Citrucel vs. Metamucil: Similarities & Differences

Citrucel (methylcellulose fiber) and Metamucil (psyllium fiber) are popular over-the-counter (OTC) fiber supplements. Both are classified as bulk-forming laxatives used to relieve occasional bouts of constipation.

The two contain different active ingredients: Metamucil contains psyllium fiber, while Citrucel contains methylcellulose fiber. Both are considered natural fiber types, and both options can effectively ease constipation. People also take Metamucil or Citrucel to boost their fiber intake.

Raising the amount of fiber in your diet is associated with multiple health benefits, such as healthy cholesterol levels and reduced risk of cardiovascular disease. However, not all fiber supplements are proven to relieve constipation.

This article will provide an in-depth analysis of Citrucel vs. Metamucil, examining their specific uses, effectiveness, dosing requirements, side effects, and more.

What Is Constipation?

Constipation, technically defined as having fewer than three bowel movements a week, occurs when your bowel movements become less frequent and stools become difficult to pass.

Primarily, it occurs due to changes in diet or routine or due to inadequate intake of fiber. The longer you go before you poop, the more difficult it becomes for poop to pass.

Occasional constipation can often be relieved by changing your diet, exercising, or drinking more water.

However, when lifestyle modifications aren’t enough, OTC laxatives, such as fiber supplements, can help your bowels function effectively again.

Specifically, one treatment for constipation is bulk-forming laxatives. Bulk-forming laxatives increase the size of your stools by helping them retain fluid, encouraging your bowels to push out the stools.

What Is Citrucel?

Citrucel is a brand-name OTC medication. It contains the active ingredient methylcellulose fiber. It is Food and Drug Administration (FDA)-approved to relieve occasional, irregular constipation.

Citrucel should not be taken every day for chronic (ongoing) constipation. Constipation lasting more than seven days could indicate a more serious health problem.

Citrucel comes in two forms: an oral tablet and a powder to be dissolved in liquid. Both forms of Citrucel are FDA-approved for adults and children 6 or older. Consult a healthcare provider before giving Citrucel to children younger than 6.

How Does Citrucel Work?

Citrucel contains methylcellulose, a soluble fiber found in plants. The human body cannot digest methylcellulose fiber, so it stays intact in your intestines and does not ferment.

There, Citrucel works by increasing the “bulkiness” of your stool. It also causes more water to enter the bowel. Stools that are hard and dry are more challenging to pass.

Additionally, Citrucel produces more complete and regular bowel movements. A bowel movement occurs within 12 to 72 hours after starting Citrucel.

Individual results can vary when it comes to relieving constipation with Citrucel. In some cases, one dose of Citrucel is enough to produce a bowel movement.

However, it may take longer to experience relief—up to several days of taking Citrucel powder or tablets multiple times per day. Be sure to follow the instructions on the product label or from a healthcare professional.

What Is Metamucil?

Metamucil is an OTC bulk-forming laxative used for relieving occasional or irregular constipation. Metamucil contains the active ingredient psyllium husk, which is a type of natural, soluble fiber.

Metamucil powder is to be dissolved in liquid. It is FDA-approved for relieving constipation in adults and children ages 6 years and older. Like Citrucel, consult a healthcare provider before giving Metamucil Orange Powder to children younger than 6.

Note that the manufacturer of Metamucil currently sells multiple different products under the Metamucil brand. Many products in the brand’s lineup are now classified as dietary supplements and contain different ingredients.

However, this article focuses on the original versions of Metamucil with “Drug Facts” labels on the container. These include:

• Metamucil Orange Powder (psyllium fiber)
• Metamucil Orange Powder Sugar-Free (psyllium fiber)

You can consult a pharmacist or healthcare professional to help you select the right product.

How Does Metamucil Work?

Metamucil and Citrucel work differently. Instead of remaining undigested and intact like Citrucel, Metamucil dissolves in the gut.

The dissolved fiber creates a gel-like coating on the intestinal wall, which helps stool exit the bowel more easily. Psyllium fiber also helps soften stools, making them easier to pass.

Metamucil typically causes a bowel movement within 12 to 72 hours after the first dose. The effects of Metamucil last for around eight hours, at which point a follow-up dose may be taken if you still haven’t had a bowel movement.

A key difference from Citrucel is that many healthcare providers commonly recommend Metamucil as a safe and effective option for long-term chronic constipation.

However, if you experience constipation over seven days while using Metamucil, see a healthcare provider before continuing therapy.

Prolonged constipation could indicate a severe medical concern, so it is essential to see a healthcare provider to rule out underlying causes before taking long-term Metamucil.

Dosage Comparison

The following table shows the differences and similarities between the dosage forms, strengths, and recommended doses of Metamucil versus Citrucel for adults and children.

However, depending on the individual, a healthcare provider may recommend a different dosage:

Which Is More Effective?

No studies have directly compared the effectiveness of Citrucel and Metamucil for constipation. Metamucil generally has more evidence supporting its overall effectiveness for maintaining regularity.

However, the two products are expected to work similarly well for a simple case of occasional constipation.

As such, other factors may be better determinants of which product a person chooses. For instance, someone may dislike the orange flavor of the powders and prefer to take Citrucel tablets instead.

Citrucel (methylcellulose) powder tends to dissolve in water more completely than Metamucil (psyllium) powder, which some people may prefer from a texture perspective.

Other factors to consider when deciding between Citrucel and Metamucil are the potential side effects, precautions, and drug interactions. 

Many OTC fiber supplements are available. Choosing one can be confusing or overwhelming.

When you’re looking for a fiber product to relieve constipation, select a product that contains psyllium or methylcellulose fiber as one of the active ingredients. A pharmacist or healthcare professional can help you.

Side Effects & Safety

Generally, Citrucel and Metamucil cause relatively few side effects. When using either medication, possible side effects include:

• Stomach cramps
• Minor bloating
• Gas

Metamucil is more likely to cause bloating and gas than Citrucel. To help minimize bloating and gas with Metamucil, start with just one daily dose, then work up to three doses if necessary.

No known severe side effects have been reported with Citrucel or Metamucil. However, constipation can sometimes signify a more serious health problem.

Stop taking Citrucel or Metamucil and contact a healthcare professional if you develop the following symptoms:

• Severe stomach pain
• Constipation lasting more than seven days
• Rectal bleeding
• Vomiting
• Allergic reaction

In addition, Citrucel and Metamucil powders may lead to choking if not mixed with enough liquid. Mix either product with at least 8 ounces (oz) of water or other liquid.

If the mixture seems too thick, add more water if you’d prefer a thinner consistency. Continue drinking plenty of fluids throughout the day to help promote bowel regularity.

Precautions

People should not take Citrucel or Metamucil if they have trouble swallowing. Before taking Metamucil or Citrucel, talk to a healthcare provider if you have the following:

• Sudden changes in bowel movements that last for two weeks or longer
• Abdominal pain
• Nausea or vomiting

In addition, people with kidney disease should consult a healthcare provider before taking psyllium (Metamucil).

Potential for Interaction

Citrucel and Metamucil can interact with oral medications. These fibers can affect how other medications are absorbed in the intestines or delay their absorption. Talk to a healthcare provider before starting Citrucel or Metamucil if you take any medications.

To help prevent interactions, they will likely recommend taking Metamucil or Citrucel at least two hours before or after other medications.

While not a complete list, below are some examples of medications that can interact with Citrucel or Metamucil:

• Certain antidepressants, such as Elavil (amitriptyline) or Sinequan (doxepin)
• Anti-seizure medications, such as Tegretol (carbamazepine)
• Some bile acid sequestrants (medications used to lower cholesterol), such as Prevalite (cholestyramine) and Colestid (colestipol)
• Antiarrhythmic medications, such as Digox (digoxin)
• Mood stabilizing medications, such as Lithobid (lithium)
  

Preventing and Managing Constipation

In many cases, minor lifestyle changes can help to prevent or manage constipation. Studies show that diet changes are the best preventative against constipation, particularly in people experiencing frequent or recurring symptoms.

Often, constipation occurs due to insufficient fiber and fluid intake. Increasing dietary intake of fiber, as well as drinking plenty of water, helps prevent constipation and even relieves constipation in mild cases.

Exercise is another strategy for managing constipation, as increased physical activity is directly associated with improved digestive health and function. 

One study investigated the impact of exercise and diet changes over 12 weeks in people with frequent constipation.

The combined use of diet changes and exercise were associated with a significant improvement, doubling the number of bowel movements per week by the end of the study. Most of the participants also reported less straining and fewer incomplete bowel movements.

Summary

Citrucel and Metamucil are popular OTC medications used to relieve occasional constipation. They contain different active ingredients: Citrucel has methylcellulose fiber, while Metamucil contains psyllium fiber. Citrucel stays intact in the gut to add bulk to stool.

On the other hand, Metamucil dissolves in the gut, creating a gel-like coating on the intestinal wall that helps ease stool passage and soften stools.

Both options generally produce a bowel movement within 12 to 72 hours. Both products have drug interactions, so it’s best to separate other medications from Metamucil or Citrucel by at least two hours.

You can consult a healthcare provider or pharmacist for professional guidance in choosing a laxative.