Yes, Nuun tablets work. In fact, there was a study published in Nutrients in 2020 comparing hydration levels after drinking Nuun versus plain water. Researchers found that Nuun improved fluid balance to a greater degree than water alone.There's anecdotal evidence, as well. Many Nuun customers swear by the tablets, saying they provide sustained energy without any crashes. People are pleasantly surprised by the taste of all the flavors too, saying Nuun tablets are much more delicious than other energy or hydration drinks.