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Mag-on review summary: the energy gels pack a robust 120 calories and 30 g of carbohydrates in a 41 g package. The unique feature is 50 mg of magnesium, an essential mineral and electrolyte. The gels’ consistency is on the watery side, and they provide a delightful tart flavor.


Mag-on has been a popular energy gel brand in Japan for many years, and it looks like the secret is out. I see more and more westerners fueling their adventures with this highly effective, energy-packed option.

As arguably the third-best distance running nation, behind Kenya and Ethiopia, Japan’s running scene offers an array of great products not readily available in North America and Europe.

My running friends that closely follow the Japanese running market swear by Mag-on, and I have occasionally used it as well, but I never gave it a thorough test drive.

I purchased some Mag-on energy gels when I was in Japan last month to run the Osaka Marathon. Below is my review after fueling a 20 km easy effort with three Mag-on energy gels.

Marketing claims – all about magnesium

The “Mag” of Mag-on stands for magnesium. Its energy gels provide 50 mg of magnesium per sachet, about 12-15% of the daily recommended intake.

What are the benefits of magnesium?

Before we get to the meat of the review, let’s look at why magnesium is crucial to your overall health and athletic performance. After all, Mag-on’s brand and product strategies revolve entirely around this micro-nutrient.

Magnesium is an essential mineral and also an electrolyte. The human body doesn’t produce it, meaning you can only get it through diet. In case you are curious, there are 16 essential minerals categorized into two groups: major minerals (we need large quantities) and trace minerals (also crucial to our health, but we don’t need nearly as much).

  • Major minerals: calcium, chloride, magnesium, phosphorus, potassium, sodium, and sulfur.
  • Trace minerals: chromium, copper, fluoride, iodine, iron, manganese, molybdenum, selenium, and zinc.


Magnesium is responsible for hundreds of bodily functions, including food-to-energy conversion, protein synthesis, DNA and RNA repair, muscle contraction, bone health, cardiovascular functions, and nervous system regulation, to name a few.

It should be easy to get enough magnesium through the foods we eat. The daily recommended intake is 400-420 mg for men and 310-320 mg for women. Leafy greens, fruits, lentils, nuts, and seeds, are all rich in magnesium.

Yet most people are magnesium deficient. The argument is that the average modern diet doesn’t contain an adequate amount of magnesium. And even people with a well-balanced diet that includes the mentioned magnesium-rich foods don’t get enough either.

Why? Magnesium supplement proponents claim that today’s farm soils are far less fertile, affecting the content of magnesium and other minerals in our foods. Additionally, endurance athletes require higher magnesium intake since we sweat out more electrolytes such as magnesium.


What are the ingredients and nutritional facts of Mag-on energy gels?

I tried three flavors – Lemon, Pink Grapefruit, and AO Mikan (tangerine). They have the same nutritional profile, offering 120 calories, 30 g of carbohydrates, 50 mg of magnesium, and 25 g of caffeine per energy gel.

A few notables:

  • 120 calories and 30 g of carbohydrates are on the high end of the energy content spectrum.
  • A generous dose of magnesium but no sodium and potassium, the two electrolytes more often mentioned in the endurance sports world.
  • Magnesium oxide is not considered a highly bioavailable form of magnesium.
  • Mag-on also offers caffeine-free flavors. I just happened to pick three that have caffeine.
  • AO Mikan offers a few more bells and whistles. It’s fortified with vitamin Bs and C.

Per 41 g pack, it contains:

  • Energy 120kcal
  • Carbohydrate 30 g
  • Protein 0 g
  • Sodium 0 g
  • Fat 0 g
  • Magnesium 50 mg
  • Caffeine 25 mg



Pink Grapefruit

  • Maltodextrin
  • Fructose
  • Grapefruit juice/citric acid
  • Malic acid
  • Natural flavoring
  • Water
  • Magnesium oxide
  • Glycine
  • Caffeine



  • Maltodextrin
  • Fructose
  • Lemon juice/citric acid
  • Malic acid
  • Natural flavoring
  • Water
  • Magnesium oxide
  • Glycine
  • Caffeine


AO Mikan

  • Maltodextrin
  • Fructose
  • Green tangerine juice/citric acid
  • Malic acid
  • Natural flavoring
  • Water
  • Magnesium oxide
  • Glycine
  • Caffeine
  • Niacin
  • Calcium pantothenate
  • Vitamins B6, B1, B2 and C

What are the taste and consistency of Mag-on energy gels?

If you prefer a more watery consistency, Mag-on could be a good option. The brand is well known for providing tart, fruity flavors different from western brands such as GU and SiS.

I find Mag-on energy gels pleasantly light and tart. Lemon was a tat too sour for me, but Pink Grapefruit and AO Mikan were delightful, especially on an unseasonably warm day.

Regarding taste and consistency, I give Mag-on an A.

How’s the packaging of Mag-on energy gels?

The shape of Mag-on is similar to the gels more common in western markets, only slightly larger, about 12 cm long. The longer packaging is justifiable for an energy gel that provides 120 calories and 30 g of carbohydrates.

The opening of the gel, however, is different from anything I’ve ever tried before. The pre-cut tear is located at the “lid” of the bottle-shaped sachet and is in a different color than the rest of the packaging. It’s an easy rip and allows the perfect opening to consume the watery gel. 

Motivational sayings are printed on the front of the sachet. They’re inspiring and amusing at the same time.

“Well done is better than well said.”
“Gray skies are just clouds.”
“After a storm comes a calm.”
“Winners don’t wait for chances. They take them.”
“One finds limits by pushing them.”
“Make yourself stronger than your excuses.”

Wisdom galore!


I tested the three flavors on a 20 km easy run that took 1 hour and 37 minutes. I ran on an empty stomach and ate the gels at the 15-, 40- and 65-minute marks.

Some takeaways:

  1. The tartness of Lemon surprised me. It was the tartest one and gave me mild throat discomfort. The sourness of the other two flavors was more suitable for me.
  2. A shot of 120 calories, 30 g of carbohydrates, and 25 g of caffeine every 20 or so minutes provided quite the boost. I felt energized and focused throughout the run.
  3. The “lid” piece of the sachet is tiny and difficult to keep track of after tearing it off. A big minus.
  4. However, it creates an optimal opening to consume this watery energy gel.
  5. Three caffeine energy gels were too much caffeine for me. I should have picked two other flavors that didn’t contain caffeine. My own damn fault.
  6. Although the sachet is relatively long, it’s not bulky. It’s an energy gel that can fit in any fuel-carrying gear.
  7. Whether the magnesium content made a difference is hard to tell. I personally think it’s just a marketing gimmick. What truly affect performance are calories and sugar, which Mag-on provides in abundance.



Mag-on energy gels contain a robust 120 calories and 30 g of carbohydrates in a 41 g package. The unique feature is 50 mg of magnesium, an essential mineral and electrolyte. The gels’ consistency is on the watery side, and they provide a delightful tart flavor.

We highly recommend this energy gel for longer training runs, marathons, and ultras. The lighter consistency and tart fruitiness make the gels especially suitable for hot and humid conditions. Although the packaging is big, it’s reasonable for a gel that provides that much fuel.

Overall, Mag-on made an excellent fuel for endurance athletics – great flavor and energy packed.