Jennifer Lefton, MS, RD/N-AP, CNSC, FAND is a Registered Dietitian/Nutritionist and writer with over 20 year of experience in clinical nutrition.

Betthany (Beth) Thomas, PharmD, is a clinical pharmacist and founder of BMT Coaching

Psyllium is a form of soluble fiber sourced from the husks of the psyllium (Plantago ovata ) seed. This plant is native to Asia and grows mostly in India, but it can be found worldwide. In fact, it grows wild in the southwest United States.

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.

Dietary supplements are not regulated in the United States, meaning the FDA does not approve them for safety and effectiveness before products are marketed. When possible, choose a supplement that has been tested by a trusted third party, such as USP, ConsumerLabs, or NSF. However, even if supplements are third-party tested, that doesn't mean that they are necessarily safe for all of effective in general. It is important to talk to your healthcare provider about any supplements you plan to take and to check in about any potential interactions with other supplements or medications.

Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietician, pharmacist, or doctor. No supplement is intended to treat, cure, or prevent a disease.

As a source of soluble fiber, psyllium slows digestion, allowing the body to absorb nutrients from your food as it passes through the stomach and intestines.

There are four types of soluble fiber you might hear about:

Psyllium is much like other sources of soluble fiber found in foods such as:

Like 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:

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 and quality of life. However, one placebo-controlled study of psyllium showed no significant benefit compared with placebo. In other trials, psyllium was less effective than other nonpharmacological agents for treating constipation, such as prunes and lactulose. A recent systematic review concluded that moderate evidence supports psyllium's use for treating constipation, although more high-quality research is needed.

Adding soluble fiber to your diet may help to lower your cholesterol. In fact, the Food and Drug Administration (FDA) allows health claims about the relationship between soluble fiber and the reduced risk of heart disease on the labels of psyllium-containing products. However, it is important. to understand that these are not meant to be used as the only means to reduce heart-related risks.

Soluble fiber interferes with the absorption of bile acids in the intestines, which forces the bile acids to be excreted out in the stool. To make up for the lost bile acid, the liver has to use cholesterol. In this process, levels of low-density lipoprotein (LDL) "bad" cholesterol are reduced. That's good news for your overall cholesterol numbers.

Several studies have looked at psyllium's cholesterol-lowering effects, including the following:

According to the National Lipid Association, consuming 5 to 10 grams of soluble fiber daily can lower your total cholesterol and LDL cholesterol by five to 11 points.

If you're taking statin drugs to manage your cholesterol, adding psyllium fiber to your diet may also help improve cholesterol-lowering effects.

Irritable bowel syndrome (IBS) is a group of symptoms that affect your digestive system. The exact cause of IBS is unknown. In people with IBS, soluble fiber is believed to improve abdominal pain, abdominal bloating and distension, and flatulence compared with insoluble fiber.

A meta-analysis, published in 2014, evaluated dietary fiber supplementation in 14 randomized controlled trials that included 906 people with IBS. The results showed that fiber supplements (especially psyllium) reduced symptoms associated with IBS.

Follow your healthcare provider's guidance for managing IBS symptoms.

About one in 10 Americans have diabetes, a chronic condition that affects blood sugar levels. Some research suggests that soluble fiber such as psyllium may help people with type 2 diabetes manage their blood sugar levels.

Specifically, researchers have found that taking psyllium before meals can significantly improve your fasting blood glucose (sugar) when you have type 2 diabetes. In another study, adding 10 g of psyllium daily helped improve blood glucose levels in people with type 2 diabetes.

Soluble fiber is also said to help you feel full after eating (satiety). This can help prevent you from overeating throughout the day. Psyllium supplementation can also help you to feel less hungry between meals.

Despite this, research has not found psyllium to help with weight loss. A meta-analysis published in 2020 concluded that psyllium supplementation had no favorable effect on body weight, body mass index (BMI), and waist circumference.

Psyllium is a soluble fiber source that absorbs water and forms a gel in the digestive tract. Consuming more soluble fiber in the form of psyllium helps slow down the process of digesting food, possibly giving your body a chance to get more nutrients from the food you eat.

Psyllium supplementation may help with constipation, improve cholesterol levels, manage symptoms associated with IBS, and help with blood sugar management in people with diabetes. However, it does not appear to help with weight loss.

Several common side effects can occur when taking fiber supplements, including gas and bloating.

It's important to drink enough fluids while taking psyllium. Not drinking enough water may worsen constipation or cramping that fiber is meant to relieve. 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.

Some people can have severe or allergic reactions to psyllium. If you have any of the following symptoms after taking the supplement, contact your healthcare provider:

Psyllium supplements may not be right for everyone, including:

If you have difficulty swallowing or a narrowing anywhere in your digestive tract, talk to your healthcare provider before you start using soluble fiber supplements.

Psyllium may also interact with certain types of medication. Tell your healthcare provider about the medications you take, both prescription and over-the-counter, before starting a new supplement.

Psyllium comes in many forms—as a powder, granules, capsule, liquid, and wafer. Only take the recommended dosage, and be sure you drink at least the water or liquid required for that dosage. Without adequate fluids, you may become constipated or develop a bowel obstruction.

If you are not used to taking psyllium, it's best to begin with a low dose, such as a 1/2 teaspoon of powder in an 8-ounce glass of water once a day. Gradually, you can increase the dose as needed.

The National Academies of Sciences, Engineering and Medicine recommends a fiber intake of about 25 g per day for females (sex assigned at birth) and 38 g per day for males for adults aged 21 to 50. Older adults tend to consume fewer calories, so the recommendation for females and males over 50 is 21 grams and 30 grams per day, respectively.

While allergic reactions are not common, some people are highly sensitive to psyllium. Contact your healthcare provider if you show signs of an allergy such as hives, difficult breathing, facial swelling, or swelling of the lips, tongue, or throat.

Taking too much psyllium will most likely lead to experiencing side effects of gas, bloating, cramping, or abdominal pain. This is especially true if you don't consume enough water with psyllium.

In rare cases, it may cause intestinal blockage. Be sure to follow the directions for taking psyllium and discuss it with your healthcare provider so that you have a plan for how much to take and for how long.

Psyllium can interact with several medications. Psyllium supplementation may affect the absorption of the following:

Follow directions on packaging for proper storage. Generally, all medications and supplements should be stored out of reach of children.

For most healthy people, psyllium is safe to take and can offer a variety of benefits. Only people with certain conditions are advised to not take psyllium, such as those with digestive conditions, kidney disease, or those who have trouble swallowing. Children should also not be given psyllium without a healthcare provider's guidance.

It depends on why you're taking it. If you're treating constipation, you should use psyllium for no longer than one week. As a fiber supplement, you may be able to take it every day, but you should only do so with your healthcare provider's guidance.

Metamucil is one brand name of fiber supplements that contain psyllium. Others include Fiberall, Maalox Daily Fiber Therapy, and Hydrocil. All are available over the counter.

Psyllium is found in foods that provide fiber. It can also be found in supplement form.

Before incorporating a fiber supplement like psyllium, consider whether you can increase your fiber consumption by changing your diet.

Food sources of soluble fiber include:

Food sources of insoluble fiber include:

Psyllium supplements come in many forms. It is often found in powder or wafer form but can also be in capsules, granules, or liquid concentrate.

As mentioned before, always look for supplements that have been third-party tested. Consult with your healthcare provider before adding supplements into your diet.

Psyllium is a source of soluble fiber. It is found naturally in the foods we eat and is also available as a supplement.

Psyllium supplementation may have health benefits, including helping with constipation, improving cholesterol levels, alleviating IBS symptoms, and helping to improve blood sugar control in people with diabetes. It's 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. For every 3 to 5 grams of psyllium husk, drink 8 ounces of fluid. Start with a small amount of psyllium and slowly increase the dosage so your system can get used to the change and adapt. Talk to your healthcare provider about supplementation and medications to ensure you are taking the appropriate amount.

Cathy Wong is a nutritionist and wellness expert. Her work is regularly featured in media such as First For Women, Woman's World, and Natural Health.

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Bruma Jose M. Satiety effects of psyllium in healthy volunteers. Appetite. 2016;105:27-36. doi:10.1016/j.appet.2016.04.041

MedlinePlus. Soluble and insoluble fiber.

Rao S, Brenner D. Efficacy and safety of over-the-counter therapies for chronic constipation: An updated systematic review. The American Journal of Gastroenterology. 2021. doi:10.14309/ajg.0000000000001222

Erdogan A, Rao SSC, Thiruvaiyaru D, et al. Randomised clinical trial: mixed soluble/insoluble fibre vs psyllium for chronic constipation. Ailment Pharmacol Ther. 2016;44(1):35-44. doi:10.1111/apt.13647

Cheng J, Tennila J, Stenman L. Influence of lactitol and psyllium on bowel function in constipated Indian volunteers: A randomized controlled trial. Nutrients. 2019, 11(5), 1130. doi:10.3390/nu11051130

Attaluri A, Donahoe R, Valestin J, et al. Randomised clinical trial: dried plums (prunes) vs. psyllium for constipation. Ailment Pharmacol Ther. 2011; 33(7):822-8. doi:10.1111/j.1365-2036.2011.04594.x

Food and Drug Administration. CFR - Code of Federal Regulations Title 21.

Jovanovski E, Yashpal S, Komishon A, et al. Effect of psyllium (Plantago ovata) fiber on LDL cholesterol and alternative lipid targets, non-HDL cholesterol and apolipoprotein B: a systematic review and meta-analysis of randomized controlled trials. The American Journal of Clinical Nutrition. 2018;108(5):922-932. doi: 10.1093/ajcn/nqy115

Schoeneck M, Iggman D. The effects of foods on LDL cholesterol levels: A systematic review of the accumulated evidence from systematic reviews and meta-analyses of randomized controlled trials. Nutrition, Metabolism, and Cardiovascular Disease. 2021; 6;31(5):1325-1338. doi:10.1016/j.numecd.2020.12.032

Anderson JW, Allgood LD, Lawrence A, et al. Cholesterol-lowering effects of psyllium intake adjunctive to diet therapy in men and women with hypercholesterolemia: meta-analysis of 8 controlled trials.The American Journal of Clinical Nutrition. 2000;71(2):472-479.doi:10.1093/ajcn/71.2.472

National Lipid Association. Adding soluble fiber to lower your cholesterol.

Brum J, Ramsey D, McRorie J, et al. Meta-analysis of usefulness of psyllium fiber as adjuvant antilipid therapy to enhance cholesterol lowering efficacy of statins. The American Journal of Cardiology. 2018; 122(7):1169-1174. doi:10.1016/j.amjcard.2018.06.040

Moayyedi P, Quigley EM, Lacy BE, et al. The effect of fiber supplementation on irritable bowel syndrome: a systematic review and meta-analysis. Am J Gastroenterol. 2014;109(9):1367-74. doi:10.1038/ajg.2014.195

Centers for Disease Control and Prevention. Type 2 Diabetes.

Gibb RD, McRorie JW Jr, Russell DA, et al. Psyllium fiber improves glycemic control proportional to loss of glycemic control: a meta-analysis of data in euglycemic subjects, patients at risk of type 2 diabetes mellitus, and patients being treated for type 2 diabetes mellitus. Am J Clin Nutr. 2015 Dec;102(6):1604-14. doi:10.3945/ajcn.115.106989

Abutair AS, Naser IA, Hamed AT. Soluble fibers from psyllium improve glycemic response and body weight among diabetes type 2 patients (randomized control trial). Nutr J. 2016;15(1):86. doi:10.1186/s12937-016-0207-4

Darooghegi Mofrad M, Mozaffari H, Mousavi SM. The effects of psyllium supplementation on body weight, body mass index and waist circumference in adults: A systematic review and dose-response meta-analysis of randomized controlled trials. Crit Rev Food Sci Nutr. 2019;60(5):859-872. doi:10.1080/10408398.2018.1553140

Mount Sinai Hospital. Psyllium information.

Food Information Council Foundation. Fiber fact sheet.

University of Michigan Health. Psyllium.

Yui Kau Fong S, Gao Q, Zuo Z. Interaction of carbamazepine with herbs, dietary supplements, and food: A systematic review. Evid Based Complement Alternat Med. 2013; 2013: 898261. doi:10.1155/2013/898261

Reissel P, Manninen V. Effect of administration of activated charcoal and fibre on absorption, excretion and steady state blood levels of digoxin and digitoxin. Evidence for intenstinal secretion of the glycosides. Acta Medica Scandinavica. 1982. doi:10.1111/j.0954-6820.1982.tb08527.x

Rossander L. Effect of dietary fiber on iron absorption in man. Scandinavian Journal of Gastroenterology. 2009. doi:10.1111/j.0954-6820.1982.tb08527.x

Gardiner P, Phillips R, Shaugnessy AF. Herbal and dietary supplement-drug interactions in patients with chronic illness. Am Fam Physician. 2008;77(1):73-78.

Díez R, García JJ, Diez MJ, et al. Influence of Plantago ovata husk (dietary fiber) on the bioavailability and other pharmacokinetic parameters of metformin in diabetic rabbits. BMC Complement Altern Med. 2017; 17:298. doi:10.1186/s12906-017-1809-x

Merrick C, Madden CA, Capurso NA. A case of blunted orally disintegrating olanzapine effect due to coadministered psyllium. The Journal of Clinical Psychiatry. 2021;82(2):20cr13633. doi:10.4088/JCP.20cr13633

El-Salhy M, Ystad SO, Mazzawi T, Gundersen D. Dietary fiber in irritable bowel syndrome (Review). Int J Mol Med. 2017 Sep; 40(3): 607–613. doi:10.3892/ijmm.2017.3072

University of California San Francisco. Increasing fiber intake.

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