Norwood Scale: AGA Hair Loss Stages I–VII

The Norwood-Hamilton scale (commonly called the Norwood scale) is the standard classification system for male androgenetic alopecia (AGA). Developed by James Hamilton in the 1950s and revised by O’Tar Norwood in 1975, it describes seven stages of progressive hair loss from the hairline and vertex.

The Seven Stages

Stage	Description	Finasteride Candidacy
I	No significant recession; mature hairline	Prophylactic use possible; discuss with dermatologist
II	Slight recession at temples; minimal thinning	Strong candidate; early intervention most effective
III	Deeper temporal recession; early vertex thinning (IIIa/IIIv)	Strong candidate; high follicle preservation potential
IV	More significant frontal/temporal loss; expanding vertex	Good candidate; realistic goal is stabilization + modest improvement
V	Large bald areas front and vertex; narrowing bridge	Viable; set expectations on stabilization vs. reversal
VI	Front and vertex areas merged; sides retained	Limited regrowth likely; primarily prevents further loss
VII	Only temporal ring remains; very advanced loss	Limited benefit; primarily prevents remaining hair from further thinning

Self-Assessment vs. Clinical Assessment

Men can use the Norwood scale for rough self-assessment using photographs, but a dermatologist or trichologist can provide more accurate staging using trichoscopy (dermoscopy of the scalp) to assess follicle miniaturization density, which can detect AGA before macroscopic hair loss is obvious.

See: DHT and hair loss mechanism | Shedding vs. hair loss | Finasteride for AGA | Results timeline