Sweet flag (Acorus calamus) has a long history of use in traditional medicine systems, such as Ayurveda and Traditional Chinese Medicine (TCM), for supporting mental and emotional balance. In Ayurveda, sweet flag (known as "Vacha") is described as a "medhya rasayana," meaning it is believed to rejuvenate and strengthen the mind. It is traditionally used to calm nervousness, improve clarity, and help with emotional disturbances, including excessive sensitivity, anxiety, and restlessness. Similarly, TCM practitioners have employed sweet flag to "open the orifices" and calm the mind, aiming to address symptoms such as confusion, emotional instability, and agitation.

However, scientific validation for these effects is limited. While some pharmacological studies suggest that sweet flag extracts have sedative and anxiolytic properties in animal models, robust clinical trials in humans are lacking. Most contemporary evidence for its use in supporting emotional sensitivity is thus rooted in its traditional application rather than modern scientific validation. Furthermore, there are safety concerns with certain compounds in sweet flag, such as β-asarone, which may be carcinogenic or neurotoxic at high doses.

In summary, sweet flag's use for emotional sensitivity is primarily justified by its traditional use as a calming and mind-supporting herb, with only modest preliminary scientific evidence and some safety concerns.