Ginseng, particularly Panax ginseng and Panax quinquefolius (American ginseng), has a long history of traditional use as an adaptogen—a substance believed to help the body resist stressors. Recent scientific research has provided some evidence supporting ginseng’s effects on the sympathetic nervous system (SNS), which is responsible for the body’s "fight or flight" response. Animal and human studies have indicated that ginsenosides (the active compounds in ginseng) can modulate the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic neurotransmission. Some research suggests that ginseng may help regulate stress-induced elevations in cortisol and catecholamines, thus supporting SNS balance.

For example, studies in rodents have shown that ginseng extract can reduce stress-induced increases in plasma corticosterone and norepinephrine, both of which are key markers of SNS activity. Human trials remain limited and results are mixed, but some have reported improvements in fatigue, cognitive performance under stress, and overall stress adaptation with ginseng supplementation.

While these findings provide a scientific basis for ginseng’s use in supporting the SNS, the evidence is moderate rather than strong. Most studies are relatively small and often use different ginseng preparations, making comparisons difficult. Further large-scale, well-controlled clinical trials are needed to fully validate ginseng’s effects on the sympathetic nervous system.