In Traditional Chinese Medicine (TCM), Zi Shi Ying belongs to the 'Herbs that anchor and calm the Spirit' category. These herbs are substances that tranquilize the Mind and treat symptoms such as restlessness, palpitations, anxiety or insomnia. They tend to have sedative properties by weighing the Qi downwards and should generally be used for a limited time only.
Furthermore Zi Shi Ying is Warm in nature. This means that Zi Shi Ying tends to help people who have too much 'Cold' in their body, although with less effect than a plant that would be Hot in nature. Balance between Yin and Yang is a key health concept in TCM. Those who have too much Cold in their body are said to either have a Yin Excess (because Yin is Cold in nature) or a Yang Deficiency (Yang is Hot in Nature). Depending on your condition Zi Shi Ying can help restore a harmonious balance between Yin and Yang.
Zi Shi Ying also tastes Sweet. The so-called 'Five Phases' theory in Chinese Medicine states that the taste of TCM ingredients is a key determinant of their action in the body. Sweet ingredients like Zi Shi Ying tends to slow down acute reactions and detoxify the body. They also have a tonic effect because they replenish Qi and Blood.
The tastes of ingredients in TCM also determine what Organs and Meridians they target. As such Zi Shi Ying is thought to target the Heart, the Kidney and the Lung. In addition to regulating Blood flow, in TCM the Heart is believed to be the store of the 'Mind' which basically refers to someone's vitality. The Kidneys do not only regulate the urinary system but also play a key role in the reproductive system and the growth and aging process of the body. In addition to performing respiration, the Lungs are thought in TCM to be a key part of the production chain for Qi and the Body Fluids that nourish the body.