Benefiber Metamucil
Side effect Applicable? Frequency Applicable? Frequency
Flatulence Yes Not defined Yes Not defined
Abdominal discomfort Yes Not defined Yes Not defined
Bloating Yes Not defined Yes Not defined
Nausea n/a n/a Yes Not defined
Vomiting n/a n/a Yes Not defined
Asphyxia n/a n/a Yes Not defined

Source: Metamucil, Benefiber

Drug interactions of Benefiber vs. Metamucil

There are no known drug interactions with either Benefiber or Metamucil. Bulk-forming fiber like Metamucil may affect how other medications are absorbed. The manufacturer recommends that you take your Metamucil two hours before or two hours after your prescribed medication.

Warnings of Benefiber and Metamucil

It is important to take Benefiber and Metamucil products with adequate amounts of fluid. Taking fiber therapy without adequate fluid intake can lead to esophageal blockage and choking. Do not take these products if you have difficulty swallowing. If you experience chest pain, vomiting, or difficulty in swallowing or breathing, seek medical attention immediately.

If you experience constipation for more than seven days or if you experience rectal bleeding while taking Benefiber or Metamucil, contact your healthcare provider immediately.

Benefiber and Metamucil powders are gluten-free, though some other products made by these brands may not be. Patients with celiac disease should read the label and consult a healthcare professional to ensure the fiber product they have chosen is safe.

Frequently asked questions about Benefiber vs. Metamucil

What is Benefiber?

Benefiber is an OTC soluble fiber product indicated for dietary fiber supplementation. Benefiber can be used as a daily fiber supplement and is available in powder form as well as oral and chewable tablets.

What is Metamucil?

Metamucil is an OTC soluble fiber product indicated for dietary fiber supplementation. It can also be used as a daily fiber supplement and is indicated to treat occasional constipation, as well as to decrease risk factors for coronary artery disease. Metamucil is available in powder form as well as oral capsules.

Are Benefiber and Metamucil the same?

Benefiber and Metamucil are both fiber supplements, but they are not the same. Benefiber contains wheat dextrin and is only approved as a fiber supplement. Metamucil contains psyllium, and in addition to being an approved fiber supplement, is also approved as a bulk-forming laxative. It also binds fatty acids to help lower LDL cholesterol.

Is Benefiber or Metamucil better?

Metamucil has been shown to be a more effective laxative due to the fact that it is not fermented in the human bowel. This allows it to hold water throughout the intestinal tract and slows digestion. Slower digestion has been shown to help with glycemic control and weight loss as well.

Can I use Benefiber or Metamucil while pregnant?

With adequate fluid intake, both Benefiber and Metamucil are safe to take when pregnant as they are not absorbed into the bloodstream.

Can I use Benefiber or Metamucil with alcohol?

Alcohol use with Benefiber is not contraindicated, though alcohol should always be consumed in a safe manner. When choosing a fluid to mix with your powder fiber supplement, alcohol is not recommended.

Which fiber supplement is best?

Metamucil has been shown to have more health benefits overall versus Benefiber. In addition to being a fiber supplement, Metamucil is a proven bulk-forming laxative. It also has been shown to reduce heart disease by reducing LDL cholesterol. Its effect on slowing digestion time helps maintain glycemic control and may aid in weight loss.

What are the side effects of taking Benefiber?

Benefiber may increase flatulence or gas build up in the intestinal tract. It may also increase the incidence of abdominal cramps or discomfort and bloating.

Is it safe to take Metamucil every day?

It is safe to Metamucil for gut health every day as long as you consume adequate fluid. Stop taking Metamucil and call your doctor if you experience constipation for more than seven days or have rectal bleeding.

Should you take fiber before or after a meal?

You can take your fiber before, during, or after meals. When taking fiber as an adjunctive therapy for diabetes, one study suggests taking just before starting your meal to help slow digestion and decrease appetite.