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White kidney bean extract

An independent 2011 meta-analysis found weight change that did not differ significantly from placebo and judged every trial seriously flawed. Later meta-analyses found 1.08 kg (maker-funded) and 1.62 kg more weight loss. Pooled fat loss ranged from 1.17 to 3.26 kg. Most trials tested one branded extract. In Japan, over 1,000 people fell ill after eating undercooked powdered beans.

Add to Bio HackChecked 2026-11-09
Status
Dietary supplement in the US.
Also called
Phaseolus vulgaris extract, white bean extract, phaseolamin, alpha-amylase inhibitor, starch blocker, carb blocker, Phase 2, Phase 2 Carb Controller, Glucosanol, StarchLite
Taken for
weight loss, carb blocking, fat loss, blood sugar, appetite

Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on

Shown to help3

Reported risks2

What people take it for, and what was found

Shown to help3

Strong

Body fat

Shown to lower body fat about 1.2 to 1.9 kg more than placebo in overweight and obese adults, in flawed and partly maker-funded trials.

The numbers and sources
Effect
The independent meta-analysis found fat loss 1.86 kg greater than placebo (95% CI -3.39 to -0.32) [1]. The maker-funded meta-analysis found 3.26 kg more fat loss across 3 studies with 110 subjects [2]. The 2026 meta-analysis found 1.17 kg more fat loss (95% CI -1.80 to -0.55) and a waist reduction of 1.58 cm [5]. In the 12-week trial, fat mass fell 3.17 kg with 1,000 mg three times a day against 0.65 kg with placebo, and the 2.06 kg loss at 700 mg did not differ significantly from placebo [3]. Fat-free mass also fell 1.42 kg at the higher dose, against a 0.12 kg gain with placebo [3].
Population
Overweight and obese adults [1][2][3][5].
Sources
[1], [2], [3], [5]
Caveats
Same quality and funding limits as the weight outcome.
Limited

Blood sugar

One trial found HbA1c fell 0.72% more than placebo over 4 months in adults with type 2 diabetes. Overweight adults showed no glucose change.

The numbers and sources
Effect
In 90 adults with type 2 diabetes, 1.5 g of white bean extract before meals for 4 months lowered HbA1c by 0.72% against maltodextrin placebo, with fewer participants scoring in the peripheral neuropathy range [6]. In 13 healthy adults eating white bread, the glycemic index fell 34% with 3,000 mg of powder. Capsule doses of 1,500 to 3,000 mg and powder doses of 1,500 and 2,000 mg did not change it significantly [7]. Across trials in overweight and obese adults, fasting blood glucose and insulin did not differ from placebo [5].
Population
Adults with type 2 diabetes in China [6]; 13 adults in an open-label crossover [7]; overweight and obese adults in 8 RCTs [5].
Sources
[5], [6], [7]
Caveats
[7] was open-label and supported by Pharmachem, and its lead author consulted for the company. The trial in [6] was publicly funded.
Limited

Appetite

Small trials found less desire to eat after one meal with a bean extract, and more fullness over 2 months with a bean and artichoke blend, against placebo.

Compared with placebo [9][10]

The numbers and sources
Effect
In 12 healthy volunteers, 100 mg of a bean extract with a mixed meal lowered the desire to eat over 3 hours against placebo (P = 0.02), and blood ghrelin did not rebound in the third hour as it did on placebo (P = 0.04) [9]. In 39 overweight adults, an extract of Phaseolus vulgaris with artichoke (Cynara scolymus) for 2 months raised satiation scores and lowered the susceptibility-to-hunger score, which did not change on placebo [10]. In rats, a bean extract lowered food intake and body weight gain in a dose-dependent way, an effect blocked by a CCK receptor antagonist [11].
Population
12 healthy volunteers, one meal [9]. 39 overweight adults, 20 on the blend and 19 on placebo [10]. Rats [11].
Sources
[9], [10], [11]
Caveats
Two small trials. The first tested a single meal [9], and the second a combination with artichoke, so the bean extract's share is unknown [10]. Appetite was self-rated.

Mixed results1

Moderate

Weight loss

Mixed results: an independent review found no significant weight loss, while maker-funded and newer reviews found about 1 to 1.6 kg more than placebo in overweight adults.

The numbers and sources
Effect
An independent meta-analysis of 6 RCTs found weight loss 1.77 kg greater with Phaseolus vulgaris, a difference that was not statistically significant (95% CI -3.33 to 0.33) [1]. A meta-analysis of one branded extract, including unpublished manufacturer data, found 1.08 kg more weight loss across 11 studies with 573 subjects [2]. In 81 adults with overweight or moderate obesity on a calorie-restricted diet, the branded extract taken three times a day before meals for 12 weeks lowered weight 4.48 kg at 1,000 mg and 3.18 kg at 700 mg, against 0.54 kg with placebo [3]. In an independently funded Chinese trial in obese adults, 2,400 mg a day for 35 days lowered weight 2.24 kg against 0.29 kg with placebo [4]. A 2026 meta-analysis of 8 RCTs (543 participants) found 1.62 kg more weight loss than placebo (95% CI -1.99 to -1.25) and a BMI drop of 0.58 kg/m² [5].
Population
Overweight and obese adults in RCTs [1][2][3][4][5].
Sources
[1], [2], [3], [4], [5]
Caveats
All RCTs in [1] had serious methodological flaws, and heterogeneity was evident. [2] was funded by Pharmachem Laboratories, which makes Phase 2. [3] was financially supported by Perrigo, Pharmachem and Fytexia, and one author declared a conflict. The funding of the 2026 meta-analysis is not stated in its abstract [5].

Doses studied

The 12-week branded trial used 700 or 1,000 mg three times a day, 30 minutes before meals [3]. The Chinese weight trial used 2,400 mg a day before meals for 35 days [4], and the diabetes trial 1.5 g before a meal for 4 months [6]. The glycemic index study tested 1,500, 2,000 and 3,000 mg taken with white bread [7].

Risks

Reported risks2

Limited

Lectin poisoning from undercooked beans

Case reports: in Japan, over 1,000 people had acute gut symptoms and 100 were hospitalized after eating undercooked white kidney bean powder.

The numbers and sources
Effect
In Japan in 2006, after a television program promoted eating powdered toasted white kidney beans with meals, more than 1,000 viewers who tried it had acute intestinal symptoms and 100 were hospitalized. Testing found the heat treatment shown on the program left lectin activity in the beans [8].
Population
Members of the public in Japan [8].
Sources
[8]
Caveats
This involved home-prepared bean powder, not commercial standardized extracts.
Limited

Manufacturer involvement in the evidence

The maker, Pharmachem, funded the meta-analysis and trials showing significant weight loss. The independent meta-analysis found no significant weight change.

The numbers and sources
Effect
The 2018 meta-analysis reporting significant weight and fat loss was funded by Pharmachem Laboratories and drew on its internal unpublished data [2]. The 12-week trial [3] and the glycemic index study [7] were also supported by Pharmachem. The trials independent of the maker were the Chinese trials [4][6], while the independent meta-analysis [1] found weight change that did not differ significantly from placebo.
Population
Published trials and reviews [1][2][3][4][6][7].
Sources
[1], [2], [3], [4], [6], [7]
Caveats
Funding for some trials pooled in [1] is not reported in its abstract.

Checked, no increase found1

Limited

Side effects in trials

Small trials found few adverse events, with one case of bloating possibly related and no serious events tied to the extract.

The numbers and sources
Effect
In the 12-week trial, 19 adverse events occurred in 19 of 90 participants across all groups. Only one, bloating, was judged possibly related to the extract [3]. The Chinese 35-day trial observed no adverse effects [4]. Across 8 RCTs, no serious adverse events related to the extract were reported [5].
Population
RCT participants [3][4][5].
Sources
[3], [4], [5]
Caveats
Trials were small and short.

Claims tested and not found

  1. That white bean extract capsules lower the glycemic index of bread. Capsule doses of 1,500 to 3,000 mg did not change the glycemic index significantly [7].

Sources

  1. Onakpoya I, Aldaas S, Terry R, et al. The efficacy of Phaseolus vulgaris as a weight-loss supplement: a systematic review and meta-analysis of randomised clinical trials. British Journal of Nutrition. 2011. https://doi.org/10.1017/s0007114511001516
  2. Udani J, Tan O, Molina J. Systematic Review and Meta-Analysis of a Proprietary Alpha-Amylase Inhibitor from White Bean (Phaseolus vulgaris L.) on Weight and Fat Loss in Humans. Foods. 2018. https://doi.org/10.3390/foods7040063
  3. Jäger R, Abou Sawan S, Purpura M, et al. Proprietary alpha-amylase inhibitor formulation from white kidney bean (Phaseolus vulgaris L.) promotes weight and fat loss: a 12-week, double-blind, placebo-controlled, randomized trial. Scientific Reports. 2024. https://doi.org/10.1038/s41598-024-63443-8
  4. Wang S, Chen L, Yang H, et al. Regular intake of white kidney beans extract (Phaseolus vulgaris L.) induces weight loss compared to placebo in obese human subjects. Food Science & Nutrition. 2020. https://doi.org/10.1002/fsn3.1299
  5. Shi N, Wang R, Cao X, et al. White kidney bean extract reduces body weight and adiposity with acceptable safety in adults with overweight and obese: a systematic review and meta-analysis. Nutrition Research. 2026. https://doi.org/10.1016/j.nutres.2026.04.001
  6. Feng Y, Zhu J, Wang Q, et al. White common bean extract remodels the gut microbiota and ameliorates type 2 diabetes and its complications: A randomized double-blinded placebo-controlled trial. Frontiers in Endocrinology. 2022. https://doi.org/10.3389/fendo.2022.999715
  7. Udani JK, Singh BB, Barrett ML, et al. Lowering the glycemic index of white bread using a white bean extract. Nutrition Journal. 2009. https://doi.org/10.1186/1475-2891-8-52
  8. Ogawa H, Date K. The "White Kidney Bean Incident" in Japan. Methods in Molecular Biology. 2014. https://doi.org/10.1007/978-1-4939-1292-6_3
  9. Spadafranca A, Rinelli S, Riva A, et al. Phaseolus vulgaris extract affects glycometabolic and appetite control in healthy human subjects. British Journal of Nutrition. 2013. https://doi.org/10.1017/s0007114512003741
  10. Rondanelli M, Giacosa A, Orsini F, et al. Appetite control and glycaemia reduction in overweight subjects treated with a combination of two highly standardized extracts from Phaseolus vulgaris and Cynara scolymus. Phytotherapy Research. 2011. https://doi.org/10.1002/ptr.3425
  11. Fantini N, Cabras C, Lobina C, et al. Reducing effect of a Phaseolus vulgaris dry extract on food intake, body weight, and glycemia in rats. Journal of Agricultural and Food Chemistry. 2009. https://doi.org/10.1021/jf900711z

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