The kidneys store essence, and their vitality is reflected in the hair. Kidney deficiency can lead to dry, brittle, thinning, and graying hair. The core of nourishing hair by tonifying the kidneys lies in replenishing kidney yin and benefiting essence and blood. In daily life, one should consume more black foods such as black mulberries, black goji berries, sesame, and black beans, along with ingredients like Chinese yam and goji berries. Additionally, ensuring adequate sleep and reducing stress can strengthen and nourish hair from its root.