Overview

Black psyllium comes from the seed husks of the Plantago arenaria plant. It contains high amounts of soluble dietary fiber.

Black psyllium adds bulk to the stool which might help with constipation, diarrhea, and irritable bowel syndrome (IBS). It also controls how quickly sugars are absorbed from the gut, which might help control blood sugar levels in people with diabetes.

People commonly use black psyllium for treating and preventing constipation. It is also used for diarrhea, obesity, diabetes, high blood pressure, and many other conditions, but there is no good scientific evidence to support most of these uses.

Don't confuse black psyllium with blond psyllium. These are not the same.



Uses & Effectiveness

Effective for

  • Constipation. Consuming soluble dietary fiber by mouth, including black psyllium, is effective for short-term constipation. It's found in over-the-counter (OTC) products for this use.

Likely Effective for

  • Heart disease. Consuming foods high in soluble fiber, including black psyllium, as part of a low-fat, low-cholesterol diet, might help prevent heart disease. At least 7 grams of psyllium husk must be consumed daily.

There is interest in using black psyllium for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful.

Side Effects

When taken by mouth: Black psyllium is likely safe when consumed with plenty of water. Drink at least 8 ounces of fluids for every 3-5 grams of husk or 7 grams of seed. Mild side effects include bloating and gas. In some people, black psyllium can cause allergic reactions.

Black psyllium is likely unsafe when consumed without enough water. It might cause choking or block the gastrointestinal (GI) tract.

Special Precautions and Warnings

When taken by mouth: Black psyllium is likely safe when consumed with plenty of water. Drink at least 8 ounces of fluids for every 3-5 grams of husk or 7 grams of seed. Mild side effects include bloating and gas. In some people, black psyllium can cause allergic reactions.

Black psyllium is likely unsafe when consumed without enough water. It might cause choking or block the gastrointestinal (GI) tract.

Pregnancy and breast-feeding: Taking black psyllium during pregnancy or breast-feeding seems to be safe, as long as enough fluids are taken with each dose.

Gastrointestinal (GI) disorders: Don't use black psyllium if you tend to develop hard stools in the rectum due to GI tract narrowing, or have a condition that can lead to obstruction, such as spastic bowel.

Phenylketonuria: Some black psyllium products might be sweetened with aspartame (NutraSweet). If you have phenylketonuria, avoid these products.

Swallowing disorders: Do not use black psyllium if you have problems swallowing. Black psyllium might increase your risk of choking.

Interactions

    Moderate Interaction

    Be cautious with this combination

  • Carbamazepine (Tegretol) interacts with Black Psyllium

    Black psyllium contains large amounts of fiber. Fiber can decrease how much carbamazepine the body absorbs. This might decrease the effects of carbamazepine.

  • Digoxin (Lanoxin) interacts with Black Psyllium

    Black psyllium is high in fiber. Fiber can decrease how much digoxin the body absorbs. This might decrease the effects of digoxin.

  • Ethinyl estradiol interacts with Black Psyllium

    Ethinyl estradiol is a form of estrogen. Psyllium can decrease how much ethinyl estradiol the body absorbs. But it is unlikely that this will reduce the effects of ethinyl estradiol.

  • Lithium interacts with Black Psyllium

    Black psyllium contains large amounts of fiber. Fiber can decrease how much lithium the body absorbs. This might decrease the effects of lithium. To avoid this interaction, take black psyllium at least 1 hour after lithium.

  • Olanzapine (Zyprexa) interacts with Black Psyllium

    Black psyllium contains large amounts of fiber. Fiber can decrease how much olanzapine the body absorbs. This might decrease the effects of olanzapine.

  • Metformin (Glucophage) interacts with Black Psyllium

    Black psyllium contains large amounts of fiber. The fiber in psyllium might increase how much metformin the body absorbs. This might increase the effects of metformin. To avoid this interaction, take black psyllium 30-60 minutes after medications you take by mouth.

    Minor Interaction

    Be watchful with this combination

  • Medications taken by mouth (Oral drugs) interacts with Black Psyllium

    Black psyllium contains large amounts of fiber. Fiber can decrease, increase, or have no effect on how much medicine the body absorbs. Taking black psyllium along with medicine you take by mouth can impact the effects of your medicine. To prevent this interaction, take black psyllium 30-60 minutes after medications you take by mouth.

Dosing

Black psyllium has most often been used by adults in doses of 10-30 grams by mouth, in 1-3 divided doses daily, for up to 6 months. Always drink at least 8 ounces of fluids for every 3-5 grams of husk or 7 grams of seed. Speak with a healthcare provider to find out what type of product and dose might be best for a specific condition.
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CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

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