GPLC has been shown in two studies to result in an increase in blood levels of nitrate/nitrite (a surrogate marker of nitric oxide; not a direct measure of nitric oxide), when used at a daily dose of 4.5 grams.
In another study, GPLC or a placebo was provided to resistance trained men for four weeks each, with a two-week washout period between each four-week period, using a double blind design [REF].