The 4 Best Carbohydrate Blocker Supplements

When it comes to buying the best carbohydrate blocker supplements, you’ve got a lot of options to choose from, as is the case with many supplements. On top of that, it’s often not clear what’s effective and what brands you can trust.

As a result, it’s easy to get bogged down and frustrated with the volume of options you have. Having options to choose from is great, but too many and it can create a kind of paralysis.

That’s why for this article we’ve done the research to narrow down the best carbohydrate blocker supplements to choose from so that it’s easier for you to pick the one best suited to your needs.

But first, before we get into our picks for the best carb blocker supplements, you may be wondering “what are carbohydrate blockers?”, “how do they work?”, and “are they effective?”.


What are Carbohydrate Blockers and How Do They Work?

Carbohydrate blockers are naturally-occurring compounds that block the enzymes responsible for digesting carbohydrates. These compounds are extracted from foods, usually beans.

They’re also referred to as starch blockers because they block starch as well.

It’s estimated that carb blockers block 50%-65% of carbs that enter the body. (1) If you’re trying to lose weight by taking a carb blocker, you might be wondering, “why don’t they block 100%?” Well, it’s actually good that they don’t, because the body needs at least some carbohydrates to function.


Are Carbohydrate Blockers Effective for Weight Loss?

According to many a supplement company, their carbohydrate blockers are magic bullets that will help you lose a ton of weight all while eating a bunch of garbage food. Well, if you’re a savvy consumer, you probably already know that no weight loss supplement can replace a healthy diet and exercise.

However, even when an industry exaggerates in their marketing, it doesn’t mean we should dismiss a supplement outright before investigating.

When it comes to carbohydrate blockers, we do have some studies to base our decision on.

In one randomized, double-blinded, placebo-controlled study, 60 slightly overweight volunteers were given either a carbohydrate blocker or placebo over a 30-day period. The study participants were physically measured in multiple ways and researchers found that the carbohydrate blocker group “had significantly greater reduction of body weight, BMI, fat mass, adipose tissue thickness, and waist/hip/thigh circumferences while maintaining lean body mass compared to subjects receiving placebo.” (2)

In another study done in 60 overweight subjects supplementation with a carbohydrate blocker was associated with body weight reduction. Feelings of fullness and appetite improved in the group that received the supplement. Researchers did not observe any side effects. (3)

So not only is there evidence that carbohydrate blockers could encourage weight loss by blocking carbs, but also by suppressing the appetite.

Another study that was conducted over a 12-week period concluded that a carbohydrate blocker “is safe and effective for weight loss and maintenance.” (4)

There needs to be more scientific studies on carbohydrate blockers, how they work, and their effectiveness, but as you can see, carbohydrate supplementation is a promising area of dietary research.


Types of Carbohydrate Blockers

There are two main types of carbohydrate blockers:

  1. White kidney bean extract (also referred to as Phaseolus vulgaris extract) and
  2. Alpha-glucosidase inhibitors (AGIs)

Both of these substances work by blocking the enzymes used to digest carbohydrates.

AGIs are prescription medications used to treat high blood sugar in people with diabetes, so for this review, we’ll just be talking about the more natural over-the-counter supplement, white kidney bean extract.

Now that we’ve established what carbohydrate blockers are, here are our picks for the best carbohydrate blocker supplements:


#1: Arazo Nutrition White Kidney Bean Carb Blocker

Image of Arazo Nutrition's White Kidney Bean Carb Blocker Supplement

Arazo Nutrition’s White Kidney Bean Carb Blocker is an excellent choice as far as carbohydrate blockers go.

Its serving size is just one (vegetable) capsule, which contains 600 mg of white kidney bean extract. That’s a nice, potent dose of Phaseolus vulgaris, plenty to achieve its carbohydrate blocker effect. It has 60 capsules, so that’s a two-month supply.

This product is made in an FDA, GMP certified manufacturing facility in the USA.


  • Has close to the ideal amount of white kidney bean extract
  • Comes in a vegetarian capsule
  • Made in a GMP certified facility
  • Fair price
  • Great customer service


  • The instructions on the bottle differ from what Arazo Nutrition has published on Amazon and elsewhere. We’re assuming the bottle is correct (1 capsule per day).
  • Some consumers report that it makes them feel tired

Active Ingredient Quality:


Average Consumer Rating:


#2: Phytoral Non-GMO White Kidney Bean

Image of a bottle of Phytoral White Kidney Bean Supplement

We found that Phytoral’s Non-GMO White Kidney Bean supplement is another valid choice when it comes to carbohydrate blockers.

This supplement is very similar to our number one pick, but with a couple minor differences.

Per pill, it has the same amount of white kidney bean extract (600 mg), but the recommended serving size is two pills, which is twice as much. White kidney bean extract has not been known to be toxic at higher doses, but after 600 mg we think it’s likely many people will see diminishing returns on its effectiveness. The higher dose may be better for people with higher body weight though.

Another difference between the two is the price. Phytoral’s product is a few dollars cheaper per bottle, but if you go by the recommended dosage then you’re going to be paying almost twice as much per pill effectively.

A bottle of this product contains 30 servings. This product is also made with a vegetable capsule.


  • Contains a high dosage, which may be more effective for some people
  • Comes in a veggie capsule


  • Price is high for what you get compared to other products on the market
  • Can cause gas, stomach pain, and diarrhea in some

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#3: Natrol White Kidney Bean Carb Intercept Capsules

Image of a box of Natrol Carb Intercept With Phase 2

Natrol’s White Kidney Bean Carb Intercept Capsules supplement is a good option if you want the health benefits of white kidney bean extract plus a little more.

This product contains a proprietary blend formulated by Natrol that they call their ‘Phase 2 Carb Controller® Complex’. This blend is made of 1,000 mg of white kidney bean extract, Foodbound® chromium, and dibasic calcium phosphate.

Chromium is an ingredient included in supplements to improve nutrient absorption. However, we’d like to see less than 115% daily value in this supplement because you also naturally get some in your diet from food.

This supplement comes in pill form (veggie capsules), which is good, but unfortunately, it does have some binders and fillers.

It does not contain fish, eggs, shellfish, peanuts, tree nuts, wheat, sugar, preservatives, or artificial colors/flavors. However, it does contain milk and soy.

It comes with 120 capsules, which is a 60-day supply.


  • Helps control your carb intake
  • Consumers have been using it along with a keto diet to great effect


  • Causes painful gas in some
  • Can cause bloating
  • It’s unclear as to how much white kidney bean extract is in this product

Active Ingredient Quality:


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#4 Best Non-Pill Form Carb Blocker: NutraTech Orlistol BlockerDrops

Image of a bottle of NutraTech Orlistol BlockerDrops

Not everyone likes or is even able to take pills, so we like to include alternatives when we can.

As the name implies, this NutraTech Orlistol BlockerDrops supplement comes in the form of drops that you drop under your tongue.

The serving size for NutraTech’s Orlistol BlockerDrops is one dropper, and the bottle contains 60, so that comes out to be a two-month supply.

Each serving consists of 400 mg of a proprietary formula of chitosan, phaseolus vulgaris, apple cider vinegar powder, garcinia cambogia extract, g. sylvestre, aloe vera extract, and California buckhorn.

NutraTech’s goal with this formula was to block not just carbohydrates, but fat as well.

They make a good point in their marketing material in that a carbohydrate blocker like this is great for cheat meals; if you have a “cheat day” where you stray off your normal healthy diet, this can limit the damage.

NutraTech states that “Orlistol BlockerDrops can help you lose an extra 1 pound for every two pounds that you lose through dieting alone.” Remember how we were talking about marketing hype earlier in the article? Not to say that this product is ineffective, but that’s a very bold claim and not something that we saw reflected in our testing even though we did see some weight loss results from using it.


  • Comes in dropper form which is good for those who don’t like taking pills
  • Helps curb feelings of hunger


  • Some say it acts as a laxative for them
  • Doesn’t have the best taste

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So there you have it, the four best carbohydrate blocker supplements on the market as of now. Each of these white kidney bean extract supplements has their own positive aspects, but we think Arazo Nutrition’s White Kidney Bean Carb Blocker is going to be the most effective/cost effective carb blocker supplement for the vast majority of people.

There are plenty of other carb blocker supplements out on the market, some of which are probably high quality, but the four listed here stood out because of good brand reputation, smart formulas, reasonable price, and great overall consumer satisfaction.

Have experience with any of the products on our list? Let us know in the comments section.


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