Minoxidil tincture can be used clinically for the treatment of seborrheic alopecia and patchy baldness. Increasing the dosage and frequency of use will not only not increase the efficacy, but may also cause skin sensitization, irritation, itching, etc. At the same time, the percutaneous absorption of the medication in overdose may also lead to tachycardia, angina pectoris, and enhancement of the side-effects of other medications (e.g., erectile hypotension). The principle of Minoxidil tincture in treating hair loss may be to make the scalp blood vessels dilate, promote the flow of blood circulation so as to improve the micro-environment of hair growth, and promote the growth of hair. Some patients feel that their hair loss is severe at the beginning of the medication, which is due to the fact that the drug speeds up the metabolism of the hair follicles when it takes effect, causing the hairs in the resting phase to fall out prematurely. According to the drug description of minoxidil tincture, the main components of the drug are minoxidil and ethanol, which may lead to scalp allergy, local irritation and itching if used too much. And minoxidil is a peripheral vasodilator, when used in excess, the drug can be absorbed into the bloodstream through the skin, which may lead to tachycardia, angina pectoris, enhancement of guanethidine-induced upright hypotension and so on. For patients who use minoxidil tincture to treat hair loss, it is recommended to read the drug instructions carefully and follow the doctor’s instructions to standardize the drug treatment.