G Fuel's 300mg can and Reign Total Body Fuel are the same drink by the numbers: 300mg of caffeine in a 16 oz can, which is 18.8mg per fluid ounce for both. There is no caffeine gap to argue about. Note that G Fuel also sells a 140mg can, and if that is the one in your fridge, Reign carries more than twice the caffeine.
G Fuel Energy (can) vs Reign Total Body Fuel: the numbers
| G Fuel Energy (can) | Reign Total Body Fuel | |
|---|---|---|
| Caffeine per serving | 300mg per 16 oz can | 300mg per 16 oz can |
| Caffeine per fl oz | 18.8mg | 18.8mg |
| Servings to reach 400mg (FDA context) | 1.3 | 1.3 |
Sources: G Fuel Energy (can)'s figure is verified in our G Fuel Energy (can) caffeine guide against G Fuel product page (source); Reign Total Body Fuel's figure is verified in our Reign Total Body Fuel guide against Caffeine Informer (source).
Which one should you pick?
Pick Reign Total Body Fuel when you want the lighter dose or a slower ramp, and G Fuel Energy (can) when you actually need the bigger hit and know your tolerance. If you are stacking either with other caffeinated drinks through the day, run the math against the 400mg reference rather than guessing.
For context, the FDA cites 400mg of caffeine a day as an amount generally not associated with negative effects in healthy adults. Tolerance and health vary, so treat these numbers as information, not advice.
Every drink in this comparison against Reign Total Body Fuel
Barista Life runs a separate page for each of these matchups. This table puts all of them in one place so you can see where Reign Total Body Fuel sits against the whole set, rather than one drink at a time.
| Drink | Caffeine per serving | Per fl oz | Servings to reach 400mg |
|---|---|---|---|
| Reign Total Body Fuel (the anchor here) | 300mg per 16 oz can | 18.8mg | 1.3 |
| G Fuel Energy (can, 300mg formula) | 300mg per 16 oz can | 18.8mg | 1.3 |
| 3D Energy | 200mg per 16 oz can | 12.5mg | 2.0 |
| V8 +Energy | 80mg per 8 oz can | 10.0mg | 5.0 |
| XS Energy | 80mg per 8.4 oz can | 9.5mg | 5.0 |
Checked against Caffeine Informer, Reign Total Body Fuel, G Fuel cans collection, G Fuel Energy (can, 300mg formula), Caffeine Informer, 3D Energy, Caffeine Informer, V8 +Energy, Caffeine Informer, XS Energy on 2026-08-17.
Per serving or per ounce: which number answers your question
Per serving tells you what one container puts in you, and it is the number that matters if you are counting your day against a reference like the FDA's 400mg. Per fluid ounce tells you how concentrated the drink is, which is what decides how fast it arrives.
The two numbers disagree constantly, because serving sizes in this category run from under 2 oz to 16 oz. A drink can carry less caffeine in total and still be the stronger thing in the glass. Both columns are in the table above so you do not have to pick one.
One thing to check before you use these numbers
G Fuel cans ship in two caffeine levels, 140mg and 300mg, and the flavor name does not tell you which one you have. The table uses the 300mg formula. If your can says 140mg, halve every number in the row.
Reaching the 400mg reference
The last column divides 400 by the caffeine in one serving, so it is the number of servings of that one drink to reach the FDA reference amount with nothing else in the day. Coffee, tea, soda and chocolate all count against the same total.
For context, the FDA cites 400mg of caffeine a day as an amount not generally associated with negative effects in healthy adults. Tolerance and health vary, so treat these numbers as information, not advice.
Sources
Every number on this page was checked against the source listed here on 2026-08-17.
- Caffeine Informer, Reign Total Body Fuel
- G Fuel cans collection, G Fuel Energy (can, 300mg formula)
- Caffeine Informer, 3D Energy
- Caffeine Informer, V8 +Energy
- Caffeine Informer, XS Energy
The rest of this comparison set
These pages cover the same ground from a different angle. They are still live, so here they are:
- 3D Energy vs Reign Total Body Fuel: which has more caffeine?
- V8 +Energy vs Reign Total Body Fuel: which has more caffeine?
- XS Energy vs Reign Total Body Fuel: which has more caffeine?
Related reading
- G Fuel Energy (can): the full caffeine guide
- Reign Total Body Fuel: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
- Compare any two of 120+ drinks
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Gear from this guide
FAQ
Does G Fuel Energy (can) or Reign Total Body Fuel have more caffeine? G Fuel Energy (can): 300mg per 16 oz can versus 300mg per 16 oz can for Reign Total Body Fuel.
Which is stronger per ounce? G Fuel Energy (can), at about 18.8mg per fluid ounce versus 18.8mg for Reign Total Body Fuel.
Comparing caffeine? The caffeine comparison tool puts hundreds of drinks side by side, and the caffeine curfew calculator can check your cutoff time for tonight.
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