Psyllium Supplement 101: Potential Benefits, Known Risks, and More

Lately, TikTok has popularized psyllium — a fiber supplement known primarily as the main ingredient in a popular over-the-counter laxative — as "budget Ozempic" for its purported weight loss effects.

While such claims are somewhat overstated, a growing body of research does show that fiber has myriad benefits beyond digestive health, yet Americans don’t get nearly enough in their diets, according to the current Dietary Guidelines for Americans, which flag fiber as a shortfall nutrient. Together, these facts have fueled demand for this all-important nutrient, particularly from supplements.

Psyllium (pronounced SIH-lee-uhm) is one such supplement. A type of fiber derived from a shrub-like herb, it is most commonly used as a laxative and is the main ingredient in the product Metamucil. Like other kinds of fiber, however, psyllium has many other health benefits, research suggests, and may play a role in improving heart health, helping manage weight and blood sugar level, and more. Here’s a closer look at what the science says about how psyllium impacts health, who should take it, and what side effects to look out for.

What Is Psyllium?

Psyllium, sometimes called psyllium husk, is a soluble fiber that comes from the seeds of Plantago ovata, a plant grown throughout the world but most commonly found in India, according to the American Botanical Council.

Psyllium is primarily used as a gentle, bulk-forming laxative. It’s also available as a dietary supplement and used by manufacturers to fortify foods, such as breakfast cereals and baked goods.

Similar to other types of fiber, which is essentially the nondigestible part of plants, psyllium husk can normalize bowel function and improve digestion.

“When mixed with liquid, psyllium forms a gel-like substance that can help promote bowel regularity,” says Kenneth Brown, MD, a gastroenterologist in Plano, Texas, and host of the Gut Check Project podcast. “This can be beneficial for people who suffer from constipation and diarrhea.”

Psyllium has also been prescribed to treat high cholesterol, according to MedlinePlus.

Psyllium is a dietary supplement that comes in a number of forms. Perhaps the most versatile is powder. “Psyllium can easily be added to things like water, smoothies, or other liquids to promote bowel regularity and overall digestive health,” says Samantha Schleiger, RDN, owner of Simply Nourished Functional Nutrition in Elkhorn, Wisconsin.

Forms of psyllium available for purchase include:

• Powder
• Capsules
• Gummies
• Thins, or wafers

Experts say no one form of psyllium is superior to others. “All forms are effective when paired with an 8-ounce (oz) cup of water, and taken as directed on the packaging,” notes Brooke Levine, RD, a dietitian at NYU Langone Health in New York City. Psyllium powder must be mixed with 8 oz of water or other liquid, and for any form of psyllium must be taken with at least 8 oz of liquid to work properly and to avoid side effects, according to MedlinePlus.

While psyllium is often associated with helping regulate bowel movements and improving digestion, the supplement has benefits that reach other parts of your body, as well.

Digestion and Gut Health

Psyllium acts as a stool softener and is most frequently used as a laxative. Chronic constipation is a common gastrointestinal condition, affecting up to 12 percent of adults, according to a research review published in July 2022 in The American Journal of Clinical Nutrition. Fiber supplementation, particularly psyllium, is effective at treating constipation when used for at least four weeks, the authors of the review concluded.

But constipation isn’t the only GI disorder psyllium can help with. “Psyllium can also reduce diarrhea by absorbing excess water in the gut and forming a more solid stool,” Dr. Brown says.

Psyllium can also help to relieve symptoms of hemorrhoids, such as itching, discomfort, and rectal bleeding, by promoting regular bowel movements and preventing constipation, Brown notes. One past study of 102 adults with severe hemorrhoids found that supplementing with psyllium husk stopped the progression of the condition and prevented surgery from being necessary for the majority of patients.

Excessive gas is one of the prominent symptoms of irritable bowel syndrome (IBS). The results of one small study of 19 people with IBS suggested that psyllium husk may help alleviate these, as well as other symptoms like abdominal pain and bloating. The findings were published in Gut in 2022, but additional research is needed.

When it comes to inflammatory bowel disorders like Crohn disease and ulcerative colitis, the evidence is mixed due to the complex nature of IBD. “Some studies have suggested that psyllium may help to reduce inflammation and improve symptoms in people with IBD, while others have found no significant benefits and can cause more discomfort,” Brown notes. “More research is needed to fully understand the effects of psyllium on IBD.” If you have Crohn or ulcerative colitis and are curious about psyllium supplementation, talk to your doctor, who can help you decide how much fiber is right for you.

A new area of research is psyllium’s effect on the gut microbiome, the community of bacteria, fungi, viruses, and other microorganisms that are present in the gastrointestinal tract. A small study, published online in the International Journal of Molecular Science in January 2019, suggests that psyllium can have a positive impact on the gut microbiome. “Psyllium is a prebiotic fiber, which helps to feed the beneficial bacteria in the gut,” Schleiger says. “Optimal amounts of beneficial bacteria in the gut are essential not only for regular bowel habits but also for proper digestion and absorption of nutrients.”

Heart Health

Research, including a review of 28 clinical trials published in November 2018 in The American Journal of Clinical Nutrition, has shown that psyllium can lower total, as well as LDL or “bad” cholesterol. “This is likely due to its ability to absorb water and form a gel-like substance in the gut, which can trap cholesterol and other waste products and carry them out of the body,” Brown explains.

Adding fiber to your diet, particularly psyllium husk, may also help lower blood pressure, according to a systematic review and meta-analysis published in the Korean Journal of Internal Medicine in January 2020. These benefits of psyllium means it may be a useful tool in warding off heart disease.

Diabetes

Psyllium husk may also help people better manage type 2 diabetes. One past study looked at 40 patients with type 2 diabetes, 20 of whom were put on 10.5 grams of psyllium every day, while the other 20 continued their normal diet. After eight weeks, those on the high-fiber diet experienced a significant reduction in blood sugar levels compared with those on their regular diet. “Psyllium slows the digestion and absorption of carbohydrates, which can help to prevent spikes in blood sugar levels,” Brown says. The supplement may also be a useful tool in preventing diabetes in those at risk, per Mount Sinai.

In addition to aiding digestion and improving heart health, psyllium may help you lose weight. It’s important to note that studies on this topic have yielded mixed results, and a research review of 22 randomized controlled trials published in 2020 concluded that psyllium supplementation did not have a significant effect on the reduction of body weight or BMI (body mass index). Still, experts say soluble fibers like psyllium may have an indirect effect on weight loss by curbing your appetite.

“Because psyllium absorbs liquid in the gut, it can help promote the feeling of fullness and lessen your likelihood of overindulging at meal times,” Schleiger says. If you’re interested in trying psyllium for weight loss, talk to your doctor to see if this is a smart option for you.

While psyllium comes with a number of health benefits and is considered to be generally safe for most people, it’s not for everyone. People with certain health conditions should avoid psyllium and there are several drug interactions and side effects to be aware of.

Risks

Psyllium is not recommended for people with a history of bowel obstruction, per Mount Sinai. “Psyllium can expand and cause blockages in the esophagus or intestine, especially in people with a history of these conditions,” Brown says. It can also expand in the throat so is not advised for people who have difficulty swallowing, he says.

Mount Sinai also notes that people with kidney disease should check with their doctor before using psyllium. If they do take psyllium, it is best to space it out from prescription drugs by taking it either one hour before or two hours after their other medications.

Children should get fiber from their diet, so it is not recommended they supplement with psyllium unless advised by a pediatrician, Schleiger notes.

Psyllium may also have interactions or reduce or delay absorption of a number of medications and supplements, including:

• Tricyclic antidepressants
• Seizure medications like carbamazepine
• Lithium
• Digoxin (used to treat heart arrhythmias and heart failure)
• Diabetes medication like Metformin

If you’re being treated with any of these medications, do not take psyllium until you have consulted with your doctor.

Side Effects

Psyllium may lead to a number of side effects, according to Cleveland Clinic, including:

• Abdominal pain and cramping
• Gas
• Bloating
• Loose stools of diarrhea
• Frequent bowel movements
• Nausea
• Vomiting

These symptoms are more common when first using psyllium or when taking more than the recommended dose.

Psyllium is considered to be generally safe for most people. Individuals struggling with constipation or diarrhea may want to consider supplementation with psyllium to help regulate their bowel movements.

Psyllium may also be a smart option for people looking to improve their cholesterol, blood pressure, and glucose levels, though it’s important to speak to your physician before doing so, especially if you are already on medication to treat these or other conditions.

When purchasing psyllium, there are a few things you should keep in mind. Similarly, you’ll also want to make sure you store your supplements in a safe way.

Selection

When selecting a type of psyllium to purchase, Brown recommends opting for pure psyllium husk.

“Other fibers will sometimes add sugar, sugar substitutes, binders, or artificial flavors, all to make it more palatable,” he says. “Most of this is for marketing purposes.”

And experts say it’s best to avoid products that stack psyllium with other supplements, especially when you’re first introducing it to your diet. “Sometimes if there are additional ingredients, and you don't tolerate it at first, it can be difficult to determine what exactly you're not tolerating in the formula,” Schleiger says.

Storage

It’s also important to store psyllium correctly to keep it fresh and prevent contamination. Schleiger recommends storing psyllium in a cool, dry place inside a dry, sealed container.“Store away from light, moisture, or heat to prevent the chances of the psyllium going bad or mold growth,” she says.

When it comes to how much psyllium you should take, the appropriate amount can vary from person to person. “Dosage should be individualized and adjusted based on a person's overall gut health and tolerance,” Schleiger says. “For example, some people may experience worsened symptoms with the implementation of psyllium which may indicate a suboptimal gut microbiome or gut dysfunction, so guidance by a skilled practitioner is key.”

In general, studies have shown that taking about 8 to 10 grams of psyllium daily may help with blood sugar balance and overall gut support, she notes. But if you have any questions or concerns, talk to your doctor. A good rule of thumb is to introduce psyllium gradually. “When adding fiber into your diet, start with a small dosage and increase dosage as tolerated as directed on the packaging,” Levine advises.

Psyllium is a supplemental fiber that can help relieve constipation and regulate bowel movements. Research suggests it may have additional health benefits, including lowering cholesterol, blood pressure, and blood sugar levels, which can help reduce the risk of heart disease and diabetes.

People with a history of bowel obstruction and swallowing disorders should not take psyllium. Talk to your doctor before introducing any supplement into your diet, especially if you are taking other medications, as there may be drug interactions you need to be aware of.