Let’s face it, fiber hasn’t historically been the sexiest topic in nutrition. But lately, you may have noticed your favorite health and wellness personalities touting the best fiber supplements. From swirling their morning glasses of psyllium husk to popping a fiber pill with a green juice—fiber is, dare we say, actually kind of buzzy.
And, as it turns out, fiber is pretty essential for your overall health—supporting everything from your digestion to your microbiome, yet most of us aren’t getting nearly enough. That’s where fiber supplements can come in to save the day (and your gut).
We spoke with registered dietitians and doctors for their take on the best ones, from on-the-go powders to easy-to-take capsules. Glamour testers also tried out many of these RD-approved products, evaluating taste, ease of use, and effectiveness. Our top pick is Thorne FiberMend because it’s backed by experts, eases stomach symptoms, and has a subtle taste that blends well in a smoothie. BelliWelli and Benefiber also earned high marks for portability and easy drinking.
The best fiber supplements, at a glance
- Best Overall: Thorne FiberMend, $40
- Best for Constipation: YayDay Supplement, $60
- Best for Bloating: Tomorrow’s Nutrition Sunfiber, $25
- Best for Cholesterol: Metamucil Daily Fiber Supplement, Orange Smooth, $17
- Best for Weight Loss: Pure Encapsulations PureLean Fiber, $50
Your fiber supplement questions, answered
Fiber is a type of carbohydrate that the body can’t digest, and while it doesn’t provide energy the way other carbs do, it plays a crucial role in overall health. Researchers are now learning that different forms of fiber benefit people in different ways, but basically, fiber falls into two main categories: soluble and insoluble. Both are beneficial for the body but serve different functions.
Soluble fiber, which is in oat bran and psyllium husk (derived from the seeds of the Plantago plant), “mixes with water to form a thick gel-like material in our intestines, which then slows digestion and helps to manage diarrhea,” says Angel Luk, a registered dietitian in Richmond, British Columbia. Bonus: It can also help trap fats so they don’t get absorbed by your body, which can help you lower LDL cholesterol (that’s the bad kind) and reduce the risk of heart disease.
Insoluble fiber, on the other hand, absorbs liquids to bulk up your stool. “It sort of acts like a magnetized squeegee because it sticks to other materials to make the stool easier to pass,” says Luk. It’s a lifesaver for regularity and constipation relief.
You’ve probably also seen the word prebiotic thrown around lately. Prebiotics are soluble dietary fibers that help feed the health bacteria in your gut. “All prebiotics are fiber, but not all fibers are prebiotic,” says Brynna Connor, MD, a board-certified family medicine physician at NorthWestPharmacy.com. “These soluble dietary fibers pass through the intestinal tract until they reach the lower digestive tract, primarily in the colon, where they feed, stimulate, and promote the growth of good bacteria.”
While supplements can be a great way to ensure you’re meeting your daily minimum, a fiber-rich diet of whole grains, fruits, vegetables, and legumes, ensures you’re getting a healthy balance of both types of fiber. One of the easiest ways to organically increase these fiber-rich whole foods in your diet is to make small swaps, like replacing processed snacks with fresh fruits or veggies, adding in whole grains like quinoa or brown rice instead of simple carbs, or incorporating superfoods like chia seeds. You could also try adding leaf greens to smoothies or sandwiches to sneak in more veggies.
What are the benefits of a fiber supplement?
Fiber supplements are perhaps most associated with their ability to support healthy digestion—and they certainly live up to their reputation. “Fiber supplements can improve digestive health by promoting regular bowel movements and reducing constipation,” says Ella Davar, RD, founder of Gut-Brain Method.
But the benefits of fiber span far beyond reliable digestion. For one, fiber is key to a healthy gut microbiome. “We've all heard about the benefits of gut health and taking probiotics, which is great, but you also need fiber to help the good bacteria in your gut do its job,” says Kristen Reed, RN, a board-certified registered nurse and certified health coach. By extension, because of its importance in fostering a healthy gut microbiome, fiber may help support healthy immune system function and mental health.
What’s more, taking fiber can also have a positive impact on cholesterol levels—soluble fiber, specifically, binds to LDL (aka “bad”) cholesterol in the intestines, and prevents it from getting absorbed into the body, explains Ruvini Wijetilaka, MD, a provider at Parsley Health. It can also help regulate blood sugar levels, and support healthy weight management as it promotes feelings of fullness.
Should you take a fiber supplement?
As with all supplements—a fiber supplement is most helpful in filling a nutritional gap. According to the USDA, the majority of US adults fall short of the daily recommended fiber intake of 28 grams for women and 34 grams for men. So if you’re not getting enough fiber in your diet from grains and veggies alone, then a supplement may be helpful in making up the difference.
While fiber supplements can support digestion, they also may not be right for everyone: Individuals with certain digestive disorders (such as diverticulitis) should avoid these supplements. In general, it’s a good idea to speak with your healthcare provider before adding any kind of supplement to your routine.
What to look for in a fiber supplement
As you’re shopping for fiber supplements, you’ll see many different sources—psyllium husk, methylcellulose, wheat dextrin, and acacia gum, just to name a few. And everyone’s gut microbiome is different, so there’s no magic formula that works best for all, says Luk. It’s definitely worth chatting with your doctor first about what might be best for you, and sometimes, finding the right supplement takes a bit of trial and error.
Since supplements like fiber aren’t regulated by the FDA, you’ll want to stick with products from a reputable brand and purchase them from a trusted vendor. “Opt for products tested by third-party organizations (like National Sanitation Foundation or NSF) to ensure the quality and accuracy of what the supplement is marketing,” says Bree Phillips, a registered dietitian at UCSF Health. And avoid any products with artificial sweeteners, flavors, colors, and excess added sugars—as those can irritate the gut and even exacerbate digestive issues for sensitive individuals.
Is it good to take a fiber supplement daily?
In general, taking a fiber supplement every day can be perfectly healthy, just be sure to chat with your doctor before adding any supplement to your regular routine. What’s more, “too much too soon can be hard for the body to handle, so I recommend increasing intake gradually,” says Maggie Moon, MS, RDN, a registered dietitian based in Los Angeles.
And don’t forget to up your water intake when you start adding more fiber to your diet. Otherwise, you may experience unwanted symptoms like bloating, cramping, and flatulence, says Phillips.
- Angel Luj, RD, a registered dietitian in Richmond, British Columbia
- Brynna Connor, MD, a board-certified family medicine physician at NorthWestPharmacy.com
- Ella Davar, RD, founder of Gut-Brain Method
- Kristen Reed, RN, a board-certified registered nurse and certified health coach
- Ruvini Wijetilaka, MD, a provider at Parsley Health
- Maggie Moon, MS, RDN, a registered dietitian in Los Angeles
Best Overall: Thorne FiberMend
Original image by Glamour reviewer Hannah Singleton drinking Thorne FiberMend
- Fiber per serving: 7 grams
- Serving size: 1 scoop (11 grams)
- Servings per container: 30
- Fiber type: Soluble (partially hydrolyzed guar gum, apple pectin), insoluble (rice bran)
- Sugar per serving: >1 gram
- Pros: Prebiotic fiber blend for settling the stomach and improving constipation; subtle flavor
- Cons: Relatively pricey
Thorne FiberMend is the fiber MVP that registered dietitians can’t stop recommending because of the brand’s high quality standards and “credibility from collaborations with reputable organizations, like Mayo Clinic and US Olympic teams,” says Luk. And this one has “been clinically shown to help improve diarrhea and constipation, making it a reliable choice for supporting regular bowel movements,” says Phillips. With mostly soluble fiber, it’s a reliable option for satiety and overall gut health. “When I tested it, I found it completely flavorless in water—and totally unnoticeable when added to my morning shake or yogurt,” says Glamour contributor Hannah Singleton.
Best-Tasting Fiber Supplement: BelliWelli Daily Fiber Supplement
Original image by Glamour reviewer Hannah Singleton drinking BelliWelli Daily Fiber Supplement
BelliWelli Daily Fiber Supplement
- Fiber per serving: 4 grams
- Serving size: 1 scoop (11 grams)
- Servings per container: 16
- Fiber type: Soluble (acacia fiber)
- Sugar per serving: 2 gram
- Pros: Features electrolytes, collagen, and probiotics; good taste; also comes in single-serve pouches for travel
- Cons: Some flavors don’t dissolve super well.
This fiber supplement features two grams of collagen to keep your skin, hair, and nails happy and one billion CFU probiotics to enhance your gut health. “I adore BelliWelli’s fiber supplement! It not only keeps me regular but also feels like a luxurious treat that I know is nurturing my body,” says Glamour tester Rachel Hirsch, founder of Empowered Yoga. “Plus, it has more than just fiber—it contains collagen, probiotics, and electrolytes, so I feel like I’m giving myself a comprehensive daily boost for my overall well-being.”
Best for Travel: Benefiber Prebiotic Fiber Powder
Original image by Glamour commerce director Brie Schwartz drinking Benefiber Prebiotic Fiber Powder
Benefiber Prebiotic Fiber Powder
- Fiber per serving: 3 grams
- Serving size: 2 teaspoons
- Servings per container: 62 or 125
- Fiber type: Soluble (wheat dextrin)
- Sugar per serving: >1 gram
- Pros: More cost-effective than other option; travel-friendly; flavorless so easy to add to water
- Cons: Relatively low fiber per serving; should not be used by those with celiac disease
Benefiber is one of the most popular fiber supplements, along with Metamucil, and this version comes in ultraconvenient individual packets so you can mix it into cold drinks, hot bevs, and soft food. Basically, it’s perfect for people who are on the go, traveling, or running errands. “I've tried many fiber supplements so I can know what's out there, but honestly, one I always come back to and that my clients love is the Benefiber Prebiotic Fiber powder,” says Jessica Cording, MS, RD, a registered dietician and health coach. “It dissolves really well and I appreciate that it doesn't have any sugar.” It’s unflavored and pretty simple, but that’s why it’s the perfect thing to throw in your purse—you can just add it to water and sip away. If you prefer something flavored, it also comes in a strawberry lemonade version which Glamour's commerce director, Brie Schwartz uses.
“I started taking this a few weeks before I had a big trip planned, and not to be TMI, but I do find it effective. It (relatively quickly) works to eliminate bloat, and so on. The flavor can be a bit overpowering if you don't add enough water, and there's always one last small clump at the bottom of the glass, but I find the taste pleasant, the color is delightful, and I make sure I always pack a few when I travel to help eliminate the dreaded vacation tummy,” says Schwartz.
Best Natural Fiber Source: Gainful Fiber
Original image by Glamour reviewer Hannah Singleton drinking Gainful Fiber
- Fiber per serving: 5 grams
- Serving size: 1 scoop (10 grams)
- Servings per container: 14
- Fiber type: Soluble and insoluble (oat bran)
- Sugar per serving: >1 gram
- Pros: Natural fiber sourced from real ingredients; includes both soluble and insoluble fiber for joint benefits
- Cons: Not many servings in the container—you don’t get as much bang for your buck; contains gluten
If you’re not a fan of ingredient labels full of unpronounceable stuff, Gainful’s oat bran supplement is refreshingly simple. Oat bran is basically the outer layer of the edible part of oats, and is “naturally a part of oat groats, steel-cut oatmeal, and processed oatmeal,” says Luk. You probably already eat something like it, so it feels a lot more “natural” than other options like guar gum. It’s high in soluble fiber, meaning it can help with cholesterol, blood sugar, and keeping your digestion in check. “It’s also associated with lowering blood pressure,” she adds.
“I used this supplement for a few months, and it dissolved better than any other fiber supplements I tried. However, I liked it best when I added it to my daily protein shake, which includes protein powder, oat milk, fiber, collagen, and sometimes yogurt or a banana. It doesn’t change the flavor dramatically—just makes it slightly earthier—but still totally smooth,” says Singleton.
Best for Cholesterol: Metamucil 4-in-1 Fiber Supplement
Metamucil 4-in-1 Fiber Supplement
- Fiber per serving: 6 g dietary fiber, 5 g soluble fiber
- Serving size: One tablespoon
- Servings per container:
- Fiber type: Soluble (psyllium husk)
- Form: Powder
- Sugar per serving: 8 g
- Pros: Made with real sugar, psyllium husk
- Cons: Can be difficult to take
Metamucil is often considered the gold standard according to doctors—and as far as fiber supplements go, it’s perhaps the biggest household name. “I started taking Metamucil a few months ago at the recommendation of my gastroenterologist and I really like it,” says Glamour contributor Jessie Van Amburg. “I drink the one with real sugar (bc sugar alcohols upset my stomach) and find the flavor mild and pleasant like watered down orange juice. Because you take this fiber with a big glass of water, I find it doesn’t bloat me up and it…definitely works well to keep things moving.” She says the only downside is if you’re a slow sipper, the Metamucil starts to turn into a gel that makes it more challenging to drink, unless you add more water and stir away.
Best Organic: Organic India Psyllium Herbal Powder
Organic India Psyllium Herbal Powder
- Fiber per serving: 5 grams
- Serving size: 1 tablespoon
- Servings per container: 68
- Fiber type: Soluble (psyllium husk)
- Sugar per serving: None
- Pros: Single source of fiber so you know what you’re getting; free of any additives, including sugar; organic
- Cons: Thickens rather quickly; tastes a bit like sawdust
If you’re after the purest form of fiber, psyllium fiber is where it’s at. “I take psyllium husk every morning in my smoothie, mixing it really well so that it goes down and doesn't clump,” says Amie Alexander, a registered dietitian at Nutri Peak. What’s more, “psyllium is a well-researched source of fiber that can help with cholesterol lowering, blood sugar regulation, and feelings of fullness,” says Moon.
Of all the psyllium husk supplements she tried (read: many), Glamour contributor Kristine Thomason favored Organic India’s herbal powder. “I love that it literally has one ingredient: organic psyllium husk, and it’s both fair trade-certified and sustainably sourced,” she says. “Admittedly, you need to chug this powder pretty fast otherwise it becomes difficult to sip, but I appreciate the simple, no-fuss product.”
Best Capsules: Yerba Prima Psyllium Husks Veg Caps
Yerba Prima Psyllium Husks Veg Caps
- Fiber per serving: 2.2 g
- Serving size: 4 capsules
- Servings per container: 100
- Fiber type: Soluble (psyllium husk)
- Sugar per serving: None
- Pros: Single source of fiber; free of any additives; vegan; easy-to-take
- Cons: Earthy taste, 4 capsules per serving
When it comes to fiber supplements, this Yerba Prima psyllium husk capsule can be a much easier, well, pill to swallow. The vegan-friendly supplement comes highly recommended by both Davar and Moon, due to its simple ingredient list (just psyllium husk, nothing else). “After my doctor recommended I incorporate fiber supplements into my daily diet, I’ve been diligent about taking psyllium husk every morning. On the days I don’t feel like blending my fiber in a glass of water, I’ll reach for these easy-to-take capsules instead,” says Thomason.
Best Acacia Powder: NOW Supplements Acacia Pure Powder
Now Supplements Acacia Pure Powder
- Fiber per serving: 6.5 g
- Serving size: 1 tablespoon
- Servings per container: 52
- Fiber type: Soluble (acacia powder)
- Sugar per serving: None
- Pros: Single source of fiber; free of any additives; easy-to-mix
- Cons: May not dissolve completely
Acacia fiber is another excellent form of soluble fiber—especially a simple, straightforward formula like you’ll find in this powder. Reed personally recommends this option from Now, as she appreciates the brand’s quality standards and accessible pricepoint. “I add the acacia fiber to my smoothies, or stir it into anything like chia pudding, faux oatmeal, etc,” she says. “After using a fiber supplement every day—along with following my healthy plate template-which means making sure every meal includes protein, fiber, fats, and greens—I've noticed more energy thanks to stabilized blood sugar, regular bowel movements, and less bloating and GI upset.”
Best Gummy: New Chapter Organic Fiber Gummies
New Chapter Organic Fiber Gummies
- Fiber per serving: 4 grams
- Serving size: 2 gummies
- Servings per container: 30
- Fiber type: Soluble (organic blue agave inulin)
- Sugar per serving: >1 gram
- Pros: Easy to take, compared to powders; fruity flavor with no added sugar
- Cons: Some reviewers noted increased bloating.
Who says fiber has to taste like cardboard? Maggie Michalczyk, a registered dietitian in Chicago, recommends New Chapter’s organic gummies because they pack in 8 grams of prebiotic fiber with no added sugar and, somehow, actually taste great. “I like that they provide holistic microbiome support, which is important when it comes to promoting regularity and preventing bloating,” she says. (This means the prebiotics help nourish the beneficial bacteria in your gut.) They’re gluten-free, USDA-certified organic, vegan, and non-GMO verified, making them an easy fit for just about any diet.
Best for Bloating: Tomorrow’s Nutrition SunFiber
Tomorrow’s Nutrition SunFiber
- Fiber per serving: 6 grams
- Serving size: 1 scoop (7 grams)
- Servings per container: 30
- Fiber type: Soluble (guar fiber)
- Sugar per serving: >1 gram
- Pros: Nearly invisible flavor and texture to add to any food or drink; doesn’t cause bloating or cramping
- Cons: Some reviewers found it didn’t provide any benefits (but not every fiber fits every body)
If you want a fiber supplement that actually dissolves without turning into gooey sludge, Dr. Connor recommends Tomorrow’s Nutrition SunFiber. You can add it to just about anything—coffee, water, smoothies—and barely even know it’s there because it’s virtually tasteless. Plus, it’s gentle on the digestive system, so you won’t feel like you’re fighting off bloating or cramping.
Best for Weight Loss: Pure Encapsulations PureLean Fiber
Pure Encapsulations PureLean Fiber
- Fiber per serving: 6 grams
- Serving size: 2 scoops (14.4 grams)
- Servings per container: 24
- Fiber type: Soluble (partially hydrolyzed guar gum, apple pectin) and insoluble (cellulose, flax seed)
- Sugar per serving: >1 gram
- Pros: Combo of soluble and insoluble fiber; clean ingredients; added electrolytes
- Cons: Serving size is larger, so it’s not as discreet as other products when you add to drinks or smoothies, expensive
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