Some people may need a fiber supplement such as psyllium to help with various health issues. Psyllium is sold under a wide variety of brand names but is probably best known as Metamucil.
This article discusses the potential benefits of psyllium, how to take it, and how to potentially get the same benefits from food in your diet.
Benefits of Psyllium
As a source of soluble fiber, psyllium slows digestion. This allows your body to absorb more nutrients from your food as it passes through the stomach and intestines.
Active ingredient(s): PsylliumAlternate Name(s): Psyllium husk, ispaghula huskSuggested Dose: 10 grams dailySafety Considerations: Discuss with a healthcare provider
Psyllium is much like other sources of soluble fiber found in foods such as:
Oat branBarleyNutsSeedsBeansLentilsPeasSome fruits and vegetables
As do the above foods, psyllium attracts water as it goes through the digestive system and turns into a gel-like substance that helps digestion.
Soluble fiber is said to help with a wide range of health issues, including:
Constipation High cholesterol (hyperlipidemia) Irritable bowel syndrome (IBS) Diabetes
Constipation
Increasing your intake of soluble fiber helps you have regular bowel movements.
As psyllium makes its way down your digestive tract, it absorbs water in the intestines, swells, and contributes to the formation of a gel-like stool that’s soft and easy to pass.
Incorporating soluble fiber, like psyllium, into your diet has been shown to improve constipation, which in turn can improve your quality of life. However, one placebo-controlled study of psyllium showed no significant benefit.
In other trials, psyllium was less effective than other nonpharmacologic agents for treating constipation, such as prunes.
A 2021 systematic review (summary of medical literature on a specific topic) concluded there’s moderate evidence to support using psyllium for constipation. More high-quality research is needed, though.
High Cholesterol
Adding soluble fiber to your diet may help lower your cholesterol, which reduces your risk of heart disease. The FDA even allows manufacturers to make this claim on their labels.
Even so, fiber should not be the only thing you use to lower your risk of heart disease.
Soluble fiber interferes with the absorption of bile acids (used for digestion) in the intestines, which forces them to be excreted in the stool. Your liver usually uses bile acids, and when there aren’t enough, it uses cholesterol, instead.
This process lowers levels of low-density lipoprotein (LDL) cholesterol, considered “bad” cholesterol. That generally improves your overall cholesterol numbers.
Several studies have looked at psyllium’s cholesterol-lowering effects, including:
A 2018 meta-analysis (statistical analysis of multiple scientific studies) found that 10 grams of psyllium daily significantly lowered LDL cholesterol levels. A 2021 systematic review found foods high in soluble fibers, such as psyllium, resulted in moderate LDL cholesterol reduction.
According to the National Lipid Association, eating 5–10 grams of soluble fiber daily can lower your total cholesterol and LDL cholesterol by between five and 11 points.
If you’re taking statin drugs to manage your cholesterol, adding psyllium fiber to your diet may help improve its cholesterol-lowering effects.
Irritable Bowel Syndrome
Irritable bowel syndrome (IBS) causes an array of digestive symptoms. The exact cause of IBS is unknown.
In people with this condition, soluble fiber is believed to be better than insoluble fiber at improving:
Abdominal painAbdominal bloating and distensionFlatulence (gas)
A 2014 meta-analysis evaluated dietary fiber supplementation in 14 randomized controlled trials (studies in which, by chance, half the group is given the treatment being investigated and half is not) that included 906 people with IBS. The results showed fiber supplements (especially psyllium) reduced IBS symptoms.
Follow your healthcare provider’s guidance for managing IBS symptoms.
Diabetes
About 1 in 10 Americans has diabetes, a chronic condition that affects blood sugar levels. Some research suggests soluble fiber such as psyllium may help people with type 2 diabetes manage blood sugar levels.
Specifically, researchers have found taking psyllium before meals can significantly improve your fasting blood glucose (sugar) when you have this condition.
In another study, adding 10 grams of psyllium daily helped improve blood glucose levels in people with type 2 diabetes.
Satiety
Soluble fiber is believed to help you feel full after eating (satiety) and feel less hungry between meals. This may keep you from overeating.
Despite these effects, research has not found psyllium to help with weight loss. A 2020 meta-analysis concluded psyllium supplementation had no favorable effect on body weight, body mass index (BMI), or waist circumference.
What Are the Side Effects of Psyllium?
Several common side effects can occur when taking fiber supplements, including:
Gas Bloating
Constipation and Cramping
It’s important to drink enough fluids while taking psyllium. Not drinking enough water may worsen constipation or cramping fiber is meant to relieve. It can also lead to a bowel obstruction, which causes severe pain and cramping.
Drink at least one 8-ounce glass of water with the supplement and at least six to eight glasses throughout the day.
Being physically active also helps reduce the risk of constipation when taking psyllium.
Allergic Reactions
While allergic reactions are not common, some people are highly sensitive to psyllium. Contact your healthcare provider if you have:
Hives or rashItchingBreathing problems, such as wheezingStomach painTrouble swallowingNausea and vomitingSwelling of the face, lips, tongue, or throat
A psyllium allergy could lead to anaphylaxis, which is a life-threatening emergency. Watch for symptoms that affect two or more systems in your body, such as hives and wheezing.
Always get immediate medical care for a serious allergic reaction.
Precautions
Psyllium supplements may not be right for everyone. They shouldn’t be taken by:
Children, unless it’s recommended by their healthcare provider People with bowel spasms or a history of bowel obstruction People with a history of colon or rectal cancer People who are allergic to psyllium People with phenylketonuria (PKU), an inherited metabolic disorder
If you have difficulty swallowing or narrowing anywhere in your digestive tract, talk to your healthcare provider before using soluble fiber supplements.
Interactions
Psyllium can interact with several medications. It may affect the absorption of:
Tegretol (carbamazepine) Lanoxin (digoxin) (Take one hour before or four hours after psyllium. ) Iron Lithium Glumetza (metformin) (Take psyllium at least 30–60 minutes after taking metformin. ) Zyprexa (olanzapine)
Tell your healthcare provider and pharmacist about all the medications you take, both prescription and over-the-counter drugs, herbs, and supplements, before starting a new supplement.
Dosage: How Much Psyllium Should I Take?
Only take the recommended dosage of psyllium, and be sure you drink at least the water or liquid required for that dosage.
If you aren’t used to taking psyllium, it’s best to begin with a low dose, such as:
1/2 teaspoon of powderIn an 8-ounce glass of waterOnce a day
Then you can gradually increase the dose as needed.
For people between the ages of 21 and 50, the National Academies of Sciences, Engineering and Medicine recommends a fiber intake of about:
25 grams per day for those assigned female at birth (AFAB)38 grams per day for those assigned males at birth (AMAB)
Older adults tend to consume fewer calories, so the recommendation for people over 50 is:
21 grams per day for those AFAB30 grams per day for those AMAB
What Happens If I Take Too Much Psyllium?
Taking too much psyllium will most likely lead to side effects of:
GasBloatingCrampingAbdominal pain
This is especially true if you don’t drink enough water with psyllium.
In rare cases, taking too much psyllium may cause an intestinal blockage. Be sure to follow the directions and discuss it with your healthcare provider so you know how much to take and for how long.
How to Store Psyllium
Follow directions on packaging for proper storage. Generally, all medications and supplements should be stored out of reach of children.
Sources of Psyllium & What to Look For
Psyllium is found in foods that provide fiber. It can also be found in supplement form.
Food Sources of Psyllium
Before taking a fiber supplement like psyllium, consider whether you can increase your fiber consumption by changing your diet.
Food sources of soluble fiber include:
OatsBarleyNutsSeedsLegumes (such as beans, lentils, and peas)VegetablesFruits like apples, oranges, and grapefruit
Food sources of insoluble fiber include:
Fruits with edible peels or seedsVegetablesWhole-grain products (such as whole wheat bread, pasta, and crackers)Bulgur wheatStone ground cornmealCerealsBranRolled oatsBuckwheatBrown rice
Psyllium Supplements
Psyllium supplements come in many forms:
PowderGranulesCapsuleLiquidWafers
Always look for supplements that have been third-party tested.
Summary
Psyllium is a source of soluble fiber. It’s naturally in many foods and available as a supplement. Psyllium supplements may help improve constipation, cholesterol levels, IBS symptoms, and blood sugar control in diabetes.
Psyllium is best used in combination with other treatments and preventive strategies, including diet, lifestyle changes, and medication.
If you don’t get enough fiber in your diet, psyllium supplementation may be beneficial. Be sure to follow the instructions for dosage and how much water to drink with them.
Talk to your healthcare provider about any supplements you’re interested in before taking them.
