The best fiber supplement

Ana Sanchez

Fiber supplements may cause bloating or gas when you first start taking them. Give your body time to adjust, as most of these symptoms go away as your body gets used to the extra fiber.

Dietary fiber is plant-derived roughage that is essential to good digestion. Many people's diets are sorely lacking fiber, which leads to constipation and other bowel problems. Fiber is also an important component of weight loss; it helps you feel full longer.

If you need fiber in your diet but you're not big on eating leafy greens, whole grains, or fruits, you're in luck -- fiber supplements can make up the deficiency. Our buying guide will help you pick one that's both palatable and right for your health needs. Our top pick is from Metamucil, a tried-and-true fiber powder that helps keep you regular.

Considerations when choosing fiber supplements

Types of fiber

Soluble fiber is the fiber found in oatmeal, apples, carrots, flaxseed, and oranges. It absorbs water and slows down food in the digestive tract. If you suffer from IBS or diarrhea, soluble fiber can help solidify watery stools. It also may help regulate cholesterol and blood sugar.

Insoluble fiber is the fiber found in leafy greens, wheat bran, nuts, and seeds. It doesn't absorb water, so it speeds up the movement of food through the digestive tract. Insoluble fiber is good for constipation. It also helps maintain a healthy pH balance in your gut.


Fiber supplements are derived from different sources, each with unique benefits and drawbacks.

Psyllium is sourced from seed husks. It gives you a combination of insoluble and soluble fiber, which means you feel fuller longer and experience increased regularity. However, it can cause bloating and gas.
Methylcellulose comes from plant cellulose. It's a soluble fiber that's less likely to make you bloated or gassy than psyllium. It typically comes in a powder form that has to be dissolved in cold liquids.
Inulin is a soluble fiber usually sourced from chicory root. It has the extra benefit of containing prebiotics that feed good gut bacteria. The drawback is that inulin can also cause gas. 
Wheat dextrin is derived from wheat, but interestingly, often meets gluten-free standards. It's a soluble fiber sold in powder form that can be dissolved in hot or cold beverages.


Sweeteners and flavors are added to some formulas to remedy texture and taste issues sometimes present in fiber supplements.

Sugar is commonly added to fiber powders -- up to 10 grams per dose. If you're diabetic or watching your sugar intake, check labels to see how much sugar is added. Opt for one with a natural, non-sugar sweetener like stevia.
Artificial sweeteners are an alternative to sugar to help mask the taste of fiber powders. If you're worried about the health risks involved with artificial sweeteners, flavors, or colorings, you can find additive-free forms of fiber.


Powders are popular because they generally dissolve into liquids or soft foods, making them easy to take. However, you taste this form of fiber more than if you swallow pills.
Capsule forms of fiber supplements often require more than one pill per dose because fiber is bulky. If you have trouble swallowing pills, especially large ones, opt for a powder. 

Fiber supplement prices

Fiber supplements range in price from $7 to $30 per container.


Q. How much fiber should I take per day?
The recommended daily allowance (RDA) is 38 grams per day for men and 25 grams per day for women. Most people only ingest half of the recommended amount through their diets.

Q. Should I take a fiber supplement with food?
You can take a fiber supplement with food or on an empty stomach. It's more important that you drink plenty of fluids when adding more fiber to your diet to prevent dehydration.

Fiber supplements we recommend

Best of the best: Metamucil Daily Fiber Supplement

Our take: A popular powder that provides soluble and insoluble fiber from psyllium.

What we like: Subtle orange flavor that's sugar-free. Helps keep you full. Heart and gut friendly formula.

What we dislike: Contains artificial flavors and sweeteners.

Best bang for your buck: Optimum Nutrition Fitness Fiber

Our take: Budget-priced fiber powder with a focus on athletic performance.

What we like: A complement to exercise regimens for weight loss. Only 10 calories a serving.

What we dislike: Taste takes some getting used to.

Choice 3: Garden of Life Raw Organic Superfood Fiber Powder

Our take: A raw fiber powder with no artificial additives and bonus ingredients.

What we like: Contains 15 organic superfoods that aid digestion. Vegan. Also contains omega-3s, seven grams of protein, and probiotics.

What we dislike: Though probably the healthiest, not the best-tasting fiber powder around.

Ana Sanchez is a writer for BestReviews. BestReviews is a product review company with a singular mission: to help simplify your purchasing decisions and save you time and money. BestReviews never accepts free products from manufacturers and purchases every product it reviews with its own funds.

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