Px occurs naturally in the body when the liver metabolizes, or breaks down, caffeine. Like caffeine, Px is a stimulant that increases alertness, reduces fatigue, and decreases drowsiness.
However, Px is less likely than caffeine to cause negative side effects, including “jitters”, anxiety, irritability, and nervousness. Additionally, Px has a shorter half-life and is cleared from the body faster than caffeine, so it is less likely to negatively affect sleep quality. Px may preserve dopaminergic neurons, helping to protect against age-related cognitive decline.
As compared to caffeine, paraxanthine has a higher oral LD50 (127-367 mg/kg for caffeine and 829-1601 mg/kg for paraxanthine; rodent). Likewise, paraxanthine has a higher no observed adverse effect level (NOAEL) as compared to caffeine (150 mg/kg body weight per day for caffeine and 185-300 mg/kg for paraxanthine). In animal and clinical studies, caffeine has been shown to be anxiogenic (i.e., anxiety increasing); in contrast, paraxanthine exhibits anxiolytic (i.e., anxiety decreasing) properties.
Because of its shorter history of use, the maximum allowable daily intake of paraxanthine is lower than caffeine (300 mg per day for paraxanthine as compared to the FDA recommended maximum of 400 mg per day for caffeine).
Both paraxanthine and caffeine are central nervous system stimulants. As such, paraxanthine is not intended for use by children and you should consult your physician if you are pregnant, lactating, have a medical condition, or are taking any medications.