Does Yerba Mate Dehydrate You? Caffeine, Electrolytes and Hydration
Updated:
One of the most common questions about yerba mate is whether it dehydrates you. It contains caffeine, caffeine is a mild diuretic, and diuretics cause fluid loss — so the concern is logical. The answer, however, is more nuanced than a simple yes or no, and it matters if you are drinking yerba mate regularly or using it as a substitute for coffee.
Does caffeine actually dehydrate you?
Caffeine is a mild diuretic, meaning it can increase urine output. However, the research on caffeine and net hydration status tells a more complicated story. Studies consistently show that at typical consumption levels — up to around 400mg of caffeine per day — caffeinated drinks do not cause net dehydration in habitual consumers. The water content of a cup of coffee, tea or yerba mate far exceeds any fluid lost through the mild diuretic effect.
The picture is different for people not habituated to caffeine, or for very high consumption levels, where the diuretic effect becomes more pronounced. But for regular, moderate drinkers, caffeinated drinks including yerba mate are generally considered to contribute positively to daily fluid intake.
Yerba mate compared to coffee
Yerba mate contains roughly 85mg of caffeine per 8oz cup — slightly less than a standard cup of coffee (around 95mg). So its potential diuretic effect is comparable to but slightly lower than coffee at equivalent serving sizes.
There is one practical difference worth noting. Yerba mate also contains theobromine, a compound also found in cacao and tea. Theobromine has a mild vasodilatory effect but does not share caffeine’s diuretic properties — which means a cup of yerba mate may produce slightly less diuretic response per mg of stimulant compounds than pure caffeine alone.
Does yerba mate contain electrolytes?
Yes, to a modest degree. Yerba mate leaves contain magnesium, potassium, calcium and manganese. How much of these minerals ends up in a brewed cup depends on steeping time, temperature and how much leaf is used, but it is a legitimate part of the picture. These minerals are electrolytes — they play a role in fluid balance and cellular function. The amounts in a standard cup are modest relative to daily requirements, but they are present.
The practical answer
For most people drinking one to three cups of yerba mate per day as part of normal fluid intake, it is unlikely to cause dehydration. The water in each cup more than compensates for any mild diuretic effect. If you are using yerba mate as a substitute for coffee and drinking similar quantities, your hydration status is unlikely to change significantly.
As with any caffeinated drink, drinking very large amounts, or relying on it as your primary source of fluids without water alongside it, is not ideal. And if you are exercising heavily or in hot weather, plain water remains the most efficient form of hydration.
Our yerba mate
Our organic yerba mate tea bags and loose leaf are air-dried, unsmoked and Soil Association certified organic, sitting within our organic herbal tea range. For more on what yerba mate is, where it comes from and how to brew it, our yerba mate guide covers the practical detail.
2 comments
Interesting piece. It would be helpful if, rather than generic comments on mineral content, mg or %NRV could be listed by herbal tea type. I am also wondering what it tastes like, as I’ve never come across this S American brew.
I have found this very interesting and might have a go at trying this out.