Currently there are two medicines that help - finasteride (Propecia®) and minoxidil (Regaine®). Neither is available on the NHS, so you need to pay the full price for them. Finasteride was launched in the UK in 2002, although it has been available in the USA since 1997. It works by blocking the conversion of testosterone to dihydrotestosterone. The hair follicles are then not affected by this hormone and can enlarge back to normal. In around 1 in 3 to 6 men taking finasteride, enough hair regrowth occurs for them to consider treatment helpful. Some points about finasteride include the following: It takes about four months for any effect to be noticed and up to 1-2 years for full hair growth. The balding process returns if treatment is stopped. Therefore, if successful, you need to carry on treatment to maintain the effect. Side-effects are uncommon. The most common is that about 2 in 100 treated men report loss of sex drive (libido). It does not work in women with male pattern baldness. You need a private prescription to get it from a pharmacy. Minoxidil lotion is a rub-on treatment that you can buy at pharmacies without a prescription. It is not clear how it works. The higher-strength solution (5%) is for men only and is more effective than the 2% solution. The 5% strength is now also available as a foam. There is debate as to how effective it is. It is most effective when used early on rather than when a lot of hair has already been lost. It seems that it is best used to prevent further hair loss but some hair regrowth occurs in some users. Some points about minoxidil include the following: It needs to be rubbed on the scalp every day. It usually takes four months or more for any effect to be noticed. Treatment needs to be continued indefinitely. Any new hair that does regrow falls out two months after treatment is stopped. It is quite expensive. It may work in some women who have male pattern baldness. Side-effects are uncommon - for example, skin irritation or a rash sometimes occurs.