White Bean Extract

Last updated: May 8, 2013

White Bean Extract or White Kidney Bean Extract is marketed as a weight loss aid. It’s also sometimes called Phaseolamin or Phase 2. It’s claimed to “block” the absorption of carbohydrates to help people lose weight. In this article, we’ll examine:

  • What is white bean extract?
  • What evidence is there that white bean extract helps you lose weight?
  • What are the side effects of white bean extract?

What is White Bean Extract?

The white bean or white kidney bean is a variety of the common beanIt’s popular in Italy where it’s called the cannellini bean.

Most of the most popular beans in the world are actually just a variety of the same species, called the common bean (or Phaseolus vulgaris to give it the scientific name). Aside from white beans, other varieties in this species include:

  • Black beans
  • Green beans
  • Pinto beans
  • Kidney beans

Although they’re all part of the same species, each variety of bean has different nutritional properties.

White beans are particularly high in a type of natural plant compound called phaseolamin.

White bean extract is made by a specially formulated process that uses pure water to extract the beneficial compounds from white kidney beans while leaving behind any compounds which might cause gastrointestinal distress (more on that in just a minute).

White Bean Extract for Weight Loss

White bean extract is claimed to aid weight loss by blocking the process of carbohydrate digestion in your body.

First, a short primer on how you body digests carbohydrates normally.

You’ve probably heard the phrase “complex carbohydrates” before. A complex carbohydrate is simply a carbohydrate that has many individual units held together by molecular bonds. A common complex carbohydrate is starch, which is the main energy source in foods like bread, potatoes, rice and pasta.

Starch is made of units of glucose, a type of sugar and the body’s primary source of energy. When your body takes in glucose that it can’t use immediately, it stores the energy as fat.

When you eat starch, it’s broken down in your body into glucose. This is done by an enzyme called amylase.

There’s a compound found naturally in white beans called an amylase inhibitor. It interferes with the action of amylase, which causes your body to break down less starch into glucose.

Your body can’t process starch unless it’s first converted into glucose. Glucose is absorbed through the walls of the intestine, but starch passes straight through your digestive tract.

So, scientists believe in white bean extract for weight loss because they think it can prevent starch being absorbed by the body.

The Evidence Behind White Bean Extract for Weight Loss

In 2007, Italian scientists performed an experiment to test if white kidney bean extract really worked in practice.

They recruited 60 mildly overweight volunteers. Half of the volunteers were given 445mg of white bean extract per day. They took the tablet before eating their main meal of the day. The other half of the volunteers were given a placebo, an inactive substance.

After 30 days, people taking the white bean extract lost an average of 6.5 pounds, of which 5.5 pounds was pure fat (source).

People taking the placebo lost less than less than a pound, of which less than half was fat.

In 2010, Chinese scientists performed a larger experiment with 101 volunteers. Half took a placebo and half took 1000mg of white kidney bean extract 15 minutes before each meal. Everyone was told to eat exactly as normal.

After 60 days, people taking the placebo lost less than 1 pound, but people taking white bean extract lost more than 4 pounds (source).

More Evidence

A 2012 study of 12 volunteers found that taking white bean extract before eating lowered blood sugar levels and reduced levels of ghrelin, the hunger hormone. Three hours after eating, people taking a placebo were hungry as normal but people who had taken white bean extract felt fuller and had less desire to eat (source).

A 2004 experiment with 50 volunteers found that people taking white bean extract lost more than twice as much weight as people taking a placebo (source).

Glycemic Index

Because white bean extract blocks the digestion of starch into sugar, it effectively lowers the glycemic index (GI) of foods (source).

White Kidney Bean Extract Side Effects

For any supplement that blocks the absorption of carbohydrates, side effects are a very important concern.

When carbohydrates aren’t broken down into glucose and absorbed by the body, they pass into the large intestine and the colon.

The large intestine is naturally filled with bacteria. These bacteria can break down certain types of carbohydrates, and when they do they produce carbon dioxide and methane. When large quantities of these gasses are created in the large intestine, it can causes flatulence and gastrointestinal discomfort. This is what causes lactose intolerance in people with naturally low levels of the enzyme that breaks down lactose, a type of carbohydrate.

However, high quality white bean extract is specifically formulated to avoid these problems. This is one reason that’s it’s extremely important to get white bean extract in the form of the patented “Phase 2®” formulation. Cheaper generic versions of white bean extract may cause much greater levels of gastrointestinal distress.

In 2011, two scientists from California published a review of all clinical evidence on Phase 2 bean extract.

They found that there were no serious white kidney bean extract side effects. They reported that doses up to 3000mg per day were well tolerated. They also reported that a small number of people experienced some temporary gastrointestinal discomfort such as bloating or constipation, but that these symptoms disappeared with continued use of the white bean extract (source).

White kidney bean extract is not recommended for women who are pregnant or nursing. Anyone with an underlying medical condition should talk to their doctor before taking white kidney bean extract.

How to Use White Bean Extract

As we’ve discussed, white kidney extract works by blocking the break down of starch into sugar. That means it’s limited in the following ways:

It can’t block the absorption of fat or protein. White bean extract won’t affect calories from these sources.

It can’t block the absorption of sugar. White bean extract blocks complex carbohydrates. While sugars are carbohydrates, they’re simple carbohydrates. Most sugar you eat is made up of glucose, fructose or sucrose. Glucose and fructose can both be absorbed directly by your body. Sucrose has to be broken down first, but this done by a different enzyme (not amylase). White bean extract won’t block calories from sugar.

Because white bean extract only blocks complex carbohydrates like starch, it’s most effective when taken before eating a meal where most of the calories come from starch. This includes foods like:
  • Pasta (spaghetti, macaroni)
  • Rice
  • Potatoes (chips, french fries, mashed potatoes)
  • Cornmeal (polenta, grits)
  • Wheat and other grains (bread, crackers, pretzels, bagels)
  • Quinoa

Where to Buy White Bean Extract

With any nutritional supplement, it’s important to get a quality product from a trusted source. But it’s particularly important with white bean extract, because the quality of the extracts on the market vary so much and because a poor quality extract can make you feel quite unwell. That’s why knowing where to buy white bean extract is critical.

All of the following recommendations contain genuine Phase 2 white bean extract only.


The best source I’ve found for people living in the USA is Now Foods Phase 2 Starch Blocker sold by Amazon.com


It can be a little tricky to find white bean extract in Canada that isn’t very expensive.

By far the best deal I’ve found is CARB INTERCEPT (Phase 2) sold by Biovea.com. At the time of writing, shipping to Canada is a very reasonable $3.95

UK and Ireland

The best offer I’ve found is Carb Minders with Phase 2  White Bean Extractfrom Holland & Barrett. They ship to both Northern Ireland and the Republic of Ireland.

 White Bean Extract
About John Shade

John is the founder of Supplement SOS. He has written about health and nutrition for a number of high-profile publications. He's particularly interested in the future of sustainable food production and optimizing food products for human health.