Caffeine & Sleep
Energy drink

Caffeine in Monster Ultra (Zero Sugar)

150mg
per 16 oz
≈ 2 coffees≈ 2 Red Bulls38% of FDA daily max

Is that a lot?

Monster Ultra (Zero Sugar) is 38% of the FDA’s recommended daily maximum, in a single 16 oz.

Green tea
28 mg
Espresso
63 mg
Red Bull
80 mg
Coffee
95 mg
Monster Ultra (Zero Sugar)
150 mg
FDA daily max · 400mg
Before bed

When can I drink Monster Ultra (Zero Sugar) and still sleep?

Your Monster Ultra (Zero Sugar) cutoff
You drink it at
Bedtime
Monster Ultra (Zero Sugar) · 150 mg · assuming an average ~5 h half-life
At bedtime
49 mg
should be fine
Latest safe Monster Ultra (Zero Sugar): 3:05 PM

How much caffeine is in Monster Ultra (Zero Sugar)?

Monster Ultra trims the sugar to zero while keeping the energy high, around 150 mg of caffeine in a 16 oz can. It's the lighter-tasting, sugar-free path to roughly two coffees' worth of caffeine.

ServingCaffeineSugar
16 oz150 mg0 g

Will Monster Ultra (Zero Sugar) affect your sleep?

At 150 mg, Ultra needs close to eight hours to fall under 50 mg, so a midday can can still be present at bedtime. The missing sugar doesn't change how long the caffeine sticks around.

Heads up
At 150 mg, a second Monster Ultra (Zero Sugar) in a day pushes you toward the FDA’s 400 mg ceiling — and that’s before any coffee or tea. Log everything in the calculator to see your real daily total.

Source: Manufacturer label

Related drinks

Monster Ultra (Zero Sugar) & sleep — FAQ

It can, sugar-free or not, 150 mg of caffeine takes hours to clear, so an afternoon Monster Ultra may still sit above the 50 mg threshold when you're trying to sleep.

Monster Ultra (Zero Sugar) has 150 mg per 16 oz — about 38% of the FDA’s 400 mg daily maximum for healthy adults. That’s roughly 2 cups of coffee.

It depends on your bedtime and how fast you clear caffeine. Use the calculator above to see when Monster Ultra (Zero Sugar) drops below the ~50 mg “ok to sleep” threshold for your bedtime.

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