Minoxidil is an antihypertensive vasodilator medication, also claimed to slow or stop hair loss and promote hair regrowth. It is available over the counter for the treatment of androgenic alopecia, also known as male pattern baldness, however any improvements, if experienced, disappear in the months following discontinuation of treatment. Minoxidil was first used exclusively as an oral drug to treat high blood pressure, however it was later discovered to have an interesting side-effect. Minoxidil may cause increased growth or darkening of fine body hairs. When the medication is discontinued, the hair will return to normal 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. In 2007 a new foam-based formulation of 5% minoxidil was claimed to be as effective as the liquid-based treatment for male pattern baldness. 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.