Guayaki Yerba Mate (can) carries more total caffeine per serving (150mg per 15.5 oz can vs 63mg per 1 oz shot), but ounce for ounce espresso is actually the stronger drink at about 63mg per fluid ounce against 10. 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.
Guayaki Yerba Mate (can) vs espresso: the numbers
| Guayaki Yerba Mate (can) | espresso | |
|---|---|---|
| Caffeine per serving | 150mg per 15.5 oz can | 63mg per 1 oz shot |
| Caffeine per fl oz | 9.7mg | 63.0mg |
| Servings to reach 400mg (FDA context) | 2.7 | 6.3 |
Sources: Guayaki Yerba Mate (can)'s figure is verified in our Guayaki Yerba Mate (can) caffeine guide against Guayaki product page (source); espresso's figure is verified in our espresso guide against USDA FoodData Central (source).
The concentration gap is the striking part: espresso packs roughly 7 times the caffeine per ounce. Sipping speed matters at that density; a 1 oz shot finished in minutes hits differently than the same milligrams spread over a slow cup.
Which one should you pick?
Pick espresso when you want the lighter dose or a slower ramp, and Guayaki Yerba Mate (can) 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
- Guayaki Yerba Mate (can): the full caffeine guide
- espresso: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
- Compare any two of 120+ drinks
FAQ
Does Guayaki Yerba Mate (can) or espresso have more caffeine? Guayaki Yerba Mate (can): 150mg per 15.5 oz can versus 63mg per 1 oz shot for espresso.
Which is stronger per ounce? espresso, at about 63.0mg per fluid ounce versus 9.7mg for Guayaki Yerba Mate (can).
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