Available under such trade names as Rogaine, Regaine, Avacor and Mintop, minoxidil is available over the counter primarily for treatment of androgenic alopecia, male pattern baldness. All brands contain minoxidil as their effective ingredient.
Minoxidil works best for younger adults who have a short history of hereditary hair loss on the tops of their heads. As baldness becomes more pronounced and continues, minoxidil is less effective or ineffective.
You may need to use regular strength (2%) minoxidil for at least 4 months, perhaps up to one year, before seeing effects. “Shedding” of some hair in the telogen phase prior to new hair growth is considered normal.
Hair growth ceases and new hairs disappear when treatment is discontinued.
Minoxidil is available in liquid and foam preparations, at concentrations of 2% and 5%. Women are usually directed to the 2% solution. Use of the higher concentration may cause more hair growth but may cause more or greater adverse effects as well.
How minoxidil actually works is still being studied. Although it allows more blood flow to hair follicles, this may not be the primary mechanism. A study by L’Oreal suggests that minoxidil activates an enzyme, PGHS 1, which helps promote hair growth.