Black Ginger (Kaempferia parviflora) for Nutraceuticals: From Methoxyflavone Marker Standardisation to Pharmacokinetics and Human Evidence

Black ginger (Kaempferia parviflora) rhizome extracts are marketed across Asia for physical performance, metabolic health and male sexual function, and randomised trials now support several of these uses. Existing reviews summarise pharmacology or pool clinical outcomes but do not ask whether the extracts tested are comparable. This narrative review links quality control, pharmacokinetics and clinical evidence. Methoxyflavones, chiefly 5,7-dimethoxyflavone, 5,7,4’-trimethoxyflavone and 3,5,7,3’,4’-pentamethoxyflavone, are the accepted markers, but their content varies more than twofold between raw materials and far more between extract types. Using data reported in two trials, a 90-milligram dose of an ethanol extract supplied about 31 times more pentamethoxyflavone and 13 times more trimethoxyflavone than 90 milligrams of a water extract, yet both are described simply by extract mass. In humans, only pentamethoxyflavone and trimethoxyflavone were detected in blood, in a subset of volunteers, with half-lives of two to three hours, consistent with oral bioavailability of 1 to 4 per cent in rats. Lipid-based and cyclodextrin formulations increased exposure more than twentyfold in rats. Applying the quality-marker concept, the review proposes marker-based dosing, fingerprint specifications, sensitive bioanalysis and a reporting standard so that black ginger trials become comparable and reproducible.