Pilot Study: Pharmacokinetics and Safety of Ginger

This study was intended to determine the pharmacokinetics of ginger metabolites in plasma and urine and effects of ginger powder on platelet and neuropsychological function. Subjects had no ginger or medications for 1 week prior to testing. The total sample was 40 healthy subjects, with no history of cognitive or neuropsychological problems; mean age was 29.9 years.

In Phase I, 10 male volunteers received 1 and 2 grams of ginger powder, with known 6-gingerol and 6-shogaol concentrations, in separate crossover studies. Plasma samples (every 20 minutes for 2 hours) and 1- and 2-hour post-dose urine samples were collected, and 6-gingerol, 6-shogaol, and 6-gingerdiol concentrations and platelet function determined. In Phase II, placebo or 2 grams of ginger were randomized to 16 males and 14 females. Subjects were tested three times, 1 week apart. After baseline testing, subjects were randomized to placebo or ginger for the second session and vice versa for the third. Neuropsychological function was assessed by the Web-based Headminder concussion resolution index 30 minutes post-dose.

In Phase I, metabolites were not found in 1-hour urine samples, but were in 2-hour postdose samples. In Phase II, ginger metabolites were found in 1-hour urine samples. Increased or decreased platelet function (from baseline) was found throughout 2 hours of testing. No differences were found between the placebo and ginger groups in neuropsychological function.

No metabolites were found in plasma samples, but were present in all 2-hour post-dose urine samples of individuals receiving 1 gram ginger powder and in 7 of 10 from individuals receiving 2 grams, suggesting that ginger constituents are absorbed within 2 hours and efficacy tests can be performed within this period. Ginger effects on platelet function were inconclusive.

Based on these non-significant results, we recommend ginger as a safe herbal alternative therapy for motion sickness.

Final report is available on NTRL: https://ntrl.ntis.gov/NTRL/dashboard/searchResults/titleDetail/PB2007107621.xhtml