TOPICAL MINOXIDIL THERAPY
Minoxidil is an antihypertensive medication that causes vasodilation. In oral forms, it is used to treat high blood pressure, and a side effect that was noted early on was increased hair growth in patients on the medication.
Topical minoxidil (brand name Rogaine in the US) was then developed to provide this effect without systemic side effects. The reason this works to help hair loss is not fully understood. One theory is that by dilating the blood vessels in the scalp, it causes more telogen hairs to shed and be replaced by more robust anagen hair follicles.
Typically patients have to use this medication for approximately 6 months before deciding whether it is going to work or not. In the first few weeks of use, patients will notice INCREASED shedding which can be disconcerting. This is a known process that occurs as the resting hair follicles are shed. After a few weeks, these resting hairs are replaced by growing hairs, and the shedding stops.
Hair growth with topical minoxidil only continues as long as the medication is continued. Once the minoxidil is stopped, hair loss will typically resume after a few months.
In the United States, no prescription is needed for topical minoxidil. It is available in both a foam and a solution. Most physicians recommend that all patients, both men and women, use the 5% formulations, as the 5% has been shown to be superior to the 2%. There is not any difference in efficacy between the foam and the solution.