Monster Rehab (Tea + Lemonade) has more caffeine than Monster Ultra (Zero Ultra) on both counts: 160mg per 15.5 oz can against 150mg per 16 oz can, and about 10mg per fluid ounce against 9. The serving sizes differ, so the table below shows both ways of counting.
Monster Ultra (Zero Ultra) vs Monster Rehab (Tea + Lemonade): the numbers
| Monster Ultra (Zero Ultra) | Monster Rehab (Tea + Lemonade) | |
|---|---|---|
| Caffeine per serving | 150mg per 16 oz can | 160mg per 15.5 oz can |
| Caffeine per fl oz | 9.4mg | 10.3mg |
| Servings to reach 400mg (FDA context) | 2.7 | 2.5 |
Sources: Monster Ultra (Zero Ultra)'s figure is verified in our Monster Ultra (Zero Ultra) caffeine guide against Caffeine Informer (source); Monster Rehab (Tea + Lemonade)'s figure is verified in our Monster Rehab (Tea + Lemonade) guide against Caffeine Informer (source).
Which one should you pick?
Pick Monster Ultra (Zero Ultra) when you want the lighter dose or a slower ramp, and Monster Rehab (Tea + Lemonade) 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
- Monster Ultra (Zero Ultra): the full caffeine guide
- Monster Rehab (Tea + Lemonade): 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 Monster Ultra (Zero Ultra) or Monster Rehab (Tea + Lemonade) have more caffeine? Monster Rehab (Tea + Lemonade): 160mg per 15.5 oz can versus 150mg per 16 oz can for Monster Ultra (Zero Ultra).
Which is stronger per ounce? Monster Rehab (Tea + Lemonade), at about 10.3mg per fluid ounce versus 9.4mg for Monster Ultra (Zero Ultra).
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