5 Best Soluble and Insoluble Fiber Supplements (2026)

Momentous Fiber+ stands out for taking a comprehensive, performance-focused approach to fiber. Instead of relying on a single source like psyllium husk, it combines three types: soluble fiber (psyllium), insoluble fiber (rice bran hull), and resistant starch from Solnul® potato starch. That 3-in-1 formula supports digestive regularity, smoother transit, and prebiotic activity in one daily serving, a more complete strategy than many competitors that offer just one fiber type.

The inclusion of Solnul® resistant potato starch is particularly notable. This branded ingredient has been clinically studied at 3.5 grams per day to support beneficial gut bacteria such as Bifidobacterium and Akkermansia. For those focused on microbiome health(not just symptoms like regularity, bowel movements, or constipation) that distinction matters.

Developed in partnership with Arnold Schwarzenegger and experts at The Pump Club, the formula reflects a performance mindset. NSF Certified for Sport status adds another layer of trust, verifying label accuracy and screening for contaminants and banned substances, which is valuable reassurance for athletes and anyone who’s serious about what they put into their body.

At $39.95 for 30 servings (6g fiber per serving), it is not the lowest-cost option. Those prioritizing price alone may find cheaper psyllium-only products. However, the vegan, gluten-free, non-GMO formulation, two flavor options (including a well-reviewed Pure Cinnamon made with real cinnamon bark), and strong subscription discount help justify the premium.

For anyone seeking a well-rounded, microbiome-supportive fiber supplement designed with quality standards in mind, this is a product worth exploring further.

Key Things to Know About This Product

• Third-Party Tested: No 

• Money-Back Guarantee: Yes

• Gluten Free: Yes

• GMO Free: Yes

• Vegan: Yes

Product Details:

• Price: $34.95

• Number of Servings: 180

• Amount of fiber per serving: 3g dietary fiber from psyllium husk (of which 2g soluble fiber)

• Serving Size: 1 rounded teaspoon (5.8g)

• Subscription: N/A

• Free shipping: Online distributors include Amazon & Target 

• Flavors: Orange, berry, lemonade, unflavored

Pros:

• Cost effective ($0.19/serving)

• Available online and in stores

Cons:

• Only contains 3g fiber per serving

• Only provides soluble and insoluble fiber

• Contains artificial flavors (aspartame and yellow 6)

• No third-party testing

Metamucil 4-in-1 Fiber is one of the most recognizable names in the fiber category, and its wide retail availability through outlets like Amazon and Target makes it easy to find. At roughly $0.19 per serving, it’s undeniably cost-effective.

However, beyond price and convenience, the formula is fairly basic. Each serving provides just 3 grams of dietary fiber, primarily from psyllium husk (2 grams soluble fiber). For anyone trying to meaningfully increase total daily intake toward the recommended 25–38 grams, that relatively low dose may require multiple servings per day.

It also relies solely on psyllium husk, meaning it offers soluble and some insoluble fiber, but no resistant starch or dedicated prebiotic ingredient. Those specifically seeking microbiome support beyond stool regularity may find this limiting compared to more comprehensive blends.

Another consideration is quality assurance. The product is not third-party tested, which means there’s no independent verification of purity or label accuracy. Additionally, several flavored versions contain artificial sweeteners (aspartame) and synthetic dyes (Yellow 6), ingredients that many consumers prefer to avoid.

Overall, while affordable and accessible, this product prioritizes convenience over formulation depth and quality transparency.

Key Things to Know About This Product

• Third-Party Tested: No

• Money-Back Guarantee: Yes

• Gluten Free: Yes*

• GMO Free: Yes

• Vegan: Yes

Product Details:

• Price: $19.99

• Number of Servings: 62

• Amount of fiber per serving: 3g

• Serving Size: 4 teaspoons (8g)

• Subscription: N/A

• Free shipping: Online distributors include Walmart and Target 

• Flavors: Unflavored

Pros:

• Cost effective ($0.32/serving)

• Unflavored (no artificial flavors)

• Sugar free

• Widely available online and in-store

Cons:

• Not third-party tested

• Only contains one type of fiber

• Only contains 3g fiber per serving

• Sourced from wheat dextrin

Benefiber Prebiotic Fiber Powder is positioned as a simple, no-frills way to add fiber to daily routines. It’s unflavored, sugar-free, and dissolves easily into coffee, water, or soft foods without noticeably changing texture, which is a practical advantage for those who dislike gritty or flavored powders. At $19.99 for 62 servings (about $0.32 per serving), it’s also relatively affordable and widely available through retailers like Walmart and Target.

That said, the formula is limited. Each serving provides just 3 grams of fiber sourced exclusively from wheat dextrin. While marketed as “prebiotic,” it contains only this single fiber type; there’s no blend of soluble, insoluble, or resistant starch to provide broader digestive support. Anyone aiming to significantly increase total daily fiber intake may need multiple servings to make a meaningful impact.

It is labeled gluten-free, though it is derived from wheat, so it is not recommended for celiacs or anyone highly sensitive to gluten. It’s also not third-party tested, meaning there is no independent verification of purity or label accuracy.

Overall, this is a convenient, entry-level fiber supplement best suited for those seeking a mild, easily mixed option rather than a comprehensive gut health formula.

Key Things to Know About This Product

• Third-Party Tested: Yes, certified gluten free

• Money-Back Guarantee: Yes

• Gluten Free: Yes

• GMO Free: Yes

• Vegan: Yes

Product Details:

• Price: $53

• Number of Servings: 24

• Amount of fiber per serving: 6g

• Serving Size: 2 scoops (14.4g)

• Subscription: Yes - subscribe and save 10%

• Free shipping: Yes

• Flavors: Unflavored

Pros:

• Contains soluble and insoluble fiber

• Certified gluten free

• Vegan and GMO free

• 6g fiber per serving

• Free shipping

Cons:

• Cost ($2.20/serving)

• Not NSF or Informed Sport certified

• Contains a lot of other ingredients: sodium, protein, magnesium citrate

• Contains a proprietary fiber blend

Pure Encapsulations PureLean Fiber delivers 6 grams of fiber per serving and includes both soluble and insoluble fiber, which is a meaningful advantage over single-source products. That dual approach can support both stool regularity (via insoluble fiber) and metabolic or cholesterol benefits (via soluble fiber). The formula is also vegan, non-GMO, and certified gluten-free, which may appeal to anyone with dietary restrictions.

However, several trade-offs are worth noting. At $53 for just 24 servings, the cost comes out to roughly $2.20 per serving, making it one of the more expensive options in this category. While it carries gluten-free certification, it does not undergo broader third-party testing such as NSF Certified for Sport or Informed Sport, meaning there’s no independent verification of ingredient purity or label accuracy beyond gluten status.

Some of the fiber content is delivered through a proprietary blend, so the exact breakdown of each fiber type is not disclosed. For consumers who prefer full transparency around dosing, that lack of specificity may be a drawback. The formula also contains additional ingredients such as magnesium citrate, sodium, protein, and sugar alcohols, which may be a deterrent for those seeking a straightforward fiber supplement.

Overall, this product offers solid fiber diversity but at a premium price with limited transparency.

Key Things to Know About This Product

• Third-Party Tested: Yes, NSF Contents Certified

• Money-Back Guarantee: Yes

• Gluten Free: Yes

• GMO Free: Not stated

• Vegan: Not stated

Product Details:

• Price: $45

• Number of Servings: 30

• Amount of fiber per serving: 7g

• Serving Size: 1 scoop (11g)

• Subscription: Yes - subscribe and save 10%

• Free shipping: Yes

• Flavors: Unflavored

Pros:

• NSF Contents Certified

• Contains 7g dietary fiber per serving

• Contains a mix of soluble and some insoluble fiber

• Free shipping

Cons:

• Price ($1.50/serving)

Thorne FiberMend delivers 7 grams of dietary fiber per serving, which is a meaningful dose compared to many mainstream fiber powders. The formula includes a blend of primarily soluble fiber (such as partially hydrolyzed guar gum) along with some insoluble fiber, supporting both stool consistency and overall gut function. The unflavored powder mixes easily into water, coffee, or smoothies, making it simple to incorporate into a daily routine.

One advantage is its NSF Contents Certified status. This certification verifies that the ingredients listed on the label are present in the stated amounts and that the product meets certain contaminant standards. However, it’s important to note that NSF Contents Certified is not the same as NSF Certified for Sport. It does not include testing for banned substances, which may matter to competitive athletes or those seeking the highest level of third-party verification.

At $45 for 30 servings (about $1.50 per serving), it sits at a premium price point. GMO-free and vegan status are not explicitly stated, which may require additional verification for anyone with strict dietary preferences.