Mapping the progress. Where do you stand in the biological timeline of hair loss?
The Hamilton-Norwood scale is the gold standard for classifying Male Pattern Baldness (MPB). It helps the lab track how far along the thinning has progressed across 7 distinct stages.
Minimal to no recession. Stage 2 shows a slight "mature" hairline at the temples. Most men land here in their late 20s. Vigilance starts now.
The clinical definition of baldness begins. Deep recession at the temples, creating an M, U, or V shape. Vertex thinning may also appear.
Recession is more severe. There's a distinct "bridge" of hair separating the receding front from a bald spot on the crown (vertex).
The bridge of hair between the front and the crown begins to disappear. By Stage 6, the two balding areas have fully merged into one.
The final stage. Only a narrow "horseshoe" of hair remains around the sides and back of the head. This hair is usually DHT-resistant.