Paraxanthine is a primary metabolite of caffeine, formed in the body after caffeine consumption. Recent research has focused on paraxanthine as a potential ergogenic (performance-enhancing) aid in athletic and exercise contexts. Scientific studies suggest that paraxanthine shares many of caffeine's physiological effects, such as central nervous system stimulation, increased alertness, and reduced perception of fatigue. Importantly, some human trials have shown that paraxanthine supplementation can improve reaction time, increase focus, and enhance endurance performance, paralleling or even exceeding the effects observed with caffeine. Unlike caffeine, paraxanthine appears to produce these benefits with fewer adverse effects such as jitteriness or anxiety, and it may have a more favorable cardiovascular profile.

Evidence for paraxanthine's efficacy as an athletic aid primarily comes from controlled laboratory studies and pilot human trials conducted since 2021. These studies have demonstrated improved cognitive and physical performance in exercise settings, such as resistance training and endurance cycling. However, large-scale, long-term studies are still limited, and most of the available data are from acute intake scenarios. Overall, while paraxanthine is a relatively new supplement in the sports nutrition market, the available scientific evidence supports its use for athletic and exercise performance enhancement, though further research is needed to confirm long-term safety and efficacy.