Also Known As: Minoxidil, Rogaine, Vanarex, Mintop
Minoxidil is an antihypertensive vasodilator medication which also slows or stops hair loss and promotes hair regrowth. Now off-patent, it is available over-the-counter for the treatment of androgenic alopecia. Minoxidil must be used indefinitely for continued support of existing hair follicles and the maintenance of any experienced hair regrowth. It is marketed under many trade names, including Rogaine/Regaine, Vanarex, Mintop and Loniten (oral), and Avacor Physician's Formulation (Avacor also produce a number of hair loss treatments that do not include minoxidil).Minoxidil was first used exclusively as an oral drug (with the trade name 'Loniten') to treat high blood pressure. However, it was discovered to have an interesting side effect: Minoxidil may cause increased growth or darkening of fine body hairs, or in some cases, significant hair growth. When the medication is discontinued, the hair loss will return to normal rate within 30 to 60 days. Upjohn Corporation produced a topical solution that contained 2% minoxidil to be used to treat baldness and hair loss, under the brand name Rogaine in the United States and Canada, and Regaine in Europe and the Asia-Pacific. Treatments usually include a 5% concentration solution that is designed for men, whereas the 2% concentration solutions are designed for women. The patent on minoxidil expired February 11, 1996. While the drug is available in the United Kingdom, it cannot be prescribed on the NHS, so patients must either buy it over-the-counter or have a private prescription for it.
In 2007, a new foam-based formulation of 5% minoxidil, which is claimed to be as effective as the liquid-based formulation, was introduced by Upjohn and marketed under the brand name Rogaine/Regaine Foam.
In 2011, it was announced that a generic version of minoxidil foam would be available beginning in March 2012
The mechanism by which minoxidil promotes hair growth is not fully understood. Minoxidil contains the nitric oxide chemical moiety and may act as a nitric oxide agonist. Similarly, minoxidil is a potassium channel opener, causing hyperpolarization of cell membranes. Minoxidil is less effective when there is a large area of hair loss. In addition, its effectiveness has largely been demonstrated in younger men who have experienced hair loss for less than 5 years. Minoxidil use is indicated for central (vertex) hair loss only. Minoxidil is also a vasodilator. Hypothetically, by widening blood vessels and opening potassium channels, it allows more oxygen, blood, and nutrients to the follicle. This may cause follicles in the telogen phase to shed, which are then replaced by thicker hairs in a new anagen phase.