Best Carb Blocker Supplements (2026)

Carb blocker supplements contain ingredients — most commonly white kidney bean extract (Phaseolus vulgaris) — that inhibit the alpha-amylase enzyme responsible for breaking down starchy carbohydrates. By reducing carb digestion and absorption, these supplements are used as a weight management tool, particularly for people who consume higher-carbohydrate diets and want to reduce caloric impact from starchy foods like bread, pasta, and potatoes.

Quick Comparison

Product	Key Ingredient	Form	Best For	Rating
Natures Craft White Kidney Bean Extract	White Kidney Bean Extract	Capsules	Best Overall	9.4/10
NOW Phase 2 White Kidney Bean Extract	Phase 2® WKB Extract	Veg Capsules	Best Clinically Studied	9.3/10
Arazo Nutrition White Kidney Bean Extract	White Kidney Bean 600mg	Capsules	Best Budget Pick	9.1/10
Carlyle White Kidney Bean	WKB Extract 6,000mg	Capsules	Best Value	9.0/10
Zazzee White Kidney Bean 10:1 Extract	WKB 10:1 Extract 1,800mg	Capsules	Best Concentrated Extract	8.9/10
Healthfare White Kidney Bean Extract	WKB Extract 7,500mg	Capsules	Best High Dose	8.8/10
Nobi Nutrition Night Time Fat Burner	WKB + Green Coffee + CLA	Capsules	Best Nighttime Formula	8.6/10

1. Natures Craft White Kidney Bean Extract – Best Overall

Natures Craft delivers a focused white kidney bean extract formula specifically designed for carb blocking and metabolism support, backed by the brand’s reputation for pure, responsibly-produced supplements.

Each serving provides a potent dose of white kidney bean extract to help ease calorie intake from starchy carbohydrates. The formula is designed to be taken approximately 15 minutes before the two largest carbohydrate-rich meals of the day. Natures Craft manufactures with a commitment to quality, using clean ingredients without unnecessary fillers. The capsule form is convenient and easy to integrate into a daily routine alongside a healthy diet and exercise plan.

• Pros:
• Pure white kidney bean extract focused on carb blocking
• Trusted brand with strong supplement reputation
• Easy pre-meal dosing protocol

• Cons:
• Requires taking before each major meal
• Results vary based on individual carb intake levels

Best for: Anyone wanting a straightforward, quality carb blocker from a reputable brand

2. NOW Phase 2 White Kidney Bean Extract – Best Clinically Studied

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NOW’s formula uses Phase 2®, the most extensively researched white kidney bean extract on the market with multiple clinical trials demonstrating its ability to reduce starch digestion and support weight management goals.

Each serving delivers 500mg of Phase 2® Starch Neutralizer per capsule with 120 capsules per bottle. Phase 2® is a patented, clinically studied white kidney bean extract shown to delay the breakdown of dietary starches by limiting alpha-amylase activity. Studies have demonstrated that participants using Phase 2® alongside diet and exercise lost significantly more weight than those using placebo alone. NOW Foods carries NPA A-rated GMP certification, and the product is non-GMO, vegan, and packaged in the USA.

• Pros:
• Uses patented Phase 2® clinically studied extract
• NPA A-rated GMP certified manufacturing
• Non-stimulant starch neutralizer

• Cons:
• Requires 3 capsules per serving before carb-heavy meals
• Only effective against starchy carbs, not sugars or fats

Best for: Users who want the most clinically validated carb blocking ingredient available

3. Arazo Nutrition White Kidney Bean Extract – Best Budget Pick

Arazo Nutrition provides 600mg of pure white kidney bean extract per capsule at an extremely competitive price point, delivering a full 60-day supply for budget-conscious carb blockers.

The formula is marketed as a 100% natural carb blocker and fat absorber derived from Phaseolus vulgaris. Each vegetarian capsule contains 600mg, and the recommended dose is one to two capsules before the biggest meals of the day. The supplement is manufactured in a GMP-certified facility in America and undergoes third-party safety testing for purity, ingredient safety, nutritional value, and label accuracy. White kidney bean extract also provides natural fiber and minerals as bonus nutritional support.

• Pros:
• Very affordable price per serving
• GMP certified and third-party tested
• 60-day supply per bottle

• Cons:
• Lower dose per capsule than some concentrated extracts
• Some users report mild digestive adjustment

Best for: Budget-minded shoppers wanting an affordable, effective carb blocker

4. Carlyle White Kidney Bean – Best Value

Carlyle packs the equivalent of 6,000mg of white kidney bean into each quick-release capsule, and with 200 capsules per bottle, this is one of the most generous supplies in the carb blocker category.

Drawing on over 40 years of family-owned supplement expertise, Carlyle uses a concentrated extract to deliver high-potency white kidney bean support in a single-capsule serving. The formula is naturally free of gluten, wheat, yeast, lactose, artificial flavors, and artificial sweeteners, and is non-GMO. All herbs are tested for purity and potency. The 200-count bottle provides outstanding value, especially for users who take carb blockers consistently with multiple meals daily.

• Pros:
• 200 capsules per bottle for extended supply
• 6,000mg equivalent per capsule
• Family-owned company with 40+ years in supplements

• Cons:
• Uses concentrated extract rather than whole-bean dosing
• Capsules contain gelatin (not vegan)

Best for: Consistent daily users who want a large bottle size with excellent per-serving value

5. Zazzee White Kidney Bean 10:1 Extract – Best Concentrated Extract

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Zazzee uses a concentrated 10:1 extraction ratio, meaning each capsule delivers the equivalent of 1,800mg of white kidney bean from just 180mg of extract, maximizing potency in a smaller dose.

Each bottle contains 200 vegan capsules for over a two-month supply. The 10:1 concentration ensures higher levels of the active alpha-amylase inhibiting compounds per capsule compared to standard extracts. Zazzee’s formula is 100% vegetarian, all-natural, and non-GMO, manufactured in the USA. The concentrated format means fewer capsules needed per serving and potentially more effective carb blocking per milligram.

• Pros:
• Concentrated 10:1 extract for higher potency
• 200 vegan capsules per bottle
• Made in the USA, non-GMO

• Cons:
• Concentrated extracts may vary in compound profiles
• Higher price than basic white kidney bean capsules

Best for: Users who prefer concentrated extracts and want maximum active compounds per capsule

6. Healthfare White Kidney Bean Extract – Best High Dose

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Healthfare pushes the dosage envelope with 7,500mg equivalent per capsule in a massive 240-count bottle, providing one of the most potent and longest-lasting carb blocker supplies available.

The extra-strength concentrated formula delivers substantially more white kidney bean extract per serving than most competitors. With 240 vegan capsules per bottle, this provides an exceptional multi-month supply even with daily use before meals. The formula is non-GMO, gluten-free, and made in the USA. Healthfare focuses on herbal supplement quality with clean ingredient lists and no unnecessary additives.

• Pros:
• Highest dosage at 7,500mg equivalent per capsule
• 240 vegan capsules for extended supply
• Non-GMO, gluten-free, made in USA

• Cons:
• Ultra-high concentration may not be needed for all users
• Less brand recognition than established supplement companies

Best for: Users who want maximum white kidney bean dosage per capsule

7. Nobi Nutrition Night Time Fat Burner – Best Nighttime Formula

This unique formula combines white kidney bean extract as a carb blocker with green coffee bean, CLA, and other nighttime-support ingredients to work while you sleep.

Unlike standard carb blockers that are taken before meals, this formula is designed for evening use, combining carb-blocking action with ingredients that support overnight metabolism and restful sleep. The white kidney bean extract component inhibits carb absorption from dinner, while additional ingredients promote fat metabolism during sleep. The formula also includes ingredients to support relaxation without stimulants, making it safe for evening consumption.

• Pros:
• Combines carb blocking with nighttime metabolic support
• Stimulant-free formula safe for evening use
• Multi-action weight management approach

• Cons:
• Lower white kidney bean concentration than standalone carb blockers
• Multi-ingredient formula dilutes carb-blocking focus

Best for: Users who want combined carb blocking and nighttime metabolic support

8. BioGenetic Laboratories Carb Blocker X7 – Best Multi-Action Formula

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Carb Blocker X7 combines white kidney bean extract with additional appetite suppressant ingredients for a comprehensive carb and calorie management approach that goes beyond basic starch blocking.

This keto-friendly formula uses white kidney bean extract as its core carb-blocking ingredient while adding complementary compounds to suppress appetite and support overall calorie control. The multi-action approach makes it suitable for users following various dietary patterns, including ketogenic and low-carb diets where accidental carb intake can disrupt progress. Each bottle provides 90 capsules.

• Pros:
• Multi-action carb blocking plus appetite control
• Keto-friendly formulation
• Supports multiple weight management pathways

• Cons:
• More expensive than single-ingredient carb blockers
• Complex formula may not suit those wanting pure white kidney bean

Best for: Keto dieters and those wanting combined carb blocking with appetite suppression

How to Choose the Best Carb Blocker Supplement

The gold standard active ingredient for carb blocking is white kidney bean extract (Phaseolus vulgaris), which inhibits alpha-amylase, the enzyme that breaks down starchy carbohydrates. Look for products that specifically list white kidney bean extract as the primary ingredient. The patented Phase 2® extract has the most clinical research behind it, but other quality white kidney bean extracts can also be effective. Concentrated extracts (10:1, 20:1) deliver more active compounds per capsule.

Dosage typically ranges from 500mg to 3,000mg of white kidney bean extract per serving, depending on concentration. Clinical studies commonly use 1,000–3,000mg of standard extract or equivalent amounts of concentrated extracts. Take carb blockers 15 to 30 minutes before meals containing starchy carbohydrates for best results. They are most effective with meals high in complex carbs like bread, pasta, rice, and potatoes — they do not block simple sugars or dietary fats.

Choose between standalone white kidney bean products and combination formulas based on your goals. Standalone products offer the purest carb-blocking action, while combination formulas may add metabolism boosters, appetite suppressants, or fat-blocking ingredients. Standalone products tend to be more cost-effective and transparent in their dosing.

Quality markers include GMP certification, third-party testing, and clean ingredient lists free of unnecessary fillers. Vegan capsules are preferred by many users, though some budget options use gelatin. Look for non-GMO and allergen-free certifications based on your dietary needs.

Frequently Asked Questions

What are carb blockers and how do they work?

Carb blockers, primarily made from white kidney bean extract, work by inhibiting alpha-amylase, a digestive enzyme that breaks down starchy carbohydrates into simple sugars for absorption. By blocking this enzyme, a portion of the starchy carbs you eat passes through your digestive system without being fully broken down or absorbed, effectively reducing the caloric impact of carb-heavy meals. They target complex carbohydrates like bread, pasta, rice, and potatoes.

How much white kidney bean extract should I take?

Clinical studies typically use 500–3,000mg of white kidney bean extract per day, taken before meals containing starchy carbohydrates. The Phase 2® extract is commonly dosed at 1,500mg (three 500mg capsules) before carb-heavy meals. Concentrated extracts (10:1 or 20:1) require lower milligram doses to achieve equivalent effects. Follow the manufacturer’s recommended serving size for the specific product you choose.

When should I take carb blocker supplements?

Take carb blockers 15 to 30 minutes before meals that contain significant amounts of starchy carbohydrates. This timing allows the alpha-amylase inhibitors to be present in your digestive system before the starch arrives. Most users take them before lunch and dinner, as these meals tend to be highest in carbs. Taking them with or after a meal significantly reduces their effectiveness.

Do carb blockers block all types of carbohydrates?

No. White kidney bean extract specifically blocks the digestion of complex starches (amylose and amylopectin) by inhibiting alpha-amylase. It does not block simple sugars like glucose, fructose, or sucrose, nor does it block fiber or dietary fats. For this reason, carb blockers are most effective with starchy foods like bread, pasta, potatoes, and rice, but will have little effect on sugary foods, fruits, or fatty meals.

Are there any side effects of carb blocker supplements?

The most common side effects are digestive in nature, including gas, bloating, diarrhea, and stomach discomfort. These occur because undigested starches pass into the large intestine where gut bacteria ferment them, producing gas. These effects typically decrease as the body adjusts over one to two weeks. Starting with a lower dose and gradually increasing can help minimize initial digestive discomfort.

How long does it take for carb blockers to show results?

Some users notice reduced bloating and less post-meal blood sugar spikes within the first few days. For measurable weight management results, clinical studies show meaningful differences after 8 to 12 weeks of consistent use combined with a sensible diet and exercise program. One study found participants lost an average of 6.4 pounds over 12 weeks with Phase 2® supplementation. Individual results will vary based on diet composition and overall lifestyle habits.