Do G Fuel Cans Actually Work? (Honest Review)

G Fuel is known for its many variants of energy drinks made to fit all types of drinkers. That’s why they remain to be one of the most popular brands not only among athletes but in the gaming community as well.

Currently, G Fuel offers products for those needing a coffee substitute especially drinkers who are diagnosed with specific diseases. They have the G Fuel Hydration formula, energy crystals, and shaker cups for your drinks!

Given these number of options, does G Fuel actually work as advertised?

G Fuel Can
G Fuel Rainbow Sherbet flavor

One serving of G Fuel can provides 300mg of caffeine or about two cups of coffee, which more than enough to fuel your day. With this amount of caffeine, plus other ingredients for brain functions, you’re all set for any kind of activity your way.

But how does this work? And does G Fuel have side effects?

Before I answer these questions, let’s look into its nutritional facts first.

G Fuel Can Nutrition Facts

Nutrient Amount per Serving (16 fl.oz)
Calories 0
Total Carbohydrates0g
Protein 0g
Potassium85mg (2%)
Niacin (Vitamin B3)4mg (25%)
Vitamin B6.04mg (25%)
Vitamin B12.06mcg (25%)
Vitamin C45mg (50%)
Caffeine 300mg 
G Fuel Can Nutrition Facts

How Many Calories are in G Fuel Cans?

A single can of G Fuel contains no calories.

See, the zero-calorie label shouldn’t be meant to be taken literally. The FDA allows brands to put “zero-calorie” on the label if the product has a total of 5 calories. 

There can’t be negative calories either as your body needs at least five or more calories to function, which involves digesting food, sitting down, walking, running, and so on. Plus, the only thing you can eat or drink without gaining any calories is water.

How does G Fuel give energy if they only have five calories per can? 

G Fuel is loaded with ingredients like caffeine, sodium potassium, and vitamins that give you the energy you need during the day. So, rest assured that you’re getting enough nutrients for each serving.

Does G Fuel Can Have Sugar?

artificial sweeteners
It’s not sugar, but is it better?

Like other brands, G Fuel has zero sugar content and uses artificial sweeteners namely, sucralose and ace-k.

Both Sucralose (or Splenda) and Acesulfame potassium (Ace-K) are artificial sweeteners that are a sugar substitute mixed into food and drinks to give them flavor. In theory, that makes products “healthier” without taking away their sweet flavor.

Artificial sweeteners are very common in the food industry. If you look closely at the food labels, you’ll see Splenda on there a lot. Not surprising since Splenda is used to sweeten food and drinks from coffee, juice, and many more. It’s made through a chemical reaction that carefully replaces three hydrogen-oxygen molecule groups with chlorine molecules. 

Meanwhile, Ace-K isn’t as common outside of energy drinks, but it’s not far behind. It’s made through a chemical reaction that transforms acetoacetic acid and the mixture it forms with potassium. The result is a white crystalline powder that can sweeten food, but has a bitter aftertaste. 

Another reason why some might prefer artificial sweeteners is that they’re sweeter. Splenda is 600 times sweeter than regular table sugar while Ace-K is 200 times sweeter. But ultimately, Splenda is advised for those who need to watch their sugar, diet, and patients with diagnosed diseases.

Although both Ace-K and Splenda are controversial for a variety of reasons, both compounds are considered safe by the FDA. 

None of the studies that aim to tie them to side effects have been able to prove anything so far. There are also more studies that successfully verify their status as being safe to use and consume. 

How Much Caffeine is in G Fuel?

One can of G Fuel has 300mg of caffeine.

To give it some context, the thing to consider is the recommended daily limit for caffeine. Mayoclinic suggests that the most caffeine an adult can consume daily is 400mg. 300mg caffeine in G Fuel is 75% of that. 

What happens if you go over that 400mg limit? If your caffeine tolerance is high enough, you should be fine. 

Everyone reacts to caffeine differently and the individual person’s tolerance is one of the biggest things that influence how much caffeine they can consume in a day. 

Here’s a video that goes into detail about how caffeine tolerance works and the factors that influence it. It also explains other important things to consider like the half-life of caffeine and how it typically affects people’s bodies. 

The video provides with tips on how to avoid building too much tolerance on caffeine. So if you’ve been wanting to find ways to wean yourself off your morning coffee, this video might be of help for you.

If you’re not someone who has a high level of caffeine tolerance, drinking more than 400mg in a day will be bad for you.

While caffeine brings energy for your morning workouts and day activities, it could have yield negative reactions especially for those who had taken too much coffee or energy drink: You can experience side effects such as:

  • Headache
  • Insomnia
  • Anxiety
  • Irritability
  • Difficulty controlling bladder movements
  • Fast heartbeat
  • Muscle tremors (“Twitching”)
  • Insomnia
  • High blood pressure

If you’re sensitive to caffeine, you sure are more vulnerable to its side effects than the average person. 

Being sensitive to caffeine means that you may experience the drawbacks of caffeine even though you don’t reach the 400mg limit. You’ll more likely to lose sleep or have higher blood pressure, even if you only drank one cup of coffee. 

Aside from this, children, adolescents (including teens), and pregnant women are likewise sensitive to the effects of coffee. So, it’s advisable to stay clear of any caffeinated beverages like coffee and energy drinks.

If this is the case, you can switch to G Fuel Hydration which is sugar and caffein-free. They are available in many flavors like Dragon Fruit, Strawberry Lemonade, Fazeberry, and Blue Rocket Pop.

G Fuel Can Ingredients

In addition to G Fuel’s nutritional facts, you can also find its ingredients on the label.

  • Carbonated Water
  • Natural Flavors 
  • Artificial Flavors
  • Sodium Gluconate
  • Malic Acid
  • Caffeine 
  • Potassium Beta-Hydroxybutyrate 
  • Maltodextrin
  • Vitamin C
  • Vitamin B3
  • Vitamin B6
  • Vitamin B12
  • L-Tyrosine
  • Sucralose
  • Potassium Citrate
  • Citric Acid
  • Acesulfame Potassium
  • Green Coffee Bean Extract
  • Green Tea Extract
  • Turmeric Extract
  • Tart Cherry
  • Blueberry
  • Broccoli
  • Kale 
  • L-Theanine
  • Steviol Glycosides

To give you a clearer background of how G Fuel cans work, let’s look into some of its components that contribute to G Fuel’s benefits.


Tyrosine is an amino acid the body naturally produces from a different amino acid: phenylalanine. It plays an important role in the body since it helps produce many hormones that are essential to daily functioning.

The hormones that are produced with the help of tyrosine are:

DopamineManages the pleasure and reward centers. It’s also important for your memory and motor skills. 
Adrenaline and NoradrenalineReleased during fight or flight reactions. That means they prepare your body to either fight the perceived threat or run away from it. 
Thyroid hormonesRegulate metabolism. Produced in the thyroid 
Melanin Pigment. Creates your skin color, eye color, and hair color. The darker any of those are, the more melanin you have in your body. 
Substances produced with Tyrosine

Tyrosine is also common and a popular ingredient in dietary supplements. You can also find it in pre-workout drinks. 

Since consuming tyrosine improves your body’s levels of dopamine, norepinephrine, and adrenaline, it’s believed to improve your memory and ability to act in stressful situations. 

Besides G Fuel cans, you can also find tyrosine in some of these sources:

  • Cheese
  • Turkey
  • Fish
  • Dairy products
  • Other high-protein foods


Theanine is an amino acid that improves mental function. It works by helping the body transmit nerve impulses to the brain. 

Because of this, it’s commonly used as a treatment for anxiety, mental impairment, and stress. However, there’s not enough evidence on theanine treating some of these conditions. All we know is that it helps in easing mental balance and improving stability.

Theanine is also found in black teas, green teas, and some mushrooms. 

How Long Does a G Fuel Can Last?

Caffeine (Coffee)
Caffeine works no matter which beverage you’re consuming it through.

G Fuel typically takes 10-15 minutes to kick in and lasts for 4-6 hours after consumption.

Generally, caffeine needs 10-15 minutes to affect the body, the same foes for G Fuel. After that, it reaches peak levels in the bloodstream 30-60 minutes after you first drink it. 

From there, the amount you have in your blood will slowly decrease until it reaches its half-life 3-6 hours after consumption. 

The half-life of caffeine refers to how long it takes for the levels of caffeine in your blood to be lowered to half. It’s affected by how sensitive or tolerant your body is to caffeine. 

If you drank a can of G Fuel and started with 300mg of caffeine in your bloodstream, you’ll have 150mg 3-6 hours after consuming it. After 6 to 10 hours, caffeine’s effects will die down and can bring a feeling of fatigue or drowsiness.

Doctors also suggest that you drink caffeinated beverages not later than 6 PM or a few hours before your bedtime to avoid unhealthy sleeping patterns. If you’re determined to fix your body clock, you’re supposed to drink coffee or G Fuel only in the morning or after lunchtime, this way, you can prevent losing sleep at night.

Final Thoughts

A G Fuel can contain zero sugar and calories but has a large amount of caffeine and amino acids like tyrosine and theanine to get you more alert and perform better. 

It also kicks in within a few minutes after consumption and lasts for 4-6 hours. In my opinion, that’s more than enough time to get the job done and make sure it’s done well. That’s why I think G Fuel cans are definitely a good addition to the lineup. 

Since it has twice the amount of caffeine you’d find in the powder formula, it could be a good choice for people who have high caffeine tolerance. The 150mg in the tub version is enough for a lot of people (like a cup of coffee), but might be a bit too weak for others. 

Still, I really think you should remain careful with your doses.

You can include G Fuel in your morning routine or pre-workout. Since G Fuel’s recommended maximum daily dosage is 3 servings, you can have more than 1 can to power through your workday. If you’re new to the product, you can start with 1 can a day and see how many you can handle from there.

If ever, I’d just drink it whenever I really needed it to avoid the side effects and stretching my caffeine tolerance too much. That, and I’d rather not lose any more sleep than I have to.

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About Adrian Carter

Adrian writes about energy drinks and their ingredients to shine a light on the facts behind the brand names.


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