Topical application of amaranth may cause redness, swelling, breakage of the skin, and even allergy, so it is recommended to use it under the guidance of a doctor. Amaranth, herb, a kind of traditional Chinese medicine, sour taste, cold nature, attributed to the liver, large intestine meridian. It has the effect of cooling the blood to stop bleeding, clearing heat and removing toxins, and clearing lymph and swelling. Fresh amaranth can be pounded and properly applied externally to treat dengtu (acute infectious disease, visible redness of the skin like paint) swelling and pain, carbuncle sores, carbuncle sores and ulcers and other conditions. However, if the dosage and time of use are not grasped well, it is easy to cause skin redness and swelling or other skin lesions, and allergies are prone to skin allergic reactions. Amaranth is a traditional Chinese medicine that clears heat and relieves dampness, and can be used externally as well as in combination with other traditional Chinese medicines, decocted for internal use, and the dosage should be strictly in accordance with the doctor’s instructions. The adverse reactions or contraindications to internal use are not clear. Whether it is applied externally or taken internally, it needs to be carried out under the guidance of a traditional Chinese medicine practitioner, and the time and frequency of external application need to be strictly controlled, so as not to cause adverse reactions.