Best Fiber Supplement in Canada (2026): Ranked by Cost Per Gram of Fiber
Informational summary, not medical advice. Prices are live Amazon.ca prices, verified September 20, 2026; they change.
The best fiber supplement is not a brand but a type bought cheaply: psyllium husk, at the 7 g of soluble fiber a day behind its FDA heart claim.Psyllium has the best evidence (the only fiber with an FDA heart claim, plus support for constipation and IBS), and bought as plain husk powder it's also the cheapest per gram of any well-evidenced fiber (only wheat dextrin, with weaker evidence, runs cheaper). Top pick: NOW Psyllium Husk Powder, Organic (12 oz). Pick psyllium capsules instead if you don't want to mix a powder, or inulin only to feed gut bacteria.
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| Item | Value |
|---|---|
| Benefiber | $0.073 |
| NOW Foods | $0.081 |
| NOW Foods | $0.087 |
| Metamucil | $0.103 |
| NOW Foods | $0.510 |
The picks
NOW Psyllium Husk Powder, Organic (12 oz)
Plain organic psyllium husk: 7 g fiber (6 g soluble) per serving, just under the FDA 7 g/day soluble-fiber target in a single serving, and the cheapest per gram of any well-evidenced fiber in this list (only wheat dextrin, with weaker evidence, runs cheaper). The most evidence, the least fuss, the best price. Start here.
Check price on Amazon.ca →NOW Supplements Psyllium Husk Caps 500 mg
A single ingredient, psyllium husk, with no flavoring or sweeteners, no scooping or mixing. Capsules carry less fiber per dollar than the powder, so it costs noticeably more per gram, the pick if you want psyllium and nothing else, in capsule form.
Check price on Amazon.ca →The full ranking
Every product here, ranked by cost per gram of fiber. Remember the type column matters as much as the price: inulin is cheap but it's a prebiotic, not a bulking fiber, and wheat dextrin is a weak laxative, see fiber types compared.
| Product | Type | Fiber/serving | Price | Cost/g fiber | |
|---|---|---|---|---|---|
| Benefiber: Prebiotic Fiber Powder (wheat dextrin) | Wheat dextrin | 3 g | $27.18 | $0.073 | Price → |
| NOW Foods: NOW Psyllium Husk Powder, Organic (12 oz) | Psyllium | 7 g | $21.30 | $0.081 | Price → |
| NOW Foods: NOW Supplements Inulin Prebiotic Pure Powder, Certified Organic | Inulin (prebiotic) | 3 g | $18.44 | $0.087 | Price → |
| Metamucil: 4-in-1 Psyllium, Sugar-Free (72 servings) | Psyllium | 3.4 g | $24.97 | $0.103 | Price → |
| NOW Foods: NOW Supplements Psyllium Husk Caps 500 mg | Psyllium | 1 g | $15.99 | $0.510 | Price → |
How we ranked
We don't rank by tub size or brand recognition. Two things decide it:
- Fiber type & evidence first. A cheap fiber that doesn't do the job isn't a bargain. Psyllium leads because it has the evidence (FDA cholesterol claim; RCTs for constipation and IBS) and does all three fiber jobs, gels, resists fermentation, and bulks. Here's the breakdown.
- Then cost per gram of fiber. The honest value metric isn't price per tub, it's price ÷ grams of actual fiber, using each product's label serving. That's what the table above shows.
What we deliberately ignore: "prebiotic," "gut health," and "GLP-1 friendly" front-label marketing that isn't backed by the fiber type inside, and big milligram numbers that turn out to be small once you read the serving size.
Method: the fiber products in our US catalog were checked one by one against the NSF/ANSI 173 registry (3,053 listings), the USP Verified list (159 products) and the Informed Sport database (2,105 products) in our 2026-08-25 snapshots, and each US brand site was read for a lot certificate on 2026-09-19. That brand-site check was not run on the Canadian substitutes below; they were built from their Amazon.ca listings only, and none of the 5 products carried in this Canadian edition is listed in those registries. The full ladder is on the third-party-tested fiber page; cost per gram uses the fiber grams on each Supplement Facts panel, not the scoop weight.
Price check · Fiber
What Fiber actually costs across the brands we track
What you pay. The 5 Fiber products here run $0.22 to $0.57 a day across 3 brands, a 2.6× gap. of the 5 state some certification on the listing itself, which is a different and weaker claim than appearing in the registry above: one is what the Fiber label says, the other is what a certifier confirms.
Method: the 5 Fiber products in our catalogue, each priced at its own labelled serving rather than by pack size, across 3 brands. How we price.
Buying fiber on Amazon.ca: the exact listings we track
These are the 5Amazon.ca listings behind this page, identified by ASIN so you land on the container we priced rather than a lookalike. Prices are the current buy-box price, verified 2026-09-20, divided by the label serving count. Cheapest per day: Benefiber Prebiotic Fiber Powder at $0.22. None of the 5 is in a certification registry in our snapshot.
| Listing | ASIN | Price | Cost per day | Verification | Buy |
|---|---|---|---|---|---|
| Benefiber Prebiotic Fiber Powder | B0F9YZ98B4 | $27.18 | $0.22 | not checked | Check price → |
| NOW Supplements Inulin Prebiotic Pure Powder, Certified Organic | B01IRIPVR8 | $18.44 | $0.26 | not checked | Check price → |
| Metamucil 4-in-1 Psyllium, Sugar-Free | B0B352GCKT | $24.97 | $0.35 | not checked | Check price → |
| NOW Supplements Psyllium Husk Caps 500 mg | B003FG88QO | $15.99 | $0.51 | not checked | Check price → |
| NOW Psyllium Husk Powder, Organic | B002N0OFEM | $21.30 | $0.57 | not checked | Check price → |
Three checks on the Amazon.ca listing itself
- Who is selling it. The “Sold by” line should read the brand, Amazon, or the brand’s named distributor. Amazon commingles inventory for many ASINs, so a third-party seller on a supplement listing is the one place a counterfeit or expired unit can enter.
- The lot and the expiry on arrival. For a product with a certificate lookup or a registry listing, the lot number on the container is what you check, not the listing. A lot older than the certificate date, or an expiry inside a year, is a reason to return it.
- The serving count, not the piece count. The per-day figures above use the label’s serving; a listing that says “240 count” at two pieces a serving is 120 days, and Amazon’s own “price per count” ignores that.
Product links go to Amazon and we may earn a commission if you buy. It never changes which product we pick or what we say about it. How we choose.
Cost per gram of fiber, product by product
Each line is the arithmetic behind the ranking: the container price divided by the fiber grams it holds (label fiber per serving times servings), then what it takes to reach 7 g of fiber a day. Cheapest first.
- Benefiber Prebiotic Fiber Powder (wheat dextrin) (Wheat dextrin): 3 g of fiber per 1 dose, 125 servings at $27.18, so $0.073 per gram; 7 g a day takes 3servings and costs about $0.51, or $187 a year.
- NOW Psyllium Husk Powder, Organic (12 oz) (Psyllium): 7 g of fiber per 1 tbsp (9 g), 38 servings at $21.30, so $0.081 per gram; 7 g a day takes 1serving and costs about $0.57, or $208 a year.
- NOW Supplements Inulin Prebiotic Pure Powder, Certified Organic (Inulin (prebiotic)): 3 g of fiber per 1 tsp (~3 g), 75 servings at $18.44, so $0.087 per gram; 7 g a day takes 3servings and costs about $0.61, or $221 a year.
- Metamucil 4-in-1 Psyllium, Sugar-Free (72 servings) (Psyllium): 3.4 g of fiber per 1 rounded tsp (~5.8 g), 72 servings at $24.97, so $0.103 per gram; 7 g a day takes 3servings and costs about $0.72, or $263 a year.
- NOW Supplements Psyllium Husk Caps 500 mg (Psyllium): 1 g of fiber per 2 capsules, 100 servings at $15.99, so $0.510 per gram; 7 g a day takes 7servings and costs about $3.57, or $1303 a year.
The spread is the whole story of this category: the most expensive gram of fiber here costs 7.0 times the cheapest, and the expensive grams are not better grams. What the premium buys is a flavour system, a brand, or a different format (psyllium capsules if you don't want to mix a powder; inulin only to feed gut bacteria). If the goal is the 7 g claim dose or regularity, the plain husk at the top of the list is the answer, and the Metamucil vs NOW comparison shows the premium in one pair.
Frequently asked questions
What is the best fiber supplement?
For most people, plain psyllium husk powder, the best-evidenced fiber (FDA heart claim; RCTs for constipation and IBS) and the cheapest per gram of any well-evidenced fiber. Our pick is NOW Psyllium Husk Powder. Take it as capsules instead if you don't want to mix a powder, or choose inulin only to feed gut bacteria.
Is Metamucil or generic psyllium better?
Same active ingredient, psyllium. Metamucil adds flavor/sweetener, costs more per gram of fiber, and delivers a bit less psyllium per serving. Fine for taste; plain psyllium husk powder wins on value.
What is the best fiber for the money?
Plain psyllium husk powder, about $0.08 per gram of fiber, several times cheaper than psyllium capsules or branded blends. Inulin powder is similarly cheap but is a prebiotic, not a bulking fiber.
Related
- Fiber Types Compared: which fiber for constipation, cholesterol, IBS, or gut bacteria
- Fiber Dosage Guide: how much per day and how to ramp up
- Best Psyllium Supplement: a deeper psyllium-only ranking, including capsules and Metamucil
- All Fiber Guides
Sources
- van der Schoot A, et al. "The Effect of Fiber Supplementation on Chronic Constipation in Adults." Am J Clin Nutr. 2022. PMID: 35816465
- Nagarajan N, et al. "Fiber supplementation in irritable bowel syndrome." Eur J Gastroenterol Hepatol. 2015. PMID: 26148247
- McRorie JW Jr, McKeown NM. "Understanding the Physics of Functional Fibers in the Gastrointestinal Tract." J Acad Nutr Diet. 2017. PMID: 27863994
- U.S. FDA. "Health claims: Soluble fiber from certain foods and risk of coronary heart disease." 21 CFR 101.81.