What causes a receding hairline
A receding hairline is usually the first sign of androgenetic alopecia, or male pattern hair loss. The driver is dihydrotestosterone (DHT), a hormone converted from testosterone by the enzyme 5-alpha-reductase. DHT binds to receptors on genetically sensitive follicles at the front and top of the scalp and shrinks them over successive growth cycles, a process called miniaturisation.
Miniaturisation happens in stages. With each cycle, the follicle spends less time in its active growth phase, so the hair it produces grows shorter, finer and lighter. Terminal hairs become vellus hairs, and eventually the follicle stops producing a visible hair at all. This is why a receding hairline thins and lightens before it clears, rather than disappearing overnight.
The pattern this produces was first described by James Hamilton in 1951 and refined by O’Tar Norwood in 1975, whose Hamilton-Norwood scale is still the standard today. A hairline typically recedes at the temples first, taking on an M shape from Stage 2 to Stage 3. Because the loss is hormonal and progressive, our surgeons plan against the male pattern baldness stages, so the design accounts for the thinning likely to appear behind the new hairline, not only the recession visible today.
Not every high hairline is pathological. A mature hairline settles back by roughly one to one and a half centimetres in the late teens and twenties, which is normal and is not the same as a receding hairline. Telling a mature hairline apart from early male pattern loss is one of the first things our surgeons assess, because it decides whether surgery is needed at all.