The effectiveness of horsetail in treating gray hair is limited and needs to be judged on a case-by-case basis. Amaranthus is a kind of traditional Chinese medicine, which is sour and cold in nature. It has the effect of clearing heat, detoxifying, cooling blood and reducing swelling, and is often used in the treatment of dysentery, enteritis, herpes and eczema, etc. It has no clear effect on treating gray hair. However, amaranth has the effect of clearing heat and cooling the blood, and can be used with herbs such as dangpi, red peony and heshouwu to treat gray hair caused by heat in the blood. Amaranth is rich in copper, and its long-term consumption is effective in preventing the increase of gray hair due to the decrease of melanin production caused by copper deficiency. However, amaranth is a cold herbal medicine and it is not practical to consume it in large quantities for a long period of time, so it has limited effectiveness in treating gray hair. Patients with more severe gray hair are advised to identify the cause and actively treat it. Gray hair is usually considered to be caused by physiological factors, which can gradually alleviate the symptoms after lifting the triggers, while for gray hair caused by pathological factors, it needs to be treated under the guidance of a doctor: i. Physiological factors: 1. Ageing: for older people, metabolism slows down and melanin particles will decrease, thus causing gray hair to gradually appear, which generally requires no special treatment; 2. Nutritional deficiencies: long-term lack of copper, cobalt, and Iron and other inorganic salts, will affect melanin production, resulting in gray hair, need to adjust the diet, reasonable diet, can use the lack of trace elements to improve the symptoms, such as eating some black sesame, black beans, mulberry and other foods; 3, mental tension: long-term extreme mental tension or suffer from mental trauma, etc., is a psychogenic gray hair, need to adjust the emotions, if necessary, consult a psychiatrist; 4, other factors 4, other factors: such as overuse of the brain may also produce gray hair, part of the gray hair is also caused by congenital genetics. Second, pathological factors: common in vitiligo, due to the destruction of melanocytes, resulting in reduced melanin production, which generates white hair, also seen in the skin white spots, try to use hormone therapy, daily life to avoid strong sun exposure. In addition, some diseases such as hyperthyroidism, tuberculosis, pernicious anemia, etc. may also cause gray hair, should first treat the primary disease.