How much caffeine is in Rockstar Zero Carb?

A 16 fl oz can of Rockstar Zero Carb has 160 to 240 mg of caffeine.

That's about 2 cups of brewed coffee, and half of the 400 mg a day the FDA cites for most healthy adults.

Source: rockstarenergy.com · checked 10 Nov 2026

When did you have it?

Had at 3 pm, about 70 mg is still in you at an 11 pm bedtime. That might affect your sleep.

Ranges: the chart uses the middle of the published range (200 mg for this size).

Bedtime

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Latest time to drink it

For an 11 pm bedtime, most people should finish a 16 fl oz can of Rockstar Zero Carb by about 12:30 pm. The table works it out for other bedtimes and for how sensitive you are: it is the latest time to start one so that the caffeine left stays under the line all night.

Bedtime	Very sensitive under 25 mg	Average under 50 mg	Not very sensitive under 100 mg
9 pm	5:30 am	10:30 am	3:30 pm
10 pm	6:30 am	11:30 am	4:30 pm
11 pm	7:30 am	12:30 pm	5:30 pm
Midnight	8:30 am	1:30 pm	6:30 pm
1 am	9:30 am	2:30 pm	7:30 pm

For a 16 fl oz can of Rockstar Zero Carb, average clearance (half-life 5 h), 8 hours of sleep. "Any time" means even one at bedtime stays under the line.

How long it lasts

The caffeine from a 16 fl oz can of Rockstar Zero Carb peaks in your blood about 75 minutes after you start it, at roughly 171 mg. Half of it is gone in about 5 hours for an average adult; that ranges from roughly 3 to 7 hours, and longer in pregnancy or with some medicines.

Time after	3 hours	6 hours	9 hours	12 hours
Still in you	140 mg	93 mg	61 mg	40 mg

So one had at 3 pm leaves about 70 mg at 11 pm. How long caffeine lasts explains the curve.

How it compares

Rockstar Zero Carb is stronger than 53% of the 41 energy drinks we track, by caffeine per serving.

Per fluid ounce (13 mg) it is stronger than 49% of them.

To reach 400 mg in a day you would need about 2 of these.

Less caffeine

Java Monster Mean Bean 188 to 200 mg, 15 fl oz can
Bloom Sparkling Energy 180 mg, 12 fl oz can
Full Throttle 161 mg, 16 fl oz can

More caffeine

5-hour Energy Extra Strength 230 mg, 1 shot
Rockstar Punched 240 mg, 16 fl oz can
Celsius Essentials 270 mg, 16 fl oz can

Same caffeine: 3D Energy, 5-hour Energy, Alani Nu Energy Drink.

FAQ

Is Rockstar Zero Carb high in caffeine?

Yes, very. A 16 fl oz can of Rockstar Zero Carb has 160 to 240 mg, which is 2.1 times an 8 fl oz cup of brewed coffee (95 mg).

Can I drink Rockstar Zero Carb at night?

Not if you want to sleep well. Had at 7 pm, it leaves about 122 mg in an average adult at an 11 pm bedtime, above the 50 mg most people sleep fine with. The latest time for an 11 pm bedtime is about 12:30 pm.

How long does the caffeine in Rockstar Zero Carb last?

It peaks about 75 minutes after you start it. Of the 160 to 240 mg, about 93 mg is still in you 6 hours later and 40 mg after 12 hours, for an average adult with a 5-hour half-life.

Does Rockstar Zero Carb have more caffeine than a cup of coffee?

Yes. A 16 fl oz can of Rockstar Zero Carb has 160 to 240 mg; an 8 fl oz cup of coffee has 95 mg.

Method and limits

The caffeine figure comes from rockstarenergy.com; recipes, brewing and batches vary, so a real serving can differ. The curves use a standard one-compartment model with an average 5-hour half-life and a sleep-friendly line of 50 mg; your own body may clear caffeine faster or slower. How it works has the details.

These are estimates for information, not medical advice. If you are pregnant, ask your doctor; common guidance is under 200 mg a day.

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