Minoxidil USP is to treat hair loss. It is over-the-counter, comes in a range of strengths, and is commonly used topically or as a foam. The oral drug minoxidil was primarily created to treat high blood pressure, but because it also stimulates hair growth, it is also used to treat androgenic alopecia, or male- or female-pattern baldness. Minoxidil USP expands blood vessels on the scalp and boosts blood flow to the hair follicles. This may lengthen the hair cycle's growth phase, resulting in thicker and longer hair strands. It is believed that minoxidil directly affects hair follicles, encouraging their growth and halting further hair loss.