Fiber (psyllium, inulin, glucomannan) supplements, compared
15 products we’ve reviewed list fiber (psyllium, inulin, glucomannan) as a key ingredient. Here’s what it does, what the research uses — and how much each product actually contains.
What it is
Soluble fibers absorb water, add bulk and — in the case of prebiotics like inulin — feed gut bacteria.
What the research uses
The recommendation for adults is 21–38 g of fiber a day from all sources — most Americans get about 16 g. Increase slowly and drink plenty of water to avoid bloating.
Educational information, not medical advice. Talk to a healthcare professional before starting a supplement, especially if you are pregnant, nursing or take medication.
Every product, dose by dose
| Product | Fiber (psyllium, inulin, glucomannan) per serving | Form | Score |
|---|---|---|---|
 | 3 g dietary fiber (2 g soluble) per rounded teaspoonPsyllium husk fiber | Powder | 8.3 |
 Third-party tested | 11 gDietary fiber | Powder | 8.1 |
 cGMP facility | 200 mgInulin (chicory root extract) | Capsule | 8.0 |
 USDA OrganicKosher | 7 g total dietary fiberOrganic agave inulin and acacia fiber | Powder | 7.5 |
 Third-party testedcGMP facility | 6 g fiberFiber & Probiotics Blend (flax, acacia gum, chia, soluble corn fiber, chicory root, L. rhamnosus Lrha51, L. acidophilus UALa-01) | Powder | 7.2 |
 USDA OrganicKosher | Not disclosedOrgain Organic Fruit & Vegetable Blend (apple fiber, acai, beet, kale, raspberry, spinach, tomato, banana, blueberry, carrot) | Ready to drink | 7.1 |
 cGMP facilityKosherHalal | 1,725 mg per serving (575 mg per capsule)Glucomannan (from konjac root, Amorphophallus konjac) | Capsule | 6.9 |
 KoshercGMP facility | 620 mgFiber Blend (organic flax seed, apple pectin) | Powder | 6.8 |
 Third-party testedcGMP facility | 6 gDietary fiber (tapioca fiber, organic inulin) | Gummy | 6.8 |
 Non-GMO Project VerifiedKosher | 3 g fiberSoluble fiber | Ready to drink | 6.7 |
 Third-party testedcGMP facility | 1.606 gFiber Blend (chicory root fructo-oligosaccharides, organic flaxseed, apple fruit powder)648 mgPre and Probiotic Blend (blue agave inulin, B. bifidum, L. rhamnosus, L. acidophilus) | Powder | 6.1 |
 Third-party testedcGMP facility | 3 gDietary fiber | Powder | 5.9 |
 USDA Organic | Not disclosedOrganic prebiotic blend (acacia, inulin, tapioca fiber) | Powder | 5.7 |
 USDA OrganicThird-party testedcGMP facility | Not disclosedOrganic Antioxidant Powder Blend (blueberry, cranberry, raspberry, strawberry, beet root) with organic inulin2 gDietary fiber | Powder | 5.4 |
 | 211 mgChicory inulin | Capsule | 4.9 |
Amounts are per serving as printed on each label. “Not disclosed” usually means the ingredient sits inside a proprietary blend.
Questions people ask
How much fiber (psyllium, inulin, glucomannan) do studies use?
The recommendation for adults is 21–38 g of fiber a day from all sources — most Americans get about 16 g. Increase slowly and drink plenty of water to avoid bloating.
Which fiber (psyllium, inulin, glucomannan) supplement scores highest?
In our reviews, Metamucil 4-in-1 Psyllium Fiber Powder, Sugar-Free scores highest at 8.3/10, followed by Huel Black Edition (8.1) and Culturelle Digestive Daily Probiotic Capsules (8.0). Scores weigh efficacy, quality, value, experience and transparency — not just the dose.
How much fiber (psyllium, inulin, glucomannan) is in these products?
It varies by product and serving size — for example Metamucil 4-in-1 Psyllium Fiber Powder, Sugar-Free (3 g dietary fiber (2 g soluble) per rounded teaspoon), Huel Black Edition (11 g), Culturelle Digestive Daily Probiotic Capsules (200 mg). The table above lists the amount per serving for every product we've reviewed.