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Head to head · Weight Management

NOW Foods Glucomannan 575 mg Veg Capsules vs Thorne Berberine (Dual Action Phytosome & HCl)

NOW Foods and Thorne finish level in our scoring (6.9 vs 6.9), so the right pick depends on what you value most — NOW Foods is stronger on value and transparency, Thorne on efficacy and quality & purity.

Updated September 2026 from our full reviews · How we score

Front of NOW Foods Glucomannan 575 mg 180-capsule bottle
NOW FoodsGlucomannan 575 mg Veg Capsules
6.9
Mixed

A cheap, single-ingredient konjac fiber (1,725 mg per serving) taken before meals for fullness. Honest and GMP-made, but the average weight effect in trials is small.

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Thorne Berberine Dual Action Formula 60-capsule bottle
ThorneBerberine (Dual Action Phytosome & HCl)
6.9
Mixed

NSF Contents Certified berberine in HCl and phytosome forms. Well made, but the average weight change in trials is about 2 lb and it interacts with many drugs.

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The short answer

Choose NOW Foods if…

  • Budget shoppers trying a pre-meal fiber
  • Anyone who wants a simple single-ingredient product
  • Vegan, gluten-free and keto diets
  • You care most about value, transparency

Choose Thorne if…

  • People whose clinician recommends berberine
  • Shoppers who want NSF-verified quality
  • Supporting healthy blood sugar and cholesterol alongside diet
  • You care most about efficacy, quality & purity

Side by side

Glucomannan 575 mg Veg CapsulesBerberine (Dual Action Phytosome & HCl)
Our score6.9 / 106.9 / 10
Efficacy (30%)4.55.5
Quality & Purity (25%)7.39.0
Value (20%)9.05.5
Experience (15%)7.07.0
Transparency (10%)9.08.0
FormCapsuleCapsule
Serving3 capsules60 servings per container2 capsules30 servings per container
Price per servingSee retailer$1.47
Testing & certifications
cGMP facilityKosherHalal
NSF Contents Certified
DietaryVegan, Vegetarian, Gluten-free, Dairy-free, Soy-free, Non-GMO, Keto-friendlyGluten-free, Dairy-free, Soy-free
Key ingredients
  • Glucomannan (from konjac root, Amorphophallus konjac)1,725 mg per serving (575 mg per capsule)
  • Berberine HCl (from Indian barberry root extract)450 mg
  • Berberine Phytosome550 mg
Flavors——
Creator video reviews13

Pros and cons

Glucomannan 575 mg Veg Capsules

  • About 28 cents a serving
  • A single ingredient with a fully disclosed dose (1,725 mg per serving)
  • NPA A-rated GMP; non-GMO, vegan, kosher and halal
  • Buyers often report feeling fuller before meals
  • The average weight effect in meta-analyses is small and not clinically meaningful
  • Choking risk if not taken with enough water
  • Three capsules per dose, up to six a day
  • Some users report cramps or bloating

Berberine (Dual Action Phytosome & HCl)

  • NSF Contents Certified and made in Thorne's own U.S. facility
  • Fully disclosed doses of two berberine forms
  • Berberine has a meaningful research base for metabolic markers
  • Gluten-, dairy- and soy-free
  • Average weight loss in trials is under 1 kg
  • Decreases CYP2D6, CYP2C9 and CYP3A4 activity, so it can interact with many drugs
  • About $1.47–2.93 a day, depending on dose
  • Digestive side effects are common when you start

Our verdicts

Glucomannan 575 mg Veg Capsules

NOW Glucomannan is cheap, cleanly formulated and honestly labeled, which puts it ahead of most weight-loss products. Keep expectations modest, though: trials show a small average weight difference at best. Treat it as an appetite aid alongside diet changes, and always take it with a full glass of water.

Full review

Berberine (Dual Action Phytosome & HCl)

Thorne Berberine is a well-made, NSF-certified version of the most researched 'metabolic' botanical, and a sensible choice if your clinician suggests berberine. Keep expectations in check, though: the average weight change in trials is about 2 pounds. Its drug-interaction profile also means it isn't something to add casually if you take prescription medications.

Full review

What creators say

Questions people ask

Is NOW Foods better than Thorne?
They score about the same in our reviews (6.9 vs 6.9 out of 10). NOW Foods leads on value and transparency; Thorne leads on efficacy and quality & purity. Choose based on the factors that matter most to you.
Are NOW Foods and Thorne third-party tested?
NOW Foods has no independent certification we could verify; Thorne carries NSF Contents Certified.
Who should choose NOW Foods over Thorne?
Our reviews suggest NOW Foods is best for budget shoppers trying a pre-meal fiber, anyone who wants a simple single-ingredient product and vegan, gluten-free and keto diets, while Thorne is best for people whose clinician recommends berberine, shoppers who want NSF-verified quality and supporting healthy blood sugar and cholesterol alongside diet.

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