Fiber Supplement Price Guide: Cost Per Gram

Fiber is the one shelf in the store where the number on the front of the bottle and the number on the back almost never agree. A psyllium capsule says 500 milligrams on the label, and the panel behind it prints a Dietary Fiber line that is a quarter to a third smaller than that weight, because husk is a plant material and fiber is only part of it. Powders go further: the same aisle sells a 24-ounce bottle whose label serving is a tablespoon, a 12-ounce one whose serving is two tablespoons, and a bottle whose serving is a single teaspoon — three serving sizes spread across products that look interchangeable. This guide puts the whole shelf on one ruler that survives all of that: the dollar cost of one gram of dietary fiber, computed from the live prices on supplement.deals and the Supplement Facts panels behind every row.

We pulled 612 fiber-worded listings with a live price on October 24, 2026. Fifteen carried a counted capsule format with a milligram figure in the name, 104 more were powders sold by the ounce, and not one gummy appeared anywhere in the aisle — the fiber gummy shelf that exists at drugstores simply has no counted, priced counterpart on this catalog. We clicked through to 28 retailer pages, read 15 panels cleanly enough to price, and fifteen bottles made the tables below. Every exclusion, and the reason for it, is named near the end.

Corrected rate = price divided by (servings per container times panel fiber grams per serving), stated as the cost of one gram of fiber. The panel prints the fiber; the name only prints the plant.

How we priced the shelf

Every row is priced the same way: the panel states Dietary Fiber per serving, the label states servings per bottle, and the price divides the product of the two. For capsules we use the label serving — three capsules at Now, two at Sunergetic, six at Vitamin World — and the bottle count divided by that serving size gives the servings, which is exactly the number the labels themselves print where we could see it (the 200-capsule Now bottle prints 66). For powders the serving is a spoon measure, and the printed serving count is used wherever the panel shows one; the two Foster and Thrive powders print no serving count, so their servings come from net weight over serving size, stated here so the arithmetic can be checked. Nothing is priced off the name number: the milligrams on the front are husk weight, and the panels show that only 69 to 89 percent of that weight is fiber depending on the brand. Our psyllium and fiber ingredient pages catalog the plant sources and the soluble-versus-insoluble split; this guide prices the bottles. The same per-unit method priced magnesium, calcium, and omega-3 fish oil in earlier guides.

The verified powder shelf, cheapest per gram first

Eleven powders made the table. The floor is the 24-ounce tub of Now psyllium husk powder at 3.8 cents per gram of fiber — 525 grams of fiber for twenty dollars. The most expensive way to buy fiber on the shelf is the smallest: Life Extension Easy Fiber, whose one-gram servings put it at 25.5 cents per gram, 6.7 times the floor. Between them sit two organic psyllium powders, an apple fiber, two orange-flavored psyllium blends, and three prebiotic-class soluble fibers.

Two rows deserve a second look. Source Naturals and Dr. Mercola print identical panel math — a 5-gram serving carrying 4 grams of fiber, 68 servings per 12-ounce bottle — and carry the identical price, $13.99, down to the cent. When two brands from different price tiers land on the same per-gram rate, the aisle is telling you where the commodity price of psyllium powder sits. And the Now powder pair prices the size ladder: the 24-ounce tub costs 9.5 percent less per gram of fiber than the 12-ounce one, which is real but modest next to the 20.5 percent the capsule ladder pays for buying the big bottle.

The capsule shelf: paying for husk, priced by fiber

Four capsule products survived verification, and they make the honest-billing problem visible in a way the powders cannot. Now's 500-milligram capsule carries 1.1 grams of fiber per three-capsule serving — 73 percent of its husk weight. Sunergetic's 725-milligram capsule carries 69 percent. Vitamin World's 4,500-milligram serving name is six capsules of 750 milligrams each, and its panel prints 4 grams of fiber — the best conversion on the capsule shelf at 89 percent. None of that is visible from the front of the bottle; the front prints the plant, the panel prints the fiber.

The capsule ladder is the aisle's clearest size premium: the 500-capsule Now bottle prices 20.5 percent below its own 200-capsule sibling per gram of fiber, and even the discounted big bottle starts at three times the per-gram rate of the powder floor. Capsules are convenience packaging, and this aisle charges about a factor of three for it.

The premium soluble fibers

Three powders sit far above the psyllium floor because they are selling a different ingredient. Clearly Fiber is digestion-resistant maltodextrin — 5 grams of fiber per 5.85-gram scoop at 14 cents per gram, 3.7 times the floor. Vital Planet's Vital Fiber is a food-blend powder whose two-scoop, 22-gram serving carries 13 grams of fiber across just 10 servings per bottle — 20.8 cents per gram. Life Extension Easy Fiber is the sharpest lesson on the shelf: 90 servings per bottle sounds like a year of supply until the panel shows one gram of fiber per serving, which puts the small 5.89-ounce bottle at 25.5 cents per gram of fiber, the ceiling of this guide. Servings per bottle is the aisle's most misleading big number; per-gram pricing dissolves it.

What the shelf does not print

Fifteen rows made the tables; the rest of the aisle failed one of five checks, and each failure is itself a fact about how fiber is sold.

No gummies. The catalog carries zero counted, priced fiber gummies — the format this series has repeatedly caught hiding per-serving math on other shelves does not exist in the fiber aisle here. There is nothing to price, which is the finding.

No fiber line. Both Now acacia powders print 6 grams of total carbohydrate per serving but no Dietary Fiber line at all — a fiber supplement whose fiber content is never stated on the panel. The two polycarbophil products are named fiber laxatives, sold over the counter as laxatives, and their panels state the polymer dose with no fiber grams anywhere; they are not dietary fiber supplements and were priced out on principle. The Vitamin Shoppe capsule panel prints its 720-milligram husk weight and nothing else.

Unreadable panels. The Micro Ingredients 3,000-milligram, 500-capsule bottle is the arithmetic floor of the entire aisle on name math — and its retailer panel is printed only on label images that cannot be read as text. This guide does not price what it cannot verify, so the aisle's cheapest-looking bottle is excluded and named.

Label conflicts. The Now 24-ounce whole-husk page displays the 12-ounce label's serving count — 34 servings where a 24-ounce bottle at two tablespoons per serving implies 68. The Garden of Life Raw Fiber label says 30 servings at 20 grams, which sums to 600 grams in a 349-gram bottle. Both were excluded rather than reconciled by guesswork.

Dead listings. Micro Ingredients 1,500-milligram, 500-capsule and Now Psyllium with Pectin flipped to unavailable between the morning pull and the check. Three retailer pages — Swanson Bio-Fiber, Nutricost psyllium 90-count, and The Vitamin Shoppe 720-milligram 100-count — return 404 at the retailer while our listings still display prices. Dead links are excluded automatically.

How to compare any two bottles

Three steps survive every trap on this shelf. Read the panel, not the front: the Dietary Fiber line per serving is the only number that counts. Divide the bottle: servings per container times fiber per serving is the fiber you are actually buying — and check that serving size, because 66 servings of one gram and 20 servings of four grams are not the same bottle. Divide the price by that total and compare per gram; everything else on the label is merchandising. A 7-gram day — one tablespoon of the floor tub — costs 27 cents from the 24-ounce Now powder, 36 cents from the Source Naturals or Mercola tubs, 87 cents from the cheapest capsules, and $1.79 from the Easy Fiber bottle. Over a year of 7-gram days that is $97 against $653, the widest spread this series has recorded on a single aisle. The psyllium husk page catalogs the whole ingredient family, and the vitamin E and zinc guides apply the same per-unit arithmetic to other shelves.