Best Glucomannan 2026: Capsules vs Powder, Ranked by Cost per Gram
Informational summary — not medical advice. Prices are live Amazon prices, verified July 19, 2026; they change. This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.
Glucomannan is cheap fiber with a real EFSA weight-loss claim but underwhelming trial results — buy it for LDL/fiber, temper weight expectations, and respect the water rule. Ranked by cost per gram of glucomannan, plain powder wins by a wide margin over capsules; you're mostly choosing between dosing convenience and price, not efficacy. Top pick: Nutricost Glucomannan Powder (500g). All 5 verified products disclose glucomannan mg per serving on the label, so every row below is a real, computable cost-per-gram comparison — no undisclosed-grams asterisk needed here, unlike some fiber comparisons on this site.
As an Amazon Associate we earn from qualifying purchases. Ranked by cost per gram of glucomannan, never commissions.
| Item | Value |
|---|---|
| Nutricost | $0.050 |
| BulkSupplements.com | $0.082 |
| Nutricost | $0.157 |
| NOW Foods | $0.160 |
| Nature's Way | $0.188 |
The picks
Nutricost Glucomannan Powder (500g)
Pure konjac glucomannan powder, 2g per scoop — the cheapest cost per gram of glucomannan verified, and the only format that lets you dose exactly to the 3g EFSA weight-loss protocol (1.5 scoops) instead of rounding to a whole capsule count. Start here.
Check price on Amazon →BulkSupplements.com Glucomannan Powder from Konjac Root (500g)
The same pure powder format, no additives, from a different manufacturer — a real per-gram premium over Nutricost, but a reasonable pick if you want a second-source, single-ingredient powder.
Check price on Amazon →NOW Foods Glucomannan 575mg (180 Veg Capsules)
Cheapest capsule sticker price of the two capsule formats verified. Still costs meaningfully more per gram than powder, and needs about 5 capsules to approximate the 3g dose — a real convenience trade, not a value pick.
Check price on Amazon →The full ranking — cost per gram and cost per 3g EFSA dose
All 5 products disclose glucomannan grams per serving directly on the label, so cost per gram is a clean comparison across every row. We also show the realistic cost to reach the 3g/day EFSA weight-loss claim dose — for powder that's a continuous scoop measurement; for capsules it's the nearest whole capsule count (you can't take a fraction of a capsule).
| Product | Form | Glucomannan/serving | Price | Cost/g | Cost per 3g EFSA dose | |
|---|---|---|---|---|---|---|
| Nutricost — Glucomannan Powder (500g) | Powder | 2g | $24.95 | $0.050 | $0.15/day | Price → |
| BulkSupplements.com — Glucomannan Powder from Konjac Root (500g) | Powder | 2g | $40.97 | $0.082 | $0.25/day | Price → |
| Nutricost — Glucomannan 1,800mg per Serving (180 Capsules) | Capsule | 0.6g | $16.95 | $0.157 | $0.47/day (5 caps) | Price → |
| NOW Foods — Glucomannan 575mg (180 Veg Capsules) | Capsule | 0.575g | $16.52 | $0.160 | $0.46/day (5 caps) | Price → |
| Nature's Way — Glucomannan 665mg, Konjac Root (100 Capsules) | Capsule | 0.665g | $12.50 | $0.188 | $0.63/day (5 caps) | Price → |
Machine-readable version: /glucomannan/cost-by-brand.json (CC BY 4.0).
Nutricost works out to about $0.05/gram of glucomannan — roughly 4× cheaper than the priciest product here (Nature's Way) per gram of the identical active ingredient. With glucomannan, as with most fiber on this site, plain powder is the smart buy; capsules sell dosing convenience, not more or better fiber.
The capsule pill-burden math Every capsule product here needs roughly 5 capsules to approximate the 3g EFSA dose, regardless of brand: Nutricost (5 × 600mg = 3.00g, $0.47/day), NOW Foods (5 × 575mg = 2.88g, $0.46/day), Nature's Way (5 × 665mg = 3.33g, $0.63/day). Nutricost's 600mg capsules divide evenly into exactly 5 × 600mg = 3.0g — the cleanest dose math of the two capsule brands; NOW's 575mg and Nature's Way's 665mg both round less precisely. Either way, capsules cost 3.1×–3.8× more per gram than powder here — a real convenience-for-cost trade, not a value play. And every capsule still needs a full glass of water with it — capsules reduce texture and taste issues, not the choking risk.
How we ranked
Two things decide it, in order:
- Disclosure first. All 5 verified products state glucomannan mg per serving directly on the label, so every row here is ranked with confidence — no undisclosed-grams caveat needed for this comparison.
- Then cost per gram of glucomannan. Glucomannan grams are the unit behind every dose target in this cluster (EFSA weight-loss claim, EU cholesterol claim, the constipation dose) — not price per bottle, and not capsule count.
What we deliberately ignore: "appetite suppressant" and "fat blocker" marketing language not backed by the trial evidence (see our honest read on the weight-loss claim), and serving-size framing that makes a product look cheaper per bottle while actually costing more per effective gram.
Frequently asked questions
What is the best glucomannan supplement?
Plain glucomannan powder for most people — Nutricost is the cheapest cost per gram and lets you dose exactly. BulkSupplements for a clean-label alternative at a premium; NOW Foods capsules if you need pill-free-texture convenience and accept the cost/pill-burden trade.
Are glucomannan capsules a good deal?
Generally no — capsules cost meaningfully more per gram than powder and need about 5 capsules to approximate a 3g dose regardless of brand. Nutricost's 600mg capsules have the cleanest dose math (exactly 5 = 3.0g).
Is glucomannan safe in capsule form?
Yes, with a full glass of water every time — capsules solve texture, not the hydration requirement. Underhydrated capsules still carry real esophageal-obstruction risk.
Related
- Dosage Guide — how much by goal, plus the water rule
- Glucomannan for Cholesterol — the better-supported effect
- Does Glucomannan Cause Weight Loss? — the EFSA claim vs. the null RCTs
- All Glucomannan Guides
- Best Psyllium Supplement — the comparison fiber, if you're deciding between the two
Sources
- EFSA NDA Panel. Health claim for glucomannan and weight loss, authorized under Regulation (EU) No 432/2012: 3g/day, three 1g doses with 1–2 glasses of water before meals, in the context of an energy-restricted diet.
- Vanderbeek PB, Fasano C, O'Malley G, Hornstein J. "Esophageal obstruction from a hygroscopic pharmacobezoar containing glucomannan." Clin Toxicol (Phila). 2007. PMID: 17357389
- Henry DA, Mitchell AS, Aylward J, Fung MT, McEwen J, Rohan A. "Glucomannan and risk of oesophageal obstruction." Br Med J (Clin Res Ed). 1986. PMID: 3004635