A fiber supplement is a powder, capsule, or gummy that provides the fiber necessary to compensate for today’s high-carb, low-fiber diets.
Fiber does more than just prevent constipation and diarrhea. Studies show it can also modulate blood sugar, lower blood pressure, reduce cholesterol, and prevent the development of certain types of cancer.
We researched more than 100 popular fiber supplements and concluded that the following represent the best fiber supplements of 2021.
1. NOW Supplements Psyllium Husk Powder
That NOW would produce an outstanding fiber supplement should be no surprise. They’ve been providing a variety of high-quality supplements since 1968. Their Psyllium Husk Powder is clean, simple, and very effective.
What we like: NOW Psyllium Husk Powder is rigorously tested at every phase of production to ensure no genetically modified organisms find their way in. Each serving contains 6 grams of organic psyllium husk powder. That’s it.
Flaws: If we had to nitpick, we might say there are too many carbs for keto dieters.
2. Metamucil Psyllium Husk Capsules
Metamucil makes some of the most popular fiber supplements ever created. They have decades of experience and a spotless reputation for quality and efficacy. Their Psyllium Husk Capsules are a convenient way to get the added fiber you need.
What we like: The size of each capsule is kept modest (2 grams) because the product is intended to be used by kids as young as 12. These are low-carb, low-calorie, sodium-free capsules that will work with just about anyone’s diet.
Flaws: Taking five capsules per day as directed might be too much for some folks.
3. Kirkland Signature Optifiber
Kirkland Signature Optifiber contains wheat dextrin, which is derived from wheat starch and is highly regarded by health professionals for its ability to reduce cholesterol and promote a healthy gut biome.
What we like: Wheat dextrin often gets lost in the shadow of psyllium husk, and that’s a shame because many dieticians consider it just as effective. Kirkland Signature Optifiber wheat dextrin is sugar, lactose and gluten-free, and easy to drink.
Flaws: You need to stir it really well when adding it to a cold beverage.
4. Viva Naturals Organic Psyllium Husk Powder
Viva Naturals Organic Psyllium Husk Powder is certified organic, gluten-free, and vegan. It’s pure psyllium husk ground to perfection, and you don’t need to take it four or five times a day. Once or twice should do it for most people.
What we like: This is a simple, pure product composed of psyllium husk and nothing else. Not even a dash of salt or sugar. Just GMO-free organic psyllium. Take it with eight ounces of water for maximum effect.
Flaws: It works, but does not mix as well as some others.
5. Garden of Life Super Seed
Garden of Life Super Seed is derived from organic flaxseed, chia seed, and about a dozen other high-fiber ingredients chosen for their nutritional value. Super Seed is also rich in probiotics for restoring and maintaining a healthy digestive tract.
What we like: This is one of the most comprehensive fiber-rich ingredient lists you will find. As an added bonus, each serving contains 66 mg of calcium. Super Seed is an outstanding source of both soluble and insoluble fiber.
Flaws: Thickens up pretty quickly after mixing.
6. Swanson Tri-Fiber Complex
Swanson Tri-Fiber Complex is a sound choice for people on the go. Not everyone has the time or the opportunity to stop and mix a glass of fiber powder. For those folks, an easy to swallow, high-fiber, gluten-free capsule like this can be a life saver.
What we like: Swanson Tri-Fiber contains equal amounts of psyllium husk and oat bran fiber, along with a smattering of highly beneficial apple pectin. But don’t worry, there’s no sucrose in that apple pectin. Only fiber.
Flaws: Need to drink a lot of water or it won’t be so effective.
7. Phillips’ Fiber Good Gummies
Sometimes you don’t want to be bothered with mixing fiber powder in a glass or taking a big capsule. But you still need your fiber. In those cases, Phillips’ Fiber Good Gummies are an ideal choice. They have a light, natural taste and melt in your mouth while you chew.
What we like: Phillips’s Fiber Good Gummies contain inulin, which doubles as both a fiber and as a prebiotic that helps maintain a healthy gut microbiome. They can be used by kids as young as four too.
Flaws: They use animal-derived gelatin so vegans beware.
8. Nestle NutriSource Fiber
Each scoop of Nestle NutriSource Fiber provides 3 grams of little-known guar gum fiber to restore a healthy gut environment and keep things moving in a timely fashion.
What we like: Guar gum fiber does not get the kind of press that psyllium does. Nonetheless, it is prized by those in the know for its ability to absorb excess liquids and correct diarrhea and soften stools and alleviate constipation.
Flaws: Tends to sell out fast.
9. Navitas Organics Chia Seeds
Whole chia seeds are 40% fiber, which makes them an excellent fiber supplement. Navitas Organics Chia Seeds are certified Kosher, organic, vegan, and GMO-free. They’re also gluten-free and contain zero sodium.
What we like: This is not a powder. These are whole seeds that can be added to salads, dips, baked goods, and more and will provide the fiber you need along with calcium, magnesium, and iron.
Flaws: They need to be hydrated before using.
10. Heather’s Tummy Fiber
Heather’s Tummy Fiber is 100% acacia senegal fiber. Acacia senegal is a whole soluble fiber that is also an effective prebiotic. So not only will things get moving in your digestive tract, but that digestive tract will be more efficient than ever.
What we like: Heather’s Tummy is likely a very happy place because the acacia senegal fiber is a great source of prebiotics. As such, it’s more than your standard fiber supplement. It can also help in dealing with nutritional shortfalls, IBS, and more.
Flaws: The new packaging is kind of flimsy.
Who Needs a Fiber Supplement?
Everyone needs fiber to maintain a healthy gut microbiome and to ensure food and waste move through the digestive system in a timely fashion. Unfortunately, researchers believe that only about 5% of Americans are getting as much fiber as they actually need (1). This results in millions of people every year suffering from constipation and nutrient deficiencies.
Of course, if you already eat a diet that includes plenty of leafy greens and other forms of dietary fiber, then in all likelihood, you do not need to take a fiber supplement. But you would be the exception. For most of us, we have two choices: either increase the amount of dietary fiber we get from the food we eat, or take a fiber supplement.
How We Ranked
There are a lot of supplements and other products on the market right now that claim to be high in fiber. But we are only interested in those specifically designed to deliver high-quality fiber for the purposes of achieving and maintaining a healthy digestive tract and promoting regularity.
That means you won’t find things such as high fiber protein powders on our list. Because they are formulated to address the needs of the bodybuilder, of which adequate fiber is only one. Using such a product strictly for the fiber, without engaging in rigorous strength training, would likely produce little besides enormous love handles.
The type of fiber was also important. Psyllium is generally considered to be the gold standard of fibers because it is pure and simple and gluten-free and known to be highly effective for most people. But there are other types of fiber that are also safe and effective, such as chia seeds, wheat dextrin, and more. So our list is not confined to psyllium.
We also wanted to include a range of delivery methods, which means fiber capsules, gummies, and powders, simply because not everyone’s preferences are the same. Powders, however, needed to be free of artificial flavors, colors, preservatives, and sweeteners. If a sweetener was used, we gave the nod to a natural one like stevia over something like cane sugar.
Finally, we sifted through mountains of user reviews to see if we could identify any positive or negative trends within the feedback. After all, if a thousand people say something works, against only a few who say it does not, that deserves to be considered.
Fiber supplements ensure regularity. Everybody takes regularity for granted until it disappears. When your formerly regular bowel movements turn into a twice-weekly ordeal, or amount to nothing more than a bit of loose material being passed several times a day, it’s time to reach for the fiber supplements. Fiber supplements can loosen up rock hard stools and get them moving, or add bulk to watery stools and put things back on schedule.
Fiber helps you maintain a healthy weight. If you want to stay at your current weight, fiber can help. Fiber tends to fill up your stomach because most of it cannot be digested. It also takes its time moving from your stomach through your intestines, all the while creating a sense of satiety. This feeling of being full has the effect of preventing you from overeating.
Fiber can also help you lose weight. If you are on a weight loss program, fiber supplements can help too. First, because they produce the aforementioned feeling of satiety, which should make it easier for you to limit how much you eat. And second, because fiber can bind with fat molecules in your gut (2) and carry them out of your system before they can be absorbed and turned into extra inches around your waist.
Fiber supplements can reduce the risk of developing type 2 diabetes. Numerous studies have confirmed that people who eat a diet high in fiber have less of a chance of developing type 2 diabetes than those who eat less fiber (3). How does fiber do this? Well, by keeping you regular, by binding with fat molecules and evacuating them from your system, and by allowing you to manage your weight.
Fiber is important for maintaining bowel health. Fiber not only helps restore and maintain regular bowel movements, but it also helps restore and maintain healthy bowels. It is never a good thing if you are unable to defecate for a protracted period of time (4). It can lead to all kinds of problems, from distended bowels to ruptured bowels and even malnutrition, since people who are constipated often lose their appetite.
Fiber can help prevent diverticulitis. Speaking of constipation, when food lingers in your colon it can lead to the formation of pouches on the intestinal wall. If these become infected, as they often do, you wind up with diverticulitis (5). Diverticulitis can be painful and produce fundamental changes in your bowel movements. By helping to keep things moving through your entire digestive tract, fiber can prevent diverticulitis.
Fiber may help lower cholesterol levels. Soluble fiber, like that found in fiber supplements, can help lower the amount of ‘bad’ low-density lipoprotein (LDL) cholesterol in your bloodstream. Soluble fiber prevents LDL cholesterol from being absorbed during the digestive process (6). Instead of mucking up your veins, the cholesterol is harmlessly expelled during bowel movements.
Fiber may help lower blood pressure. Researchers looked at data from more than two dozen health studies related to the effects of dietary fiber and concluded that a high fiber diet can have a beneficial effect on blood pressure (7). The precise mechanism behind this benefit is not yet completely understood, but the evidence supporting the notion of a fiber/lower blood pressure connection is irrefutable.
Fiber is good for your heart. As is the case with fiber and lower blood pressure, the link between fiber consumption and a lack of heart disease is real, though not yet fully understood (8). It is believed fiber produces this benefit via its ability to reduce serum cholesterol by binding to it (as mentioned above) and moving it out of your system via bowel movements. Both soluble and insoluble fiber have a hand in producing this benefit.
Fiber supplements can prevent blood sugar spikes. Soluble fiber has a lower glycemic index (9) than other types of food. By increasing the amount of fiber in your diet, you can reduce harmful blood glucose spikes that often occur after eating other types of carbohydrates. Increased fiber intake is, in fact, recommended for diabetics and prediabetics as a way to gain greater control over their levels of blood glucose (10).
Fiber supplements prevent constipation. Constipation affects millions of Americans. It is defined as having fewer than three bowel movements per week, with stools that are hard and often difficult to pass. Dehydration is a common cause of constipation, but so too is a lack of fiber. A meta analysis of more than 60 years of studies (11) concluded there is no doubt that increased fiber consumption produces more frequent bowel movements.
Fiber promotes a healthy gut microbiome. Turning food into energy and bodily tissue is an extremely complicated process. One that relies heavily on what scientists call the ‘gut microbiome’. A major component of the gut microbiome is bacteria called ‘probiotics’ that live in the digestive tract and extract nutrients from the food you eat. These probiotics need fiber to fuel their activity. Without it, your overall level of nutrition suffers.
Fiber may reduce the risk of certain cancers. This is especially true when it comes to colorectal cancer. A study published in 2016 looked at whether increased fiber intake could prevent women from developing colorectal cancer. The conclusion was that fiber can reduce the risk (12). But recent research (13) suggests fiber may also have a role to play in reducing the risk of breast cancer, ovarian cancer, and other types of cancer as well.
Fiber promotes proper hydration. Dehydration is a serious problem (14). One that often contributes to constipation. When you take a fiber supplement, you should also drink more water than you normally do. In fact, any reputable fiber supplement will state clearly on the label that you should drink plenty of water when you take it. So, by promoting increased water consumption, your fiber supplement is helping you maintain proper hydration levels.
Fiber acts as a type of natural detox. People spend lots of time and money researching, buying, and using things like juice cleanses to detox their system. But all they usually need is more fiber in their diet. Fiber is nature’s own detox. It scours the digestive tract of toxins and absorbs fats and other harmful compounds before they can be metabolized and cause short and long term harm.
Fiber supplements are good for your bones. Some soluble fibers are also ‘prebiotics’ and serve the important purpose of providing fuel for the ‘probiotics’ that drive digestion. Prebiotic fiber enhances your system’s ability to process and incorporate calcium (15), which plays an essential role in maintaining healthy bones as we age. A lack of calcium is a major factor in the development of osteoporosis (16).
Fiber supplements are convenient. It’s not always possible to get out to the supermarket and get all the fresh vegetables you need. Nor do busy people necessarily have the time to prepare healthy, high-fiber meals. This is where fiber supplements come in. Fiber supplements are easy to obtain, easy to store and easy to take. They fill a crucial dietary gap that can help you maintain a higher level of overall health at a time when that has never been more important.
Fiber supplements are affordable. One of the many great things about fiber supplements – besides their many health benefits and their convenience – is that they are well within most peoples’ budget. For just pennies per day, you can get the fiber you need to keep your blood sugars, cholesterol, and blood pressure in check, to help you maintain a healthy weight (or even lose weight), and perhaps to fend off several types of cancer.
Fiber may help you live longer. This is no empty marketing claim. It’s a fact. Because fiber can improve the efficiency of your digestive tract, because it can help you maintain bone density and avoid devastating fractures, because it can help you avoid developing colon cancer, and because it can lower blood pressure and cholesterol levels, it can help you live a longer, healthier life.
Q: What is fiber?
A: Fiber is a type of food that has little nutritional value but is crucial to proper digestion and to maintaining regular bowel movements. Carbohydrates, fats, and proteins are broken down by the digestive system and the nutrients absorbed to provide energy and facilitate cell production. Not fiber. Insoluble fiber moves through your digestive tract largely untouched. At the same time, soluble fiber is used as fuel by the bacteria in your gut that metabolize nutrients.
Q: Why do I need a fiber supplement?
A: It is recommended that people get between 20 and 35 grams of fiber per day. Exactly how much depends mostly on the size of the person and how much food they eat every day. But as a general rule, it is recommended that the average woman get 25 and the average man 38 grams of fiber per day (17). The problem is, researchers believe the average American only gets 12-15 grams. That is why you probably need a fiber supplement.
Q: How long does it take a fiber supplement to relieve constipation?
A: Some folks only take a fiber supplement when they experience constipation. In such cases, it should take anywhere from 24 to 48 hours for the fiber supplement to relieve constipation. The best approach, however, is to make a fiber supplement a part of your regular dietary intake. That will help keep constipation at bay and deliver the other benefits we listed above.
Q: Is the fiber in supplements the same as the fiber in a salad?
A: Not really. The fiber in something like a salad is provided in its natural state and is able to clean your digestive tract a bit more effectively as a result. Also, if you are eating salads and other high fiber foods, you probably are not eating much junk food, which is obviously a good thing. That said, the differences between natural fiber and fiber supplements are not substantial, and fiber supplements are a far superior option to not getting any fiber.
Q: What is psyllium?
A: ‘Psyllium’ or ‘psyllium husk’ are words you will read and hear a lot when researching fiber supplements. Psyllium sounds like something used to make nuclear weapons, but in fact, it is the name of a fairly unremarkable type of plant whose seeds are prized for the high fiber content of their husks. Psyllium is great for relieving constipation and diarrhea (18) and is one of the most common ingredients in commercial fiber supplements.
Q: Can I take a fiber supplement every day?
A: Yes, you can safely take a fiber supplement every day. There is no evidence that fiber supplements produce adverse effects when taken regularly. In fact, the opposite is true. Fiber supplements can also be taken occasionally if you are suffering from constipation or diarrhea. Although the best approach is to take fiber every day in order to prevent constipation or diarrhea from happening in the first place.
Q: I am not eating excessive amounts of fiber, why am I gassy?
A: Flatulence is often the result of consuming more fiber than you need. But in some cases, people will experience gas even when they adhere to the recommended dosage. When this happens, it is usually because a person is just starting out with a fiber supplement. Their body just needs time to adjust to the new normal. Given time, it should eventually settle down. If the gassiness does not subside, try a different supplement.
Q: What are prebiotics?
A: ’Prebiotic’ is another name for soluble fiber. This type of fiber is used as fuel by the live bacteria in a person’s gut. That may not sound like such a good thing, but the gut is full of beneficial bacteria called ‘probiotics’ (19) that play a crucial role in the digestive process. Without them, a person would essentially starve to death because they would not be absorbing enough nutrients from the food they eat.
Q: Are there any side effects to fiber supplements?
A: When taken as directed fiber supplements typically produce few if any side effects. People who take more than the recommended amount will likely experience bloating or gas, or both. Some will experience diarrhea as the excess fiber is continually moving through their digestive tract. Also, taking too much fiber may result in a shortage of some minerals, as they bind with the fiber and are evacuated during bowel movements.
Q: Are fiber supplements gluten-free?
A: When people adopt a gluten-free diet they also, often inadvertently, adopt a low-fiber diet. That’s because many of the foods that contain gluten are also high in fiber (such as bread, crackers, and cereal). Giving up these foods can produce a significant fiber shortage. Fortunately, you can make up for that shortage with fiber supplements. And most fiber supplements, including psyllium, are gluten-free. Always check the label anyway, just to be sure.
Q: Do fiber supplements contain sugar?
A: No, most fiber supplements are completely devoid of sugar. Some may contain trace amounts of sucrose, if fruits are used as part of the ingredient list. But this is rare. Most fiber supplements contain no naturally occurring or added sugar.
Q: How can fiber help a person lose weight?
A: When you take a fiber supplement, you need to drink plenty of water with it. That water causes the fiber to swell in your digestive tract. That has two effects. First, the swollen fiber takes up space in your gut, producing a feeling of being full, which should help you eat less. And second, fiber is slow to digest, so that sensation of being full tends to linger, preventing most people from wanting to eat as often.
Q: Can fiber really reduce my chance of getting cancer?
A: This seems like a far-fetched marketing claim, but there is ample science to back it up (20). Researchers have known for years that getting enough fiber will reduce the odds of developing colon cancer. But recent large scale studies indicate getting enough fiber in early adulthood may also reduce the risk of developing breast cancer (21). Additional studies are even suggesting fiber may play a role in preventing other types of cancer as well.
Q: Can fiber supplements cause dehydration?
A: They may if you do not drink enough water when taking them. Soluble fiber is very absorbent. So, as a general rule, it is recommended you drink at least one full glass of water when you take a fiber supplement (consult the label on the particular supplement you have to determine exactly how much water to drink). Failing to drink enough water can cause stomach pain as the fiber soaks up what little moisture there is in your digestive tract.
Q: Do fiber supplements interfere with medications?
A: In most cases fiber supplements will not interfere with medications. There are a few exceptions to that rule, however. A fiber supplement may interfere with how aspirin or NSAIDs are absorbed. So you should not take the two things one right after another. Also, because fiber has an impact on both blood glucose and blood pressure levels, you should talk to your doctor before taking fiber supplements if you are being treated for either of those.
Q: Can a fiber supplement lower my cholesterol levels?
A: Yes, a fiber supplement can help lower your cholesterol levels. Numerous health studies over the years have confirmed this. And the US government’s National Library of Medicine recommends people consume more fiber (22) in order to lower the amount of ‘bad’ LDL cholesterol in their system.
Q: What is the best time to take fiber supplements?
A: In most cases, there is no ‘best time’ to take a fiber supplement. That said, if it is recommended you take a particular supplement three times per day, then you will want to spread the doses out and not want to bunch them all together. As we mentioned above, you probably should avoid taking fiber supplements and things like aspirin at that same time too. And, most importantly, always remember to drink enough water when taking fiber supplements.
Q: Can pregnant women take fiber supplements?
A: Yes, pregnant women can and often should take fiber supplements. Constipation is an all-too-familiar problem encountered by pregnant women. Fiber supplements can be a convenient, effective way to either fend off constipation (if taken regularly) or relieve constipation (if taken after the constipation manifests). Psyllium husk fiber supplements are considered a good choice for pregnant women (23).
Q: Are fiber supplements vegan?
A: Some fiber supplements are vegan and some are not. In large part, it depends on the form the supplement takes. Powder supplements that are mixed with water are likely to be void of all animal products (although they may be processed in a facility that also processes animal products for other uses). Gelcaps, however, are sometimes made using bovine gelatin. You will need to check the label carefully before choosing a fiber capsule.
Fiber supplements fill an essential role in helping Americans get the fiber many of them are sorely lacking. But fiber supplements do more than just help a person get and stay regular. They also help reduce cholesterol and blood pressure levels, stabilize blood sugars, prevent certain types of cancer, and much more.
Fiber supplements come in several forms, so there is bound to be one that you find agreeable. Use the above information to determine which fiber supplement is just right for you.
For cpoe.org’s #1 recommended fiber supplement, click here.