Experiments determined hair growth could be stimulated, if the minoxidil was applied topically. The experiments proved promising enough to convince the FDA to allow it's sale as a prescription drug. Minoxidil is the ONLY substance that has been laboratory tested to restore hair growth in people. However, it varies considerably from person to person in how well or poorly it works. Hair that has been lost through male pattern baldness seem particularly resistant.
Male pattern is the gradual loss of hair above the forehead.
In some men it eventually reaches the crown of the head. Minoxidil is almost completely ineffective for this type of hair loss. Instead, the manufacturer recommends it for the type of baldness that occurs at the very top and upper back of the head. This bald spot is the most likely to be helped by minoxidil. Your age may also play an important roll in restoring hair growth with minoxidil.