We reviewed 15+ glucomannan supplements across dose per serving, form (capsule vs powder), serving convenience, third-party testing, and value. Our picks prioritize products that deliver clinically effective doses in a safe, convenient format.
Best Glucomannan Supplements (2026)
This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer
Our Verdict
The best glucomannan supplement provides 1-3g of konjac glucomannan per serving in capsule form, taken 30 minutes before meals with a full glass of water for effective appetite management and regularity.
Best By Category
TL;DR — Quick Answer
The best glucomannan supplement provides 1-3g per serving in capsules taken with a full glass of water 30 minutes before meals. Glucomannan is the most viscous dietary fiber known, absorbing up to 50x its weight in water to promote fullness. Capsules are strongly preferred over powder for safety and dosing accuracy.
Our recommendations are based on published research, not commission rates. Some links below are affiliate links — we may earn a commission at no extra cost to you. How we evaluate products
3+ products evaluated · Ratings based on published research, not commissions
Quick Comparison
#1NOW Foods Glucomannan 575mg
9/10
NOW Foods
Best for: Best overall glucomannan supplement
Konjac Glucomannan (Amorphophallus konjac root) · 575mg glucomannan per capsule (3 capsules = 1,725mg per serving)
Capsule · GMP Certified, Third-Party Tested
$0.12
#2Nutricost Glucomannan 1,800mg
8.7/10
Nutricost
Best for: Best value glucomannan
Konjac Root Glucomannan · 1,800mg glucomannan per serving (3 capsules)
Capsule · Third-Party Tested
$0.09
#3Nature's Way Glucomannan from Konjac Root
8.8/10
Nature's Way
Best for: Best brand recognition and TRU-ID certified
Konjac Root Glucomannan · 1,995mg glucomannan per serving (3 capsules)
Capsule · TRU-ID Certified, Third-Party Tested
$0.14
| # | Product | Best For | Ingredient & Dose | Form & Testing | Price | Rating | |
|---|---|---|---|---|---|---|---|
| 1 | NOW Foods Glucomannan 575mg NOW Foods | Best overall glucomannan supplement | Konjac Glucomannan (Amorphophallus konjac root) 575mg glucomannan per capsule (3 capsules = 1,725mg per serving) | Capsule GMP Certified, Third-Party Tested | $0.12 | 9/10 | |
| 2 | Nutricost Glucomannan 1,800mg Nutricost | Best value glucomannan | Konjac Root Glucomannan 1,800mg glucomannan per serving (3 capsules) | Capsule Third-Party Tested | $0.09 | 8.7/10 | |
| 3 | Nature's Way Glucomannan from Konjac Root Nature's Way | Best brand recognition and TRU-ID certified | Konjac Root Glucomannan 1,995mg glucomannan per serving (3 capsules) | Capsule TRU-ID Certified, Third-Party Tested | $0.14 | 8.8/10 |
Detailed Reviews
Top Pick
1
NOW Foods Glucomannan 575mg
NOW Foods
9/10
$0.12/serving
Ingredient: Konjac Glucomannan (Amorphophallus konjac root)
Dose: 575mg glucomannan per capsule (3 capsules = 1,725mg per serving)
Form: Capsule
Testing: GMP Certified, Third-Party Tested
575mg glucomannan per capsule (3 capsules = 1,725mg per serving)Clinical range: 1-4g daily (1g before each meal)
Clinical dose
Why we recommend it: Delivers 1,725mg (1.7g) glucomannan per 3-capsule serving — well within the clinical dose range. NOW Foods is a GMP-certified manufacturer with 50+ years of quality history. Capsule form is safe and convenient. At $0.12/serving, it offers the best combination of dose, quality, and value.
Ideal for: Best overall glucomannan supplement
Not ideal for: Those who dislike taking multiple capsules per serving.
Pros
- Clinical dose (1.7g per serving)
- GMP-certified, third-party tested
- Best overall value at $0.12/serving
- Safe capsule form
Cons
- Requires 3 capsules per serving
- Must take with full glass of water
- Moderately large capsules
- Unflavored
2
Nutricost Glucomannan 1,800mg
Nutricost
8.7/10
$0.09/serving
Ingredient: Konjac Root Glucomannan
Dose: 1,800mg glucomannan per serving (3 capsules)
Form: Capsule
Testing: Third-Party Tested
1,800mg glucomannan per serving (3 capsules)Clinical range: 1-4g daily (1g before each meal)
Clinical dose
Why we recommend it: Delivers a generous 1,800mg (1.8g) per 3-capsule serving at the lowest price on our list. Third-party tested for purity. Nutricost focuses on simple, effective, no-frills formulations at competitive prices. 180-capsule bottle provides 60 servings — a two-month supply when taken once daily.
Ideal for: Best value glucomannan
Not ideal for: Those wanting a premium brand or additional fiber types.
Pros
- Best value at $0.09/serving
- 1.8g per serving (clinical dose)
- Third-party tested
- 60 servings per bottle
Cons
- Less established brand
- Limited sourcing information
- No GMP certification listed
- Basic no-frills product
3
Nature's Way Glucomannan from Konjac Root
Nature's Way
8.8/10
$0.14/serving
Ingredient: Konjac Root Glucomannan
Dose: 1,995mg glucomannan per serving (3 capsules)
Form: Capsule
Testing: TRU-ID Certified, Third-Party Tested
1,995mg glucomannan per serving (3 capsules)Clinical range: 1-4g daily (1g before each meal)
Clinical dose
Why we recommend it: Highest dose per serving on our list at nearly 2g per 3-capsule serving. Nature's Way is one of the most trusted herbal supplement brands with TRU-ID certification — DNA-based authenticity testing that verifies the plant species used. Established brand with wide retail availability. Delivers a robust clinical dose.
Ideal for: Best brand recognition and TRU-ID certified
Not ideal for: Budget-focused shoppers who can find equal quality for less.
Pros
- Highest dose (2g per serving)
- TRU-ID certified (DNA-verified species)
- Trusted heritage brand
- Widely available
Cons
- Slightly higher price ($0.14/serving)
- Requires 3 capsules
- Premium for brand recognition
- No added prebiotics or fiber types
How to Choose
How to Take Glucomannan Safely
Always take glucomannan capsules with at least 8oz (250ml) of water 30-60 minutes before a meal. Never take glucomannan powder dry or with insufficient water — it can expand in the throat and cause choking. Capsule form ensures the fiber reaches the stomach before expanding. Start with 1g per day and increase gradually to reduce GI side effects like bloating.
Dosing for Weight Management
Clinical trials use 1-4g glucomannan daily, typically split as 1g before each of three main meals. A 2005 meta-analysis (Sood et al.) found that glucomannan supplementation at 2-4g daily led to modest but significant weight loss compared to placebo. Effects are amplified when combined with a calorie-controlled diet.
How We Evaluate
Every product is scored against these weighted criteria. Our ratings reflect clinical evidence and product quality, not commission rates.
Dose Adequacy
30%Clinical trials showing weight management and satiety benefits use 1-4g glucomannan daily, typically 1g before each of three meals. Products should deliver at least 1g per serving for clinical relevance.
Safety & Form
25%Capsules are strongly preferred over loose powder because glucomannan expands rapidly and can cause choking if powder contacts the throat before reaching the stomach. Always take with a full glass of water.
Convenience
20%Fewer capsules per serving improves compliance. Products requiring 5+ capsules per serving are less convenient than those delivering adequate doses in 2-3 capsules.
Third-Party Testing
15%Independent verification ensures konjac glucomannan purity and accurate fiber content per serving.
Value
10%Cost per gram of glucomannan, adjusted for form and serving convenience.
Frequently Asked Questions
Does glucomannan actually help with weight loss?
Does glucomannan actually help with weight loss?
Yes, modestly. A 2005 systematic review found that glucomannan supplementation (2-4g daily before meals) produced significant weight loss compared to placebo. The mechanism is mechanical — glucomannan absorbs water and expands in the stomach, promoting fullness and reducing calorie intake at the subsequent meal. Results are best when combined with a calorie-controlled diet.
Is glucomannan safe?
Is glucomannan safe?
Glucomannan is generally safe when taken as capsules with plenty of water. The main risk is esophageal obstruction if taken as dry powder without adequate liquid. Always take with at least 8oz of water. Common side effects include bloating, gas, and loose stools, which typically resolve as the body adjusts. Glucomannan may delay absorption of oral medications — take medications 1 hour before or 4 hours after.
References
- Sood N, Baker WL, Coleman CI (2008). Effect of glucomannan on plasma lipid and glucose concentrations, body weight, and blood pressure: systematic review and meta-analysis. American Journal of Clinical Nutrition. DOI PubMed
- EFSA Panel on Dietetic Products, Nutrition and Allergies (2010). Scientific opinion on the substantiation of health claims related to konjac mannan (glucomannan). EFSA Journal. DOI