Lion's mane (Hericium erinaceus) is a medicinal mushroom traditionally used in East Asian medicine, but its support of the sympathetic nervous system is primarily examined through modern scientific research. Preclinical studies have demonstrated that lion's mane contains bioactive compounds, such as hericenones and erinacines, which can promote nerve growth factor (NGF) synthesis and exert neuroprotective effects. Most research has focused on the mushroom’s potential for cognitive enhancement, neurogenesis, and support of the central and peripheral nervous systems, rather than specifically targeting the sympathetic nervous system. Some animal studies suggest that lion's mane may improve autonomic nervous system balance and modulate stress responses, indirectly influencing sympathetic activity.

However, direct evidence demonstrating a significant or targeted effect on the sympathetic nervous system in humans is limited. Clinical trials have explored lion's mane for mild cognitive impairment, anxiety, and depression, but these do not isolate sympathetic nervous system function as a primary endpoint. Thus, while mechanistic studies provide a rationale for possible support, especially through neurotrophic and anti-inflammatory pathways, the overall evidence specific to the sympathetic nervous system remains preliminary. More robust, targeted clinical studies are needed to confirm its efficacy in this context.