Background: Hair loss is one of the most common side effects of chemotherapy, and can cause persistent negative emotions, further affecting therapeutic effects and reducing the quality of life. However, there are no clinically safe and effective methods to solve the problem at present. Our previous clinical and animal studies showed that a medicinal and edible decoction, YH0618, could significantly promote hair growth in cancer patients after chemotherapy, without interfering with the anti-tumor effects of chemotherapy. Besides, the theory of Chinese Medicine believes that the "Essence of the kidney is reflected on the hair". Therefore, this study will further explore the efficacy of YH0618 granule on chemotherapy-induced hair loss in patients with breast cancer by a randomized, double-blind, multi-center clinical trial and elucidate the potential mechanism from the aspect of kidney deficiency or renal dysfunction. Methods/design: Eligible breast cancer patients who will start chemotherapy will be randomly divided into group A (YH0618 granule) and group B (placebo). The chemotherapeutic agents contain taxanes or/and anthracyclines, and the chemotherapy regimen will be for at least six cycles with a cycle every 3 weeks. Subjects assigned to group A will receive YH0618 granules twice a day (6 g each time), 6 days a week, mixed with 300 ml warm water from the first to the fourth chemotherapy cycle. Subjects in group B will receive the placebo granule in the same manner. The primary outcome is the time point of occurrence of hair loss reaching grade II as assessed by the WHO Toxicity Grading Scale, and objective indices of hair quality and hair-follicle growth recorded by a hair and scalp detector before the fifth chemotherapy cycle. Secondary outcomes include changes of facial color and thumbnail color, grading of thumbnails ridging, assessment of quality life, level of fatigue, routine blood test results, hepatic and renal function, and certain medical indicators which can reflect kidney deficiency in Chinese Medicine. Discussion: This research is of great significance for the treatment of cancer and improving the quality of life of cancer patients. The study may provide the most direct evidence for meeting clinical needs and lay a solid scientific foundation for later product development.