C4 Smart Energy vs Redline Xtreme: which has more caffeine?

Redline Xtreme has more caffeine than C4 Smart Energy on both counts: 316mg per 8 oz bottle against 200mg per 16 oz can, and about 40mg per fluid ounce against 12. The serving sizes differ, so the table below shows both ways of counting.

C4 Smart Energy vs Redline Xtreme: the numbers

Sources: C4 Smart Energy's figure is verified in our C4 Smart Energy caffeine guide against Cellucor / Caffeine Informer (source); Redline Xtreme's figure is verified in our Redline Xtreme guide against Caffeine Informer (source).

The concentration gap is the striking part: Redline Xtreme packs roughly 3 times the caffeine per ounce. Sipping speed matters at that density; a 8 oz bottle finished in minutes hits differently than the same milligrams spread over a slow cup.

Which one should you pick?

Pick C4 Smart Energy when you want the lighter dose or a slower ramp, and Redline Xtreme 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

• C4 Smart Energy: the full caffeine guide
• Redline Xtreme: the full caffeine guide
• The verified caffeine database
• Every drink compared: the comparisons index
• Compare any two of 120+ drinks

FAQ

Does C4 Smart Energy or Redline Xtreme have more caffeine? Redline Xtreme: 316mg per 8 oz bottle versus 200mg per 16 oz can for C4 Smart Energy.

Which is stronger per ounce? Redline Xtreme, at about 39.5mg per fluid ounce versus 12.5mg for C4 Smart Energy.