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Amino Saurus, a sports nutrition maker based in Japan, offers a simple energy gel portfolio with only two flavors: mango and lemon. However, their ingredients are anything but ordinary.

Unlike some brands that focus on providing the essentials and removing unnecessary additives, Amino Saurus energy gels went the other way, including “fancy” ingredients and concepts that are rarely seen. In this review, we share our experiences fueling a four-hour long slow distance (LSD) run with Amino Saurus energy gels.

Although Runivore is a website mainly focused on the Western market, we take pride in finding interesting sports nutrition products from all over the world. We have recently reviewed other energy gels and energy gel alternatives from Japan.

What are Amino Saurus energy gels?

Here are a few interesting points we noticed from the product website:

  1. 2000 mg of citric acid: While many energy gels contain citric acid, Amino Saurus is the first brand we’ve seen that specifically highlights it. Citric acid is a naturally occurring compound in fruits and can also be synthesized artificially. It’s unclear whether Amino Saurus uses organic or synthetic citric acid. Possible benefits include enhancing nutrient bioavailability, energy metabolism, and providing a tart flavor as a food additive.
  2. The mango flavor contains caffeine, while the lemon flavor includes BCAAs (branched-chain amino acids). The rest of the ingredients are very similar.
  3. A hefty dose of magnesium.
  4. Amino acids arginine and citrulline are included.
  5. Both flavors contain close to 6 g of protein.
  6. Possibly more fructose than glucose.


Let’s dive into the ingredients in the following sections.

What are the ingredients and nutrition facts of Amino Saurus energy gels?

Mango flavor ingredients and nutrition facts:

Fructose, maltodextrin, citrulline, agar, anserine-containing fish peptide/acidulant, arginine, magnesium chloride, flavoring, caffeine.

  • 45 g
  • 123.3 calories
  • Protein: 5.8 g
  • Fat: 0 g
  • Carbs: 25 g
  • Salt equivalent: 0.1 g (38.8 mg of sodium)
  • Arginine: 2000 mg
  • Citrulline: 1000 mg
  • Magnesium: 50 mg
  • Citric acid: 2000 mg
  • Caffeine: 75 mg

Lemon flavor ingredients and nutrition facts:

Fructose, maltodextrin, citrulline, agar, anserine-containing fish peptide/acidulant, arginine, magnesium chloride, leucine, isoleucine, valine, flavoring.

  • 45 g
  • 111.6 calories
  • Protein: 5.9 g
  • Fat: 0 g
  • Carbs: 22.1 g
  • Salt equivalent: 0.1 g (38.8 mg of sodium)
  • Arginine: 2000 mg
  • Citrulline: 1000 mg
  • BCAA: 500 mg
  • Magnesium: 50 mg
  1. Fructose is listed before maltodextrin, indicating that the energy gels contain more fructose than glucose, which is highly unusual. Most of the energy gels we’ve tested follow a 2:1 or 1:0.8 glucose-to-fructose ratio. This doesn’t make sense to me since scientific evidence points to “glucose > fructose,” and fructose is known to be harmful to people with sedentary lifestyles.
  2. The 5+ g of protein content is high compared with other energy gels. Research studies have suggested that proteins require the human body to divert more blood to the digestive tract to process, which means less oxygen for muscles when you’re on the move and increases the risk of stomach stress.
  3. The 50 mg of magnesium is about 12-16% of the recommended daily intake. That’s a significant amount of this important electrolyte.
  4. Arginine and citrulline are two amino acids that may benefit athletic performance, but results from scientific studies have been mixed. These two ingredients are also rarely found in energy gels.
  5. The mango flavor contains caffeine, while the lemon flavor has branched-chain amino acids (BCAA) – leucine, isoleucine, and valine – which have shown to aid in delaying muscle fatigue.


What are the tastes and consistency of Amino Saurus energy gels?

Amino Saurus energy gels are sour, possibly due to the high citric acid content. The two flavors are indistinguishable, especially when you’re working hard during a session. If you enjoy tart flavors, this brand should be a suitable option for you.

The consistency of the gels falls somewhere in the middle of the spectrum. Overall, I found Amino Saurus energy gels palatable.

How’s the Packaging of Amino Saurus energy gels?

The packaging of Amino Saurus energy gels is long at 14 cm, which is understandable given the above-average weight (45 g), carbohydrate content (22-25 g), and calorie count (111-124).

However, the packet itself isn’t bulky, so the gels should fit in most fuel-carrying gear such as compression belts, shorts pockets, and different compartments of hydration packs.

The tear is located at the very top of the sachet, and it’s best to rip it open with your teeth. Be careful not to lose track of the tiny ripped piece of litter. The opening is also small, requiring more “sucking” and “squeezing” to consume.

One interesting thing to note is that the mango flavor has “1” printed on the sachet, while the lemon flavor has “2” printed on it.

The brand doesn’t explicitly state this, but there is speculation that the two flavors might be best used in tandem – mango for the first half of endurance races (caffeine provides a boost early in the morning), and lemon for finishing strong in the second half (BCAAs delay muscle fatigue and ease muscle soreness).

Are Amino Saurus energy gels effective?

I tested four Amino Saurus energy gels (two of each flavor) during a four-hour LSD run on an undulating route. I had a light breakfast of fruits (kiwi fruits and apples) pre-run.

Here are my takeaways:

  1. Despite the unusual ingredients and concepts such as high protein content, more fructose than glucose, and the arginine and citrulline blend, the energy gels were effective, and I didn’t notice anything out of the ordinary, neither good nor bad.
  2. Each time I took an energy gel, I felt a steady surge of energy. The mouth-to-muscle time was around five minutes.
  3. The energy gels have a tart kick. This is subjective, but I would recommend having water on hand to chase them down.
  4. I experienced no stomach issues. Often times, when I take an energy gel, especially after running for a few hours, my stomach might grumble a bit before settling down. These gels set well.
  5. Since the energy gels only provide 38 mg of sodium, it’s important to have other sports nutrition options to replenish sodium on longer runs and in high temperatures.


Conclusion – Not sure about the fanciness, but it worked well

I believe that carbohydrates, water, and electrolytes are the three most important elements of mid-run fueling. Everything else is either overhyped, just marketing gimmicks, or the benefits are so subtle that they’re unlikely to make a difference.

While I’m not sure about the amino acid blend or the high protein content, Amino Saurus energy gels sustained my energy levels and caused zero stomach stress. The taste wasn’t exactly to my liking, but it’s palatable. Fans of tart fruity flavors will probably enjoy them.

At about USD 2.46 per gel, it’s on the higher end but certainly not outrageously priced. I’m comfortable recommending Amino Saurus.