Anti-Fatigue Caps


(3+ FOR $19.99 EACH)

Rated 4.92 out of 5 stars
of respondents would recommend this to a friend
Eliminate endurance barriers
  • Prolongs endurance
  • Speeds endurance
  • Eliminates “heavy legs”


Anti-Fatigue Caps is truly a “there’s nothing else like it anywhere” supplement, one that greatly extends endurance by effectively neutralizing the fatigue-causing effects of ammonia build-up, often referred to as “the endurance athlete’s worst enemy.” Three well-known ammonia-scavenging compounds make up this unique formula, helping to prevent the dreaded “heavy” legs sensation and extend energy output.

2-4 capsules one hour prior to training. This would provide an initial dose of 500-1000 mg magnesium/potassium aspartate, and 480-960 mg of OKG, an excellent dose at the onset of an endurance workout or race.

An additional 1-2 capsules each hour, at the two-hour mark and beyond, during extended endurance sessions is also suggested.

Ingredient Breakdown:

Potassium/Magnesium Aspartate – This compound is comprised of potassium and magnesium chelated (aka “bonded”) to the amino acid aspartic acid. It often used for alleviating general fatigue and is sometimes involved in treatment regimens for Chronic Fatigue Syndrome.

L-Citrulline – This amino acid is found in foods such as watermelon, onions, and garlic. L-citrulline assists in the removal of ammonia in the muscles and liver. Like aspartic acid, it is beneficial in alleviating fatigue.

OKG (Ornithine Alpha-Ketoglutarate) – A combination of the amino acid L-ornithine and the compound alpha-ketoglutarate. OKG provides a readily available, non-ammonia-producing source of glutamine in the body. Both L-ornithine and alpha-ketoglutarate act as ammonia scavengers in the body.

Beet Juice Powder – While the primary function of this ingredient is coloring the capsules to easily differentiate them from similar-looking capsules such as Endurolytes, beetroot powder also boosts nitric oxide levels.

Anti-Fatigue Caps
Supplement Facts
Serving Size: 4 Capsules
Servings Per Container: 22
Amount Per Serving% Daily Value*
Potassium Magnesium Aspartate1000mg
Magnesium (as magnesium aspartate)100mg12%
Potassium (as potassium aspartate)140mg2%
OKG (Ornithine alpha-ketoglutarate)700mg
L-citrulline 700mg
* The Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.
† Daily Value not established.
Other Ingredients: Beet Juice Powder, Stabilized Rice Bran, Vegetable Capsules (plant cellulose and water)

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.
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Important Part of My Training
Great product! Anti-Fatigue really works!
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Review Snapshot

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Rated 4.92 out of 5 stars
107 ReviewsWrite a Review
of respondents would recommend this to a friend

Ratings Distribution

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Reviewed by 107 customers

Very Big Difference

Rated 5 out of 5 stars

I decided to finally try anti fatigue caps even though I'm a very skeptical person. I'm suprised by just how big of a difference they make. At the end of my long run I found that I was still hopping across rocks and my legs felt lighter than they ever have after that length of running.

Bottom Line Yes, I would recommend to a friend

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I would buy and reccomend this product

Rated 5 out of 5 stars

These are the "go to" before, during, and after training sessions or races! I started using these two weeks ago, and I can feel my legs are able to take on more without getting heavy as they did before. I will continue to use them as part of my daily and race kit! Thanks Hammer Nutrition!! Redemption Running and Fitness

Great results

Rated 5 out of 5 stars

Use before Paddleboarding,surfing and cycling

Merchant Response

Hi there, thanks for the kind words, we appreciate you taking the time!

Repeating purchase, years now

Rated 5 out of 5 stars

Like it's named & very beneficial

Merchant Response

Hi Ricky, keep those miles up and we'll be right there with ya!

Always the best!!

Rated 5 out of 5 stars

It's been part of my and my athletes arsenal for years!

Merchant Response

Hello Enrique, keep those Anti-Fatigue caps going for many more years!


Showing 10 out of 18 Questions


What is the difference between anti-fatigue caps and Endurance BCAA plus?

Asked by Chris
Verified Reply - SteveThe primary difference between the two products is that Endurance BCAA+ protects against lean muscle tissue breakdown and the excess ammonia that is produced, and Anti-Fatigue Caps addresses the negative effects of ammonia that is already produced and accumulating, by scavenging it into much less harmful substances for excretion via the urea cycle. This combination is outstanding for extending endurance! ANTI-FATIGUE CAPS ( – This product supplies three nutrients—potassium/magnesium aspartate, l-citrulline, and OKG—that help neutralize the negative effects of excess ammonia, a primary culprit in premature fatigue. • Potassium/Magnesium Aspartate - A well-known nutritionist says it best regarding aspartic acid, "Because aspartic acid increases stamina, it is good for fatigue and plays a vital role in metabolism. It is good for athletes and helps to protect the liver by aiding in the removal of excess ammonia." Studies (Agersborg and Shaw 1962, Hicks 1964, Gaby 1982) show this combination provides substantial benefit for the prevention of fatigue. Aspartic acid also combines with other amino acids to form molecules that absorb toxins and remove them from the bloodstream, aids the function of RNA and DNA, and helps to protect the liver. Additionally, the potassium/magnesium aspartate compound increases production of a key substrate, oxaloacetate, which is involved in energy production. Lastly, the compound provides the minerals potassium and magnesium to help provide protection against cramping. • L-Citrulline – L-Citrulline is an amino acid that is found plant foods such as watermelon, onions, and garlic. Citrulline helps in the removal of ammonia in the muscles and liver, and, like aspartic acid, is beneficial in alleviating fatigue. L-citrulline is a precursor for the endogenous production of l-arginine. Increased blood levels of arginine significantly boost nitric oxide (NO) content. NO acts as a potent vasodilator, relaxing the arteries, and allowing them to widen. Vasodilation is responsible for increased blood flow to tissues such as muscle fibers, which supports enhanced athletic performance and cardiovascular health. • OKG - Both ornithine and alpha-ketoglutarate (OKG) provide a readily available, non-ammonia-producing source of glutamine in the body. Glutamine is depleted at high rates during exercise but cannot be replaced with regular glutamine as it produces ammonia on its own. OKG increases the amount of glutamine in the muscle and also helps prevent muscle catabolism. Colgan writes, "Both ornithine and alpha-ketoglutarate act in the body as an ammonia scavenger." Suggested Dosing: 2-4 capsules 20-30 minutes prior to exercise, with additional doses of 1-2 capsules every hour. ENDURANCE BCAA+ ( – This product supplies the key amino acids—the BCAAs (leucine, isoleucine, valine)—that the body needs to satisfy a small percentage of its energy requirements during prolonged bouts of exercise, helping to protect against lean muscle tissue breakdown. BCAA supplementation has also been shown to decrease the perception of fatigue on both a mental and physiological basis. Two capsules contain: • L-Leucine – 400 mg • L-Isoleucine – 200 mg • L-Valine – 200 mg Endurance BCAA+ also contains (per 2 capsules) • L-Alanine – 100 mg The liver can convert L-alanine into glucose as needed, which the bloodstream transports to the muscles for energy. L-alanine also aids in the synthesis of pantothenic acid (B-5), which is also needed for protein, fat, and carbohydrate metabolism. activation in cells. L-alanine also activates an enzyme called AMPK that turns on genes that serve to increase energy production. • Reduced Glutathione – 100 mg Glutathione is a tripeptide, consisting of the amino acids glutamic acid, cysteine, and glycine. It is one of the three endogenous (naturally occurring in the body) antioxidants the body maintains to control excess exposure to free radicals produced during exercise as well as from exposure from the environment. Literally pages and pages could be written about this tremendously powerful nutrient, which one nutritional scientist calls glutathione “The Life-Extending Master Antioxidant,” with an Oxygen Radical Absorbency Capacity (ORAC) score/rating estimated to be an astounding 12,000+, glutathione is undoubtedly a potent antioxidant, arguably the most important one in existence. Suggested Dosing: Exactly the same as Anti-Fatigue Caps. May take 2 capsules after exercise for recovery purposes.

The antifatigue capsules that i bought has turned darker brown in color but is not expired yet, can i still use it?

Asked by cynthia
Verified Reply - SteveThe darker brown suggests that there may have been slight exposure to air, heat, humidity, or all three. Unless there are distinct large melty-looking spots on or inside the capsule, the product is fine to use.

Is the Anti Fatigue vegan?

Asked by Cindy
Verified Reply - SteveYes, Anti-Fatigue Caps are 100% vegan friendly

Any issues with patients with heart condition in general? Thank you.

Asked by Sivabalan
Verified Reply - SteveWhenever one has a medical condition, it's always best to discuss the use of any supplement with the physician prior to using it. This is especially true if the person is on a prescription medication. That said, all of the nutrients in Anti-Fatigue Caps can be considered "heart healthy" nutrients. This includes the potassium and magnesium that occur in the potassium/magnesium aspartate compound. L-citrulline, in addition to reduce ammonia, is an excellent nitric oxide booster, which helps the arteries relax for better blood flow. OKG (ornithine alpha ketoglutaric acid) is oftentimes given to patients after surgery or stroke to help with the muscle rebuilding process.

Is this safe to give to my son who is a teenager.

Asked by Nancy
Verified Reply - SteveAnti-Fatigue Caps are completely acceptable for teenage athletes to use.

I have a bottle of Anti fatigue caps which states there "mfg: 10/2016. It doesn't state down the expiry date of use. Can I still consume these caps? It's already Oct 2018

Asked by Kenny
Verified Reply - SteveStored properly--away from direct sunlight, moisture, and excess heat--all Hammer Nutrition supplements, including Anti-Fatigue Caps, have a "best by" date that extends four (4) years from the manufacture (MFG) date. You've still got two (2) full years of use from your bottle of Anti-Fatigue Caps!

Can I add a salt capsule to this and still take gu gels? For marathon?

Asked by Trin
Verified Reply - SteveAnti-Fatigue Caps contain a small amount of potassium and magnesium, courtesy of the potassium/magnesium aspartate compound that is in the product. This compound is in Anti-Fatigue Caps--along with the l-citrulline and OKG components--to negate the negative, fatigue-causing effects of ammonia build up. These two minerals are also necessary electrolytes and the amounts you receive in a 2-capsule dose of Anti-Fatigue Caps will complement the amounts found in Endurolytes (, Hammer Nutrition's full-spectrum electrolyte product. Anti-Fatigue Caps is completely complementary with Hammer Gel as well.

Is there a maximum dosage over a period of a day? I will be running a 100 miler that could take 24-26 hours and certainly don't want to take too many!

Asked by MARunner
Verified Reply - SteveAt the rate of 1-2 capsules per hour, there are absolutely no issues with taking too many Anti-Fatigue Caps, even over the course of a 24+ hour event. Remember that your body will be using these nutrients once they're ingested, so there is no "build up" kind of effect... all you're doing by taking hourly doses during your race is replenishing your body with these nutrients, which have been used and thus depleted over the course on an hour. Athletes competing in the Race Across America--a 9-12 day race--have used this product on an hourly basis for several days! No issues whatsoever.

Can I take these with an endurance drink containing magnesium and potassium?

Asked by Kerri
Verified Reply - SteveYou can absolutely take Anti-Fatigue Caps with a sports drink or electrolyte supplement. Every capsule of Anti-Fatigue Caps contains 250 mg of a compound known as potassium/magnesium aspartate. The majority of this compound is the amino acid, aspartic acid (a.k.a. aspartate). Regarding this amino acid, Dr. James Balch states “Because aspartic acid increases stamina, it is good for fatigue and plays a vital role in metabolism. It is good for athletes and helps to protect the liver by aiding in the removal of excess ammonia." The remaining components in the compound are magnesium (25 mg) and potassium (35 mg). The amounts of these two minerals will complement the amounts provided in an electrolyte supplement (one of the Endurolytes products) or a sports drink (Hammer Nutrition's HEED).

Is it possible to use Hammer anti/fatigue to combat fatigue on a daily basis? If not anti-fatigue, could you recommend another Hammer product ? Thank you

Asked by Patty
Verified Reply - SteveGreat question! The answer is "YES!" You can se Anti-Fatigue Caps on a daily basis to help alleviate everyday fatigue. Many of the staff at Hammer Nutrition take 1-2 capsules after lunch to help alleviate fatigue (the dreaded "3 O'clock Fade"), and with no stimulant effect whatsoever. The main component in the product is Potassium/Magnesium Aspartate, which is commonly recommended by holistic practitioners for their clients who deal with fatigue issues.