The Norwood-Hamilton Scale is the clinical gold standard for classifying male pattern hair loss. Dermatologists and trichologists worldwide use it to stage progression, guide treatment, and track results over time.
What Is the Norwood Scale?
Developed by Dr. James Hamilton in the 1950s and refined by Dr. O'Tar Norwood in the 1970s, the scale maps hair loss across seven primary stages based on the position of the hairline, the extent of temporal recession, and the spread of vertex (crown) thinning.
Understanding your stage is the first step toward effective treatment. The treatments that work best at Stage II don't look the same as those for Stage V. Stage matters.
The Seven Stages
STAGE I
No significant hair loss
The hairline sits in its natural juvenile position. No recession at the temples, no crown thinning. No intervention required — though this is the ideal time to establish a preventive protocol.
STAGE II
Slight temporal recession
A small recession begins at the temples. The hairline is slightly elevated. Hair loss is minimal and many men don't notice at this stage. First-line treatments (finasteride, minoxidil) are highly effective here.
STAGE IIa
Front recession
Recession extends slightly across the entire front hairline, not just the temples. Hair is still present and coverage is good. Highly treatable.
STAGE III
Deep temporal recession
The classic 'M-shaped' hairline. Temples are deeply recessed. Still coverable with styling. Finasteride has shown strong efficacy at this stage. Don't delay.
STAGE III VERTEX
Crown thinning begins
Recession at the temples plus the beginning of crown (vertex) thinning. Two fronts of loss are now active. Treatment remains effective but urgency increases.
STAGE IV
Significant loss — two zones
Extensive recession at the front and significant crown thinning. A strip of hair still separates the two areas. Hair loss has advanced significantly. Medication can slow or stop progression; regrowth is less reliable.
STAGE V
Bridge narrowing
The strip of hair between the front and crown is narrowing. Loss is extensive. Treatments can stabilize but full restoration is unlikely without surgical intervention (hair transplant).
STAGE VI
Bridge gone
The front and crown loss zones have merged. Only a horseshoe of hair remains at the sides and back. Medical treatment focuses on maintaining remaining hair. Transplant is the primary restoration option.
STAGE VII
Most advanced
Minimal hair remains on top. Only a narrow band of hair at the sides and back. The most advanced Norwood classification. Hair transplant can redistribute existing donor hair.
What Causes Male Pattern Hair Loss?
Male pattern hair loss (androgenetic alopecia) is primarily driven by dihydrotestosterone (DHT) — a byproduct of testosterone. In genetically susceptible men, DHT binds to hair follicles and causes them to miniaturize progressively, producing finer and shorter hairs until the follicle becomes dormant.
Genetics account for roughly 80% of your risk. Both maternal and paternal lines contribute. The myth that it "comes from your mother's side" is only partially true.
What Actually Works
Two treatments have strong clinical evidence and FDA approval for male hair loss:
Finasteride (Propecia): A daily oral medication that blocks 5-alpha reductase, the enzyme that converts testosterone to DHT. Reduces scalp DHT by approximately 70%. Clinical trials show it stops loss in ~85% of men and promotes regrowth in ~65% of men after 2 years. Requires a prescription.
Minoxidil (Rogaine): A topical vasodilator applied directly to the scalp. Available OTC. Extends the growth phase of hair follicles and increases blood flow. Most effective when combined with finasteride. Requires ongoing use — discontinuation leads to loss reversal within 3–6 months.
Starting earlier — at Stage II or III — produces significantly better outcomes. Both medications are better at preservation than restoration.
KNOW YOUR STAGE
Find out exactly where you are on the Norwood Scale. Free AI scalp analysis — takes 60 seconds.