Karbolyn Fuel
EFX Sports

Karbolyn Fuel

High-Performance Carbohydrate Powder for Building Muscle*
Loads Muscle Tissue for Optimum Performance, Endurance, and Recovery*
9.5  out of 10  (153 Reviews)

Product Overview

EFX Sports Karbolyn Fuel. Designed to support Energy*, Endurance* and Recovery*


What is this “Performance Carbohydrate” Karbolyn?

Karbolyn® represents the dawn of a new era of carbohydrate supplementation. Derived from potato, rice and corn, this fast-acting, long-lasting, high-performance compound offers the best of both simple and complex carbohydrates.*

Karbolyn graph

Simple carbohydrates have the ability to enter the bloodstream quickly. However, they can also stimulate a strong “spike” due to a rapid rise and fall of insulin levels. This may be good for a quick burst of energy but not for sustained endurance.*

Complex carbohydrates do provide sustained endurance. But, they are slow to digest, and can leave you feeling bloated and lethargic.*

Karbolyn® Delivers The Best of Both Worlds
Karbolyn® is absorbed into the bloodstream like a simple sugar. It has also been shown to be absorbed as quickly as pure Dextrose (a simple carbohydrate). Yet, it still provides sustained energy.*


The Clinical Study sought to document whether or not Karbolyn® has a positive and sustainable impact on blood sugar levels in normal adults during aerobic activity. Data obtained from participants indicated that a simple sugar promoted a steep drop and subsequent “crash” at a predictable point in time. Karbolyn® gave an overall smoother decline in blood glucose level.*

Karbolyn® Study Data - Re: IRB No : 29443/1; KL-001 - Study: July 2014–March 2015




Ingredients either Pass or Fail...and a 'Fail' is rejected and shipped back.

When you invest in EFX Sports products, you are putting your faith in the efficacy and purity of our ingredients, and the integrity of our brand. That's why we NEVER take that trust for granted.

From dock-to-dock, we own every phase and process to ensure that what's on the label is what's in the bottle...without question.


    To confirm the ID of a given Raw Material and the accuracy of the Certificate of Analysis (COA) we use FTNIR (near infrared technology).
    Vendor COA claims are checked for purity by HPLC, GC or ICP.
  • Heavy Metals
    We test for Arsenic, Cadmium, Lead and Mercury. Heavy Metals must be under the USP specified guidelines.
    We test for Total Plate count, Total Yeast and Mold count and Coliform bacteria to make sure that the Raw Material complies with the USP, AHPA and FDA guidelines.
    Raw Materials are tested for E. coli, Salmonella, and Staphylococcus aureus pathogens (as needed).
  • Drug Screen
    Raw Materials are tested for banned steroidal substances (as needed).


    We perform ATP swab tests prior to batch production and allergen swab tests as needed to ensure equipment is free of potential contamination or microbes.
    We use FTNIR to confirm the ID of a given in-process mix to ensure it contains the correct raw ingredients.
    Purity is checked by using HPLC, GC, and/or ICP to ensure the in-process mix will create a final product that meets label claims.


    We use FTNIR to confirm the ID of a Finished Product.
  • Purity (label claim)
    We check the purity by HPLC, GC, and/or ICP if there is a label claim on the Finished Product COA.
    We test for Total plate count, Total Yeast and Mold count and Coliform bacteria to make sure that the Finished Product complies with specifications.
    We test again for the following pathogens, E. coli, Salmonella, and Staphylococcus aureus (as needed).
    We list the allergens, if present in the Finished Product.
    We test the Finished Product for Heavy Metals contaminants (Arsenic, Cadmium, Lead and Mercury) and make sure they are under the USP specified guidelines.
    We use an outside 3rd party laboratory to conduct GC-MS/ HPLC-MS testing on finished products for banned steroidal substances, if needed.

Ratings & Reviews

Karbolyn Fuel
Overall Rating
153 Ratings
Verified Buyer Rating
81 Ratings
Average Flavor Rating
10 Flavors
Top Rated Flavor
Kiwi Strawberry
By clicking the button above, you agree to entering the Bodybuilding.com Reviews section. Products in the Store are not intended to diagnose, treat, cure, or prevent any disease.
May 15, 2020
Verified Buyer
  • 10 Neutral Flavor

I am absolutely in love with this product and it’s become a staple that I HAVE TO HAVE. I use it post workout and when carb loading for competition, but the best part is that the container comes completely filled to the top!!!! There is NO space between the seaL and the powder and they actually give the full amount, unlike some brands that only fill their containers 3/4ths of the way full which is a disappointment. Super happy with this brand and product.

May 31, 2019
Verified Buyer
  • 10 Blue Razz Watermelon

This is a great endurance supplement. I sip on Karbolyn throughout my power lifting competition flights to keep my energy level up. I only started using this product 4 months ago and have competed twice since and I am very satisfied.

Dec 06, 2018
  • 10 Strawberry

Great taste and noticeable pump when sipping during workout. Easy on the stomach.

Oct 18, 2018
Verified Buyer
  • 10 Cherry Limeade

The pumps and endurance are insane. Allows me to destroy arms even after a massive chest pump.

Sep 08, 2018
Verified Buyer
  • 10 Blue Razz Watermelon
  • 10 Cherry Limeade
  • 8 Fruit Punch
  • 10 Kiwi Strawberry
  • 7 Neutral Flavor

The neutral flavor is fine although it gets very clumpy compared to the other ones.

Jul 03, 2018
Verified Buyer
  • 9 Cherry Limeade

I would give this product a 10/10 if it wasn’t so sweet. It’s borderline insane to taste how sugary this stuff is, but it really does work! I shifted my workout routine from evenings to early morning several months ago and found that I just couldn’t lift as heavy in the mornings even after having a quick breakfast before hitting the gym. I learned this was due to low glycogen levels in the morning since it had been 8+ hours since my last meal. So I started drinking this mixed with caffeine when I first wake up (approx 30 min before workout) and it truly makes a difference. My strength is returning and endurance and intensity it back! Love how well it works. Hate how sweet it is.

Mar 15, 2018
  • 9 Cherry Limeade
Sep 27, 2017
Verified Buyer
  • 10 Cherry Limeade

This Product is fantastic! I train Heavy and Hard everyday. Carb replacement is very important to me. Its Critical! Ive tried many different Carb supplements without much success until KARBOLYN. It replenishes my glycogen. I get a fantastic pump. My muscles stay full and hard. I have plenty of energy after training. It doesn't upset my stomach and it tastes great. Highly Recommend!!

May 31, 2017
  • 10 Neutral Flavor
  • 9 Strawberry

Use: Protein + Karbolyn Before and After workouts Taste and Mixing: Amazing! Mix Orange or Strawberry with vanilla protein and it smooth and creamy “Orange Cream-Sicle”. The Neutral flavor is easily covered by any flavor no weird taste. If you let is sit for 5 to 10 mins it can “clump up” but it just settled, a quick shake “redistributes” it very easy. The clumping is not a mess of gu that can’t mix. This mixes easy from the start with any protein or BCAA I’ve use so far. The BreakDown Three days a week I am up at 5:00am straight to the kitchen for my shake (Protein + Karboltn) then in the gym by 6:15 to 6:30 and 50 mins of that is letting my pup out, driving, and walking to get to the gym. Needless to say I don’t have spare time in the morning. This shake fuels me through a 2 hour workout. (I normally only workout for and hour on these days in the morning) On the other four days a week I’m in the gym for an afternoon for at least 2 hours (Weight lifting and Cardio) and I never hit a wall. (keep in mind I am also using BCAA during this workout) I have used this for bulking, cutting and maintaining and it’s never failed to help promote energy throughout all my workouts. I have recently in addition to per and post started mixing this with my BCAA during and LOVE it! Seeing lot of progress over the last month of doing this. I feel at 100% on every exercise on every set! Supplements don’t make great workouts, they just help maximize the work you put in!

Feb 19, 2017
Verified Buyer
  • 7 Neutral Flavor

I mix Karbolyn with my morning shake. Nutrabio Java Whey (1 scoop), Nutrabio Chocolate Isolate (1 scoop), and Karbolyn (1 scoop). It is a good clean carb with no sugar (unlike most carbs). Another must have in the weight lifters arsenal from EFX. The neutral flavor adds a little bit of a different taste to the protein shake, but i have gotten used to it.

Feb 16, 2017
Verified Buyer
  • 8 Neutral Flavor

This product did have a neutral taste. I rated this product a 6 mainly due to its poor mixability. About 90% of it would mix but always someone leaving a small lump that would taste horrible when you get to it. I will be going back to Carbion from Allmax.

Dec 30, 2016
Verified Buyer

This product is great! I've used Karbolyn for over two years now. What bothers me is the fact that the packaging changes without any notice, and in many cases, small adjustments are made to the nutritional composition of the product too. Considering many of those who take it count their calories and macros and pay close attention to what they consume, I don't find that okay with regards to loyal customers- not in the health and fitness industry!

Dec 25, 2016
Verified Buyer
  • 9 Blue Razz Watermelon

Since MusclePharm is reformulating their Recon which was my go-to. I had to find another source and this came to mind. If you are looking for a great taste, slushy like consistency with no crash, than give this a try. I was impressed!

Oct 15, 2016
Verified Buyer
  • 10 Blue Razz Watermelon

I am new to carb supplements, and this was recommended to me by my sister and coach. I LOVE IT! The flavor is AMAZING, and it mixes nicely, even without a blender ball or anything, you can just shake it up in a bottle with water, and you're good. The only thing I don't love about this product is the fact that it starts to settle a bit if you don't drink it fast enough. But it's no biggie, you can just shake it back up and you're back in business!

Sep 25, 2016
Verified Buyer
  • 7 Blue Razz Watermelon

I chose this flavor because it was very well reviewed but I didn't think it was anything great. Not bad but not that good either. The product works great though! I had to switch to a different intraworkout carb source since Glycofuse has been giving me tons of GI distress over the past 6 months (I had used it for 3-4 years with no problems). No GI distress with Karbolyn! I highly recommend this product but not this flavor in particular. I will be buying more Karbolyn soon.

4 Sizes
2.2 Lbs.
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4 Flavors
Blue Razz Watermelon
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Everyday Low Price
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Price: $29.99  ($1.67 / Serving)
Flavor Rating: 9.6


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Loads Muscle Tissue for Optimum Performance, Endurance, and Recovery*

What's in EFX Sports Karbolyn Fuel

2.2 Lbs. Blue Razz Watermelon
Serving Size 53g (One Scoop)
Servings Per Container18
Amount Per Serving % Daily Value
Calories 200       
Calories From Fat 0       
Total Fat 0 g 0%
Saturated Fat 0 g 0%
Cholesterol 0 g 0%
Sodium 0 g 0%
Total Carbohydrates 50 g 16.7%**
Dietary Fiber 0 g 0%
Sugars 0 g
Protein 0 g 0%
Karbolyn® 50 g
(homopolysaccharide derived from potato, rice and corn)       
** Percent Daily Values are based on a 2,000 calorie diet.
† Daily Value (DV) not established
Other Ingredients:
Citric Acid, Sucralose, Natural & Artificial Blue Raspberry, Watermelon, & Vanilla Flavors, and FD&C Blue #1

Directions For Karbolyn Fuel:

Suggested Use for Individuals

As a dietary supplement, mix 1 scoop in a shaker cup with 16 oz of water and drink 30 minutes before exercise.

Usage Guidlines for Intense Training or Athletic Events

BEFORE TRAINING - Drink 1 serving 30 minutes before exercise.

DURING TRAINING - Sip on 1 serving during exercise.

AFTER TRAINING - Drink 1 serving after exercise.

Warnings: Keep out of the reach of children. STORAGE: Protect from heat, light and moisture. Store at 59-86°F (15-30°C)

* These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Learn more about Carbohydrates.
Check out other Performance Products.