Dunkin Refresher (medium) carries more total caffeine per serving (99mg per 24 oz medium vs 68mg per 12 oz can), but ounce for ounce Mountain Dew Zero Sugar is actually the stronger drink at about 6mg per fluid ounce against 4. Which one "has more caffeine" depends on whether you measure the container or the concentration.
These are different categories of drink, which changes how the caffeine arrives. Energy drinks and sodas list an exact number because caffeine is a measured additive; brewed drinks vary with the beans and the brew, so their figures are compiled averages. The numbers here are the standard published values for each.
Mountain Dew Zero Sugar vs Dunkin Refresher (medium): the numbers
| Mountain Dew Zero Sugar | Dunkin Refresher (medium) | |
|---|---|---|
| Caffeine per serving | 68mg per 12 oz can | 99mg per 24 oz medium |
| Caffeine per fl oz | 5.7mg | 4.1mg |
| Servings to reach 400mg (FDA context) | 5.9 | 4.0 |
Sources: Mountain Dew Zero Sugar's figure is verified in our Mountain Dew Zero Sugar caffeine guide against PepsiCo product facts (source); Dunkin Refresher (medium)'s figure is verified in our Dunkin Refresher (medium) guide against Tasting Table / Dunkin figures (source).
Which one should you pick?
Pick Mountain Dew Zero Sugar when you want the lighter dose or a slower ramp, and Dunkin Refresher (medium) 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
- Mountain Dew Zero Sugar: the full caffeine guide
- Dunkin Refresher (medium): the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
FAQ
Does Mountain Dew Zero Sugar or Dunkin Refresher (medium) have more caffeine? Dunkin Refresher (medium): 99mg per 24 oz medium versus 68mg per 12 oz can for Mountain Dew Zero Sugar.
Which is stronger per ounce? Mountain Dew Zero Sugar, at about 5.7mg per fluid ounce versus 4.1mg for Dunkin Refresher (medium).
Comparing caffeine? The caffeine comparison tool puts hundreds of drinks side by side, and the caffeine curfew calculator can check your cutoff time for tonight.