Minoxidil is available in a variety of medication dosage forms and can be used by 13 year old girls when the indications are met. Minoxidil is a peripheral vasodilator drug that has the ability to lower blood pressure and can be used clinically to treat hypertension. In addition the drug can be used topically to stimulate hair growth and can therefore be used to treat hair loss. For 13 year old girls, whether an individual can use minoxidil depends mainly on the dosage form of the drug; if it is in tablet form, then it can be used as a second or third line medication, subject to the drug’s indication of high blood pressure; However, if the Minoxidil used is a topical preparation such as gel, application, spray, etc., the drug indications are generally male pattern baldness and pemphigus, and may be used with caution in girls as young as 13 years of age under the supervision of a physician. Adverse reactions: The use of Minoxidil may cause some adverse reactions, the topical form of Minoxidil may cause skin irritation, skin sensitization phenomenon, while the oral form of Minoxidil may cause reflex sympathetic excitation, water and sodium retention, hair growth and so on. Contraindication: Minoxidil is contraindicated in those who are allergic to Minoxidil. Precautions: When Minoxidil is used to treat hypertension, sudden discontinuation of the drug may cause a rebound in blood pressure, so discontinuation of the drug should be achieved by gradual withdrawal of the drug, and the drug should be taken orally to measure blood pressure and body weight at regular intervals. Topical dosage forms of minoxidil are limited to topical use on the scalp. Minoxidil is a prescription drug, so it must be prescribed by a healthcare professional and used in strict accordance with medical advice.