Dietary fiber is crucial for optimal digestive health, but its benefits extend beyond the gut. Adequate fiber intake can reduce the risk of heart disease, lower cholesterol, keep blood sugar levels stable, and support digestive regularity. For optimal fiber intake, we recommend eating various fruits, vegetables, nuts, whole grains, and legumes. However, if you find it challenging to get enough fiber or are looking for help managing digestive conditions, including diarrhea, constipation, and Irritable Bowel Syndrome (IBS), a fiber supplement may be useful.
To determine the best fiber supplements, we analyzed the latest research and spoke with dietitians specializing in gastrointestinal (GI) conditions, diabetes, and children’s health. Here are the best fiber supplements for digestion and health.
Editor’s Note
Our team of registered dietitians reviews and evaluates every supplement we recommend according to our dietary supplement methodology.
If you have ongoing or worsening gastrointestinal symptoms such as severe constipation, diarrhea, or abdominal pain, it’s best to work with a healthcare provider to clarify the nature of the condition before supplementing fiber. Additionally, you should avoid fiber supplements if you have difficulty swallowing, esophageal stricture, impacted stool, bowel obstruction, or active intestinal inflammation.
Always speak with a healthcare professional before adding a supplement to your routine to ensure that it is appropriate for your individual needs and to find out what dosage to take.
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Key Specs
Fiber Source: Psyllium husk | Serving Size: 1 rounded teaspoon | Servings per Container: 136 | Fiber per Serving: 4.5 grams | Other Ingredients: None
Who It’s For
Best for those who want a single-ingredient, research-backed fiber supplement.
Why We Love It
Psyllium supplements, the most research-backed fiber supplements, are made from psyllium seed husk, a non-fermentable, soluble fiber with viscous, gel-forming properties. Psyllium can reduce LDL cholesterol levels, control blood sugar, slow digestion, and increase satiety. It may also help with constipation, diarrhea, and symptoms of IBS.
Yerba Prima’s Psyllium Husks Powder is a convenient supplement that can be easily added to food, such as baked goods, yogurt, or smoothies. The tasteless supplement blends well without changing the flavor of the food. While this specific product is not independently verified, it’s a top choice amongst dietitians, and it’s worth noting that it contained the lowest amount of lead of all fiber supplements tested by Consumer Lab.
Potential Flaws
- When mixed with liquid, psyllium husks will thicken quickly. Therefore, the manufacturer recommends consuming it immediately after mixing.
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Key Specs
Fiber Source: Flaxseed | Serving Size: 2 tablespoons | Fiber per Serving: 3 grams | Other Ingredients: None
Who It’s For
Best for those experiencing symptoms of constipation who want a fiber supplement that’s easy to add to many foods.
Why We Love It
If you are experiencing constipation, you may benefit from a fiber supplement containing soluble and insoluble fiber. Insoluble fiber stimulates the colon to produce water, adding soft bulk to stool and making it easier to pass bowel movements. Research shows that ground flaxseed may help alleviate symptoms of constipation. Flaxseeds are also a source of heart-healthy omega-3 fats, promote blood sugar balance, and have cancer-protective properties, making them an all-around beneficial food.
Viva Naturals’ Organic Ground Flaxseed contains 3 grams of fiber per 2 tablespoons and no other ingredients. Ground flaxseed is very easy to incorporate into your daily eating plan and is helpful if you are following an anti-inflammatory diet. Its slightly nutty flavor makes it a tasty, fiber-rich addition to baked goods, yogurt, salads, oatmeal, or smoothies.
Potential Flaws
- Because it contains both soluble and insoluble fiber, it may cause bloating and gas.
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Key Specs
Fiber Source: Methylcellulose | Serving Size: 2 caplets | Fiber per Serving: 2 grams | Other Ingredients: Crospovidone, dibasic calcium phosphate, FD&C yellow No. 6 aluminum lake, magnesium stearate, maltodextrin, povidone, sodium lauryl sulfate
Who It’s For
Best for those experiencing diarrhea and constipation who want a fiber supplement that supports bowel movement regularity.
Why We Love It
Soluble fiber absorbs water and forms into a gel, slowing digestion and adding bulk to stool. A non-fermentable, soluble fiber supplement may, therefore, be beneficial if you are experiencing diarrhea. Citrucel’s Fiber Therapy Caplets contain methylcellulose, which absorbs water and can help you form cohesive and solid stools. This supplement supports overall regularity, and it may be used to treat constipation as well.
Some fiber supplements require mixing in water, which can get messy. We like that this supplement comes in caplet form, making it easy to take. For adults over age 12, the recommended dose is to start with two caplets and increase as needed without exceeding six caplets per day. This product is also non-fermentable, meaning it likely won’t result in excess gas or bloating. It’s suggested to take a serving of two caplets with at least 8 ounces of water. Taking these caplets without sufficient fluids could increase the risk of choking.
Potential Flaws
- This supplement contains artificial coloring and other additives, which some may prefer to avoid.
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Cons
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Large capsules
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Contains additives
Key Specs
Fiber Source: Calcium polycarbophil | Serving Size: 2 caplets | Fiber per Serving: 1 gram | Other Ingredients: Caramel, crospovidone, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, silicon dioxide, sodium lauryl sulfate
Who It’s For
Best for those who are experiencing symptoms of IBS.
Why We Love It
There are various forms of IBS, including IBS-D (diarrhea), IBS-C (constipation), and IBS-M (a combination). Depending on the form of IBS you have, different supplements may be appropriate for your needs. FiberCon’s Fiber Therapy contains calcium polycarbophil, a non-fermenting bulk-forming laxative. Calcium polycarbophil is an insoluble fiber that behaves similarly to a soluble fiber. Research suggests that it is helpful for those prone to both constipation and diarrhea.
In addition to its versatility, it’s also easy to use. One dose of this supplement for adults is only two capsules once per day. It should be noted that it is important to take it with at least 8 ounces of water. We also appreciate its budget-friendly price.
Potential Flaws
- The capsules are on the larger side and may be more difficult for some to take.
- This supplement contains additives that some may prefer to avoid.
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Key Specs
Fiber Source: Psyllium husk | Serving Size: 5 capsules | Fiber per Serving: 2 grams | Other Ingredients: Gelatin
Who It’s For
Best for those experiencing symptoms of diverticulosis.
Why We Love It
If you have diverticulosis, a condition where small pockets form in the colon, you may benefit from a soluble fiber supplement. Registered dietitian Suzie Finkel, MS, RD, CDN, says, “A high fiber diet has been shown to lower the risk of diverticulitis [inflamed pouches in the digestive tract]. I sometimes recommend a fiber supplement in conjunction [with a high fiber diet], such as a soft bulking agent like ground psyllium husk. This can help to avoid constipation and/or small, hard pieces of stool from getting trapped [in the pockets].”
Metamucil’s Psyllium Supplement only has two ingredients: psyllium and gelatin, which may help with both diarrhea and constipation. We appreciate that it comes in pill form, as psyllium husk can thicken quickly when added to liquids. Like other fiber pill supplements, it is very important to take these capsules with enough water to prevent choking risks. It’s suggested to start with one serving per day, and a healthcare professional may suggest taking it up to four times per day. This product is also available as a powder or as a cracker.
Potential Flaws
- The recommended dose is five pills per serving, which is a lot compared to other options.
- Note this supplement contains gelatin, so it is not suitable for diets that avoid pork products.
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Key Specs
Fiber Source: Acacia fiber | Serving Size: 1 tablespoon | Fiber per Serving: N/A | Other Ingredients: None
Who It’s For
Best for those who want a fiber supplement to help manage symptoms associated with diabetes.
Why We Love It
Research shows that soluble fiber may help manage blood sugar. According to registered dietitian nutritionist Jonathan Valdez, MBA, RDN, CDN, CCM, CDCES, ACE-CPT, “Soluble fiber has the most benefit for [people with diabetes], since it slows the digestion and absorption of carbs in the body, leading to improved blood sugar control and fewer spikes in blood glucose and insulin.” Valdez says it’s ideal to turn to whole food sources of fiber first since whole foods also contain antioxidants, vitamins, and minerals. However, a supplement can be a great way to boost your intake if this proves challenging.
While psyllium husk and beta-glucan are the most well-studied functional fibers for improved glycemic control, acacia powder is another soluble fiber option. NOW Foods’ Acacia Pure Powder only contains organic acacia fiber—a soluble prebiotic fiber that may benefit those with diabetes, promoting the feeling of fullness and modulating blood sugar. This unflavored powder can be easily dissolved in water, smoothies, soups, and other soft foods. We also like that NOW Foods performs extensive in-house testing on its supplements. This product is allergen-friendly and vegan, making it a suitable choice for many with specific dietary needs.
Potential Flaws
- Powder supplements may be less convenient, especially for those who want to take them on the go.
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Key Specs
Fiber Source: Polydextrose | Serving Size: 2 gummies | Fiber per Serving: 3 grams | Other Ingredients: Water, sorbitol, blend of oils with beeswax, colors (purple carrot juice concentrate, turmeric), malic acid, natural flavors, sucralose
Who It’s For
Best for kids who are experiencing constipation.
Why We Love It
Similar to adults, children need adequate fiber for digestive and overall health. Jennifer Friedman, MS, RD, a pediatric dietitian, says, “Fiber can be one of the trickier foods for kids to get through their diets because it’s primarily found in whole grains, beans and legumes, fruit, and vegetables—typically not a child’s most preferred foods, especially picky eaters.” Friedman says that if your child is not able to get enough fiber from food or if they are experiencing constipation, you may want to consider fiber supplements. Remember that fiber supplements haven’t been studied as well in children, so it is always best to check with a healthcare provider first. They can also help you determine what type of fiber would be most appropriate.
L’il Critters’ Fiber Gummy Supplements is a supplement your kids will love adding to their routine. The recommended dose is two gummies for individuals aged 2 and above, providing 3 grams of fiber. The brand is USP-verified, so this supplement is independently verified for ingredient amounts and contaminants. Plus, it’s free from artificial flavors and dyes. Friedman says that fiber in supplements often comes from different sources, so she recommends experimenting to see which fiber source and supplement type agree best with your child.
Potential Flaws
- These gummies are sweetened with sorbitol and sucralose. You should note that sorbitol is a sugar alcohol, which may cause GI upset in some people.
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Key Specs
Fiber Source: Chia seeds | Serving Size: 1 tablespoon | Fiber per Serving: 3 grams | Other Ingredients: None
Who It’s For
Best for those who want a flavorless fiber supplement that can be easily added to many foods.
Why We Love It
If you’re looking for a fiber supplement you can easily add to your daily routine, consider Navitas Organics’ Chia Seeds. These incredibly versatile seeds contain 3 grams of plant-based fiber for every tablespoon. Chia seeds don’t have any flavor and can be added to smoothies, yogurt, oatmeal, salads, and more.
Since chia seeds are high in soluble fiber, they absorb water and swell, forming a gummy, pudding-like texture. Because of this, chia seeds should be eaten with fluids. Additionally, chia seeds are a source of omega-3s and minerals, including calcium, iron, and magnesium.
Potential Flaws
- Some may not like the gummy, pudding-like consistency chia seeds can have when combined with a liquid.
Types of Fiber
- Soluble fiber dissolves in water, forming a gel-like consistency in the gut that can help to slow digestion and promote fullness. Examples include oatmeal, psyllium husk, and flaxseeds.
- Insoluble fiber does not dissolve in water but adds bulk to the stool to promote regularity. Sources include whole grains, nuts, and seeds.
- Functional fibers are defined by the Institute of Medicine as “isolated, non-digestible carbohydrates that have been shown to have beneficial physiologic effects in humans.” These benefits include lowering cholesterol, improved blood sugar management, and bowel movement regulation, depending on the type of functional fiber. Examples include psyllium husk, methylcellulose, calcium-polycarbophil, wheat dextrin, and inulin. They are not intended to replace dietary fiber intake from whole foods, which come with the added benefits of other nutritional properties.
Are Fiber Supplements Beneficial?
If you consume adequate amounts of dietary fiber and experience digestive regularity, you may not need a fiber supplement. If you have diarrhea, constipation, IBS, or another gastrointestinal issue, functional fiber supplements may or may not help. We recommend speaking to a healthcare provider to understand the underlying cause of the issue and to determine whether a fiber supplement would be appropriate.
There are certain situations in which fiber supplements may be beneficial. These include:
- Those experiencing diarrhea: According to Finkel, if you have diarrhea and are considering fiber supplementation, you may benefit from a soft bulking agent that can act like a sponge in the bowel. These products are often mostly soluble fiber, which gel or swell with water. The appropriate product choice, however, will depend on what is driving the diarrhea.
- Those experiencing constipation: Finkel says if you’re constipated, it can be helpful to first look at the diet to ensure you consume adequate fiber from food. If you are getting enough fiber in your diet, adding more fiber from a supplement may not always be helpful for all constipation problems. If your diet could use a fiber boost, products such as psyllium husk can help gently bulk up stool and make it easier to pass.
- Those with IBS: If you have IBS, Finkel says to first consider diet changes and whether the symptoms are mainly diarrhea or constipation. There is evidence for using a soluble fiber supplement in IBS management. You may also want to avoid products with ingredients that can cause gas and bloating, such as sugar alcohols or inulin.
- Those with high cholesterol: Soluble fiber may help lower levels of LDL cholesterol (“bad cholesterol”) by binding with cholesterol and removing it in the feces. If a healthcare provider has determined you have high cholesterol, you may want to discuss whether fiber supplementation is appropriate.
- Those with diabetes: Fiber supplements may benefit those with type 2 diabetes by reducing fasting blood sugar and HbA1c. If you have diabetes, speak to a healthcare provider about fiber supplementation, particularly if you take medications.
Who May Not Benefit from Fiber Supplements
Fiber supplements should not replace a balanced diet high in fiber-rich foods. There are also certain situations in which you should exercise caution with fiber supplements. You should avoid fiber supplements if you:
- Consume adequate fiber: If you eat enough dietary fiber, a fiber supplement may not be necessary. Excessive fiber intake can lead to gastrointestinal issues such as gas, bloating, diarrhea, or constipation. This can occur when you add too much too soon or do not consume enough liquids.
- Are taking certain medications: Fiber supplements can lower absorption of certain medications. If you are taking medications, including those for diabetes management, consult a healthcare provider before using fiber supplements.
- Have intestinal obstructions or fecal impact: Avoid bulk-producing laxatives if you have intestinal obstructions, as they can exacerbate the problem. You should first focus on treating the underlying condition under the guidance of a healthcare professional.
- Have inflammatory bowel diseases such as ulcerative colitis or Crohn’s disease: If you have an inflammatory bowel disease, you should speak with a healthcare provider before using fiber supplements.
How We Selected the Fiber Supplements
Our team works hard to be transparent about why we recommend certain supplements; you can read more about our dietary supplement methodology here.
We support supplements that are evidence-based and rooted in science. We value certain product attributes that we find to be associated with the highest quality products. We prioritize products that are independently verified and certified by one of three independent certifiers: USP, NSF, or ConsumerLab.com.
We also spoke with a gastrointestinal dietitian, a pediatric dietitian, and a registered dietitian nutritionist about what to look for when shopping for a high-quality fiber supplement and what to avoid.
It’s important to note that the FDA does not review dietary supplements for safety and effectiveness before they go to market. Our team of experts has created a detailed, science-backed methodology to choose the supplements we recommend.
What to Look For
Independent Verification
Supplements that are independently verified are sent to a lab where they are tested to ensure they contain what they say they contain and are not contaminated with specific high-risk, common contaminants. However, it’s important to note:
- Independent verification does not test to see if a product is effective or safe for everyone, and it does not ensure the supplement will not interact with other supplements or medications.
- Not all independent verification is created equal. It is not uncommon for supplement companies to pay labs for certificates after conducting minimal to no testing.
- The certifications we can trust are: ConsumerLab.com, NSF, and USP. However, these certifications are difficult to obtain and/or expensive for manufacturers, so many companies choose not to get their products tested by one of these three organizations.
- Sometimes products tested by these three companies are more expensive to try to offset the cost they pay for certification.
- Just because a supplement is not tested by one of these three companies does not mean it’s a bad product. We recommend doing some research on the reputability of the manufacturer and calling up the manufacturer and their testing lab to determine their protocols and decide if you feel comfortable consuming the supplement.
Contamination with heavy metals such as lead, arsenic, and cadmium may be a risk with certain fiber supplements. Psyllium husk has been found to be contaminated with lead, so we chose one that has been tested and approved by ConsumerLab.com. However, most fiber supplements are not independently verified.
Form
Fiber supplements come in a variety of forms, including capsules, powders, or gummies, each with its own benefits and drawbacks. Capsules may be easy to take, but the serving size can vary between supplement brands. In some cases, many pills may be needed to meet your required dose. In addition, capsules need to be taken with adequate fluids and may not be best for people with swallowing difficulties.
Powder fiber supplements can often be added to liquids or soft foods, but some can thicken quickly in liquid, making them more suitable for baked goods. Gummies may contain added sugars or sugar alcohols, which may or may not suit your needs.
Ingredients and Potential Interactions
It is essential to carefully read the ingredient list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included relative to the recommended daily value of that ingredient. Please bring the supplement label to a healthcare provider to review the different ingredients contained in the supplement and any potential interactions between these ingredients and other supplements and medications you are taking.
It is important to review ingredient labels, as some fiber supplements may contain additional ingredients that can result in GI upset. If you experience IBS, you may want to avoid products with ingredients such as sugar alcohols, inulin, or chicory root, as these can lead to gas or bloating for some.
If you have diabetes or are managing your blood sugar levels, be aware fiber supplements can impact blood sugar levels and potentially interfere with diabetes medication. You may also want to check whether products contain added sugars. If you have diabetes, check with a healthcare professional before adding a fiber supplement.
Fiber supplements can also interact with your body’s ability to absorb certain medications, including tricyclic antidepressants, diabetes medications, carbamazepine, digoxin, or lithium. You may need to take medications one hour before or two to four hours after fiber supplementation. If you are taking medications, you should consult with a healthcare provider before incorporating fiber supplements.
Fiber Dosage
According to the 2020-2025 Dietary Guidelines for Americans, daily dietary fiber recommendations are as follows:
- Ages 2 to 3: males and females — 14 grams
- Ages 4 to 8: males — 20 grams, females — 17 grams
- Ages 9 to 13: males — 25 grams, females — 22 grams
- Ages 14 to 18: males — 31 grams, females — 25 grams
- Ages 19-30: males — 34 grams, females — 28 grams
- Ages 31-50: males — 31 grams, females — 25 grams
- Ages 51+: males — 28 grams, females — 22 grams
You should first focus on meeting your fiber needs through whole foods sources and consult a healthcare professional before turning to a fiber supplement.
How Much Is Too Much?
There is no Tolerable Upper Level for dietary fiber. However, consuming too much fiber can result in GI disturbances such as gas and bloating, so it may be best to consult a healthcare provider to determine the appropriate dose for your needs. It is important to increase your fiber intake gradually along with increasing fluids accordingly to minimize GI discomfort when increasing fiber.
Our Experts
Our team of registered dietitians spoke with additional experts throughout the research, selecting, and reporting process. The following experts spoke with us about what key features to look for when shopping for a high-quality fiber supplement, its benefits, and who they may be helpful for. While we select products independently, expert input influences our decisions.
- Suzie Finkel, MS, RD, CDN, gastrointestinal dietitian at New York Gastroenterology Associates
- Jonathan Valdez, MBA, RDN, CDN, CCM, CDCES, ACE-CPT, registered dietitian nutritionist, certified personal trainer, and founder of Genki Nutrition
- Jennifer Friedman, MS, RD, pediatric dietitian and founder of Jennifer Friedman Nutrition
Frequently Asked Questions
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Are there different recommendations for fiber supplements for women versus men?
Yes, men, in general, have a higher recommended intake of fiber. The Academy of Nutrition and Dietetics recommends that adult men obtain around 35 grams of fiber per day and adult women obtain 28 grams of fiber per day. Whether for men or women, we recommend first turning to whole food sources of fiber such as fruits, vegetables, nuts, whole grains, and whole grain products to meet your needs. If you can meet your daily requirements, you may not need a fiber supplement.
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Do fiber supplements make you poop more?
Depending on the type of fiber supplement you’re using, fiber supplements can help regulate your bowel movements. In general, consuming enough dietary fiber and prioritizing adequate hydration can improve bowel regularity. Additionally, some functional fibers may help to alleviate constipation including psyllium, methylcellulose, calcium-polycarbophil, and coarse wheat bran. Psyllium husk is the most researched-backed functional fiber for regularity, so we recommended trying Yerba Prima Psyllium Husks Powder.
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Can fiber supplements make you constipated?
Fiber supplements should be taken with adequate water and often must be incorporated into the diet gradually. Increasing your fiber intake rapidly or doing so without adequate water intake can lead to bloating, gas, and cramping and could lead to constipation.
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Can fiber supplements cause diarrhea?
Fiber supplements taken improperly may contribute to diarrhea. This might occur if you are taking a fiber supplement high in insoluble fiber or if you increase your fiber intake too quickly. It is important to understand the type of fiber you need and to allow your body some time to adjust.
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Are all fiber supplements beneficial for health?
Fiber is an important nutrient that can benefit digestive health and have broader impacts on overall health. If you are consuming adequate amounts of dietary fiber, you may not need a fiber supplement. Not all fiber supplements benefit each individual, and some may exacerbate certain issues. If you are uncertain whether a fiber supplement would be helpful for you, we recommend speaking with a healthcare provider.
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What is the difference between prebiotics and probiotics?
Probiotics are live bacteria that can help support a healthy gut microbiome. They are considered “good bacteria” that help to keep harmful bacteria in check, supporting an optimal gut flora balance. They also break down fiber, release beneficial byproducts, and help to support your body’s immune response. They can be found naturally in yogurt and other fermented foods, as well as in supplement form.
Prebiotics are non-digestible fibers that help to feed beneficial, live bacteria (probiotics) in the digestive tract. The two most common prebiotics found in supplements and foods are fructo-oligosaccharides (FOS) and galactooligosaccharides (GOS), both fermentable, soluble fibers. In supplements, you can often find these in the form of inulin and chicory root. While these fibers help to feed good bacteria, they do not necessarily help to mitigate diarrhea or constipation directly. They can cause gastrointestinal side effects like bloating, gas, and abdominal discomfort, particularly in those with IBS.
In general, consuming both prebiotics and probiotics can help support a healthy and thriving gut microbiome, which is typically associated with improved digestion and other favorable health outcomes. While it is best to consume a variety of fiber and probiotic sources from food by incorporating a diet rich in plants and fermented foods, prebiotic and probiotic supplements can help boost your intake.
Why Trust Verywell Fit
Tamar Kane, MS, RD, is a Registered Dietitian, Verywell Fit nutrition writer, and marathon runner. She is the founder of Tamar Kane Nutrition, a virtual practice that focuses on helping runners learn to fuel their running and their lives. Tamar has her master’s degree in Nutrition and Exercise Physiology from Teachers College, Columbia University, and specializes in working with plant-based athletes. Her goal is to help people understand how to properly fuel their bodies (and supplement if needed!) to optimize performance and well-being.
Additional reporting contributed by Eliza Savage, MS, RD, CDN, RYT
Eliza Savage, MS, RD, CDN, RYT, is a registered dietitian and Verywell Fit writer with a lifelong passion for wellness. Eliza has covered nutrition and fitness topics, testing products such as bone broth, Greek yogurt, and more. She has also written about gym equipment and sports, such as pickleball.
