Jatamansi (Nardostachys jatamansi) is a herb widely used in traditional Ayurvedic and Unani medicine, especially for its calming and restorative effects on the nervous system. Historically, it has been employed to alleviate stress, anxiety, insomnia, and other conditions associated with overactivity of the mind—symptoms that, in modern terms, relate to overactivation of the sympathetic ("fight or flight") nervous system and underactivation of the parasympathetic ("rest and digest") system. The root and rhizome are typically used in formulations aimed at promoting relaxation, sleep quality, and emotional balance.

Although there are a few preliminary laboratory and animal studies indicating that Jatamansi extracts may possess anxiolytic, antidepressant, and neuroprotective effects, robust clinical evidence in humans remains limited. Most of the support for its use in modulating the parasympathetic nervous system comes from centuries of traditional practice rather than well-controlled scientific studies. Thus, while there is a plausible rationale based on traditional usage and some promising preclinical results, the overall evidence remains modest and primarily traditional in nature.