Male pattern baldness is characterized by hair receding from the lateral sides of the forehead (known as a “receding hairline”) and/or a thinning crown (balding to the area known as the ‘vertex’). Both become more pronounced until they eventually meet, leaving a horseshoe-shaped ring of hair around the back of the head. More than 95% of hair thinning in men is male pattern baldness, or and rogenetic alopecia.