We asked dieticians the best fiber supplements to take in 2026

Given just how quickly “fibermaxxing” — or the idea of maximizing dietary fiber intake — proliferated online last year, it’d be easy to write it off as just another viral diet trend. And while there is such a thing as too much fiber, the truth is that most Americans aren’t getting enough of the carbohydrate, says Elisabetta Politi, CDCES, MPH, RD, a registered dietician at Duke Health. (The Academy of Nutrition and Dietetics recommends 14g for every 1,000 calories consumed, which is typically around 24g to 38g per day.)

“Fiber is a really important component of the diet that has historically been overlooked,” says Olufemi Kassim, MD, a gastroenterologist at Northwestern Medical Group. “It’s basically the leftover stuff from fruits and vegetables that isn’t fully digested and helps your bowels move. You can get fiber from natural sources, like fruit, vegetables, or whole grains, or from supplements.”

“Fiber can reduce the risk of heart disease and type 2 diabetes, lower cholesterol, support blood sugar management, provide satiety, reduce constipation, and may lower the risk of several types of cancer,” adds Jane Haas, RD, with Kristie Tovar Nutrition & Associates. “It also feeds the bacteria we have in our gut: When fermentable fiber sources are broken down by these microbes, short-chain fatty acids are produced, which help support gut health and digestion.”

It’s ideal to get your fiber from food sources, since then you’re also “getting all the other micronutrients and nutritional benefits from the fiber sources, which tend to be very nutrient-rich,” says Dr. Kassim. But some people may struggle to get enough fiber in their diet for a variety of reasons, which can result in feeling a bit clogged up.

That’s where supplements come in. Here’s what you need to know about fiber, how to know if you’re getting enough, and whether you might benefit from a supplement.

What is fiber?

“Fiber is an umbrella term for types of carbohydrates that we cannot fully digest, but that give us health benefits nonetheless,” says Jennifer Bruning, MS, RDN, LDN, a dietician and spokesperson for the Academy of Nutrition and Dietetics.

Rather than being broken down by the gastrointestinal tract, fiber passes from the small intestine into the colon undigested. “That’s what helps give your stool bulk — that’s what keeps things moving,” says Dr. Kassim.

There are two types of fiber: soluble fiber, which may help lower cholesterol, says Politi, and insoluble fiber, which does that all-too-important work of preventing constipation. Beans, peas, legumes, artichokes, leafy greens, sweet potatoes, winter squash, nuts, seeds, berries, pears, apples, and whole grains are all great sources of fiber.

While 24g of fiber may not sound like much, getting enough actually requires some intentionality. For instance, a medium-sized apple with the skin on only has around 3g or 4g of fiber, and a cup of broccoli has 5g or 6g. “People will think they’re getting enough fiber because they have a salad at lunch time, or they have a banana, but you really do need quite a bit,” says Dr. Kassim. Plus, many foods in the standard American diet are low in fiber, points out Bruning, such as white bread, fried potatoes, snack foods, and protein-rich foods.

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Should you take a fiber supplement?

Infrequent bowel movements and constipation are classic signs that you could use more fiber. But Dr. Kassim says that too frequent bathroom visits — like more than three times per day — is another lesser-known indicator. “It sounds counterintuitive, but if you’re going too frequently, it sometimes means that your stools are too small and don’t have enough bulk in them,” she says.

Feeling hungry all the time is another indicator that you aren’t eating enough fiber, and Bruning says that lab results indicating high cholesterol are also a sign that your blood sugar could use a more fiber-heavy diet.

If you’ve determined that you aren’t getting enough fiber, don’t go straight for the supplement aisle. “While supplements can be convenient and helpful to top off a daily fiber goal, focus on fiber in food first,” says Bruning. “Try to make small shifts in your diet to increase your daily fiber before defaulting to a supplement.”

A registered dietitian nutritionist (RDN) can help with this process, says Bruning, and can assist in determining how much more fiber you need to be eating, and whether some of this might need to come from a supplement.

Common reasons why a supplement may be necessary include a restrictive diet, a busy lifestyle, or an intolerance of high FODMAP foods (a category of high-fiber foods, including beans, lentils, apples, and wheat-based products) that can cause intestinal distress in some people. Dr. Kassim says she also recommends supplements for some patients who are meeting their recommended daily fiber goals, but still struggle with issues like diverticulosis or anal fissures.

Whether you’re increasing your fiber intake through food or supplements, start slowly, recommends Politi, and make sure you are also increasing your fluid intake.

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What to look for in a fiber supplement

There’s an abundance of fiber supplements to choose from, whether you’d prefer a powder (which has the bonus of keeping you hydrated but can have an unpleasant taste), a convenient tablet or capsule, or a gummy (a solid choice as long as you don’t mistake them for candy and overconsume).

Fiber supplements can contain various additives. While Dr. Kassim says that most fiber supplements on the market will do the job, keep an eye out for any ingredients you may be allergic to or intolerant of, and for any supplements with lots of additives (like sweeteners or flavors). Keep dosage in mind, as taking too much fiber or increasing intake too quickly (especially without water) can result in bloating, gas, diarrhea, or constipation. A RDN can help you determine the best dosage for your body.