Rockstar Pure Zero vs C4 Performance Energy: which has more caffeine?

Rockstar Pure Zero has more caffeine than C4 Performance Energy: 240mg vs 200mg in the same 16 oz can. That is a 40mg gap, and since the cans match, the per-serving number is the whole story.

Rockstar Pure Zero vs C4 Performance Energy: the numbers

Sources: Rockstar Pure Zero's figure is verified in our Rockstar Pure Zero caffeine guide against Caffeine Informer (source); C4 Performance Energy's figure is verified in our C4 Performance Energy guide against Caffeine Informer (source).

Which one should you pick?

Pick C4 Performance Energy when you want the lighter dose or a slower ramp, and Rockstar Pure Zero 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.

Related reading

• Rockstar Pure Zero: the full caffeine guide
• C4 Performance Energy: the full caffeine guide
• The verified caffeine database
• Every drink compared: the comparisons index
• Compare any two of 120+ drinks

FAQ

Does Rockstar Pure Zero or C4 Performance Energy have more caffeine? Rockstar Pure Zero: 240mg per 16 oz can versus 200mg per 16 oz can for C4 Performance Energy.

Which is stronger per ounce? Rockstar Pure Zero, at about 15.0mg per fluid ounce versus 12.5mg for C4 Performance Energy.