Abstract-An early observational study suggested that ginseng could elevate blood pressure. This caused concern because 4.5% of American adults use ginseng, with a popular choice being North American ginseng. To date, North American ginseng lacks hemodynamic evaluation; therefore, we conducted a randomized, double-blinded, controlled trial to investigate its effect on blood pressure in 16 hypertensive individuals (meanϮSD age 61.1Ϯ8.1 years; systolic/diastolic blood pressure 132.4Ϯ12.8/83.3Ϯ8.1 mm Hg; 13 on antihypertensives). We used 6 batches of North American ginseng root that varied in quality and ginsenoside content, representing the spectrum of this ginseng on the market. On 8 mornings, each participant was fitted with an ambulatory blood pressure monitor, which measured blood pressure during a 30-minute baseline period. Each participant then consumed in a randomized and double-blind fashion 3 g of encapsulated treatment: placebo (on 2 mornings) or powdered North American ginseng (on 6 mornings). After treatment, blood pressure was measured every 10 minutes for 160 minutes, and its change at each post-treatment time point relative to baseline was determined per individual and averaged, and the mean was obtained for the overall 160-minute period. None of the North American ginsengs or their mean differed from placebo in their effect on overall (160 minutes) mean blood pressure change. None affected blood pressure versus placebo at the 10-minute intervals; but their mean versus placebo increased systolic and diastolic blood pressure at 140 and 160 minutes, respectively, and lowered diastolic blood pressure at 100 minutes. 2,3 This is based on an observational study by Siegel published Ͼ25 years ago, which found that hypertension developed in 14 adults reporting the use of ginseng root. 4 In response, medical commentaries recommend that hypertensive individuals avoid ginseng. 3 More recently, animal studies 5,6 and randomized controlled clinical trials (RCTs) 7,8 show that Panax ginseng, the most consumed species of ginseng in the United States, exerts a neutral or lowering effect on BP. Although these outcomes contrast Siegel's finding, it should be noted that they pertain to a single ginseng species. Another commonly consumed species of ginseng in the United States is P quinquefolius, or North American ginseng (NAG), which ranks second to P ginseng for use. Together, these species comprise most of the ginseng that Ϸ9 million American adults consume annually. 9 However, to date, the effect of NAG on BP is unknown and could be important to address because this herb is used widely and acts biologically different from other ginseng species. 10 The importance of determining the effect of NAG on BP also holds from a phytochemical perspective. All ginsengs contain a group of triterpene glycosides called ginsenosides, which show antihypertensive efficacy in animals. Because the content of NAG and profile of ginsenosides differs from P ginseng, its potential effect on BP cannot be inferred from the latter and requir...