Androgenetic alopecia progresses through a predictable pattern of temple recession, frontal thinning, and crown loss over a period of years to decades. The Norwood scale maps seven stages of this progression, and understanding your current position on the scale helps predict future loss and determine when to intervene.
This guide covers the typical progression timeline, factors that accelerate or slow the process, and the critical windows where treatment has the greatest impact.
The Norwood Progression Pathway
Male pattern baldness follows a consistent anatomical sequence in the vast majority of men. The temples recede first, followed by the frontal hairline, then the crown, and finally the bridge between the two until only a horseshoe of hair remains.
Stage-by-Stage Progression
| Norwood Stage | What Changes | Typical Age of Onset | Time at This Stage |
|---|---|---|---|
| Norwood 1 | No recession, juvenile hairline | Pre-hair loss | Variable |
| Norwood 2 | Mild temple recession | 18-25 | 2-10 years |
| Norwood 3 | Deep M-shaped recession | 25-35 | 3-10 years |
| Norwood 3V | Temple recession + crown thinning | 25-35 | 3-8 years |
| Norwood 4 | Frontal and crown zones expand | 30-40 | 3-10 years |
| Norwood 5 | Bridge between front and crown thins | 35-50 | 5-15 years |
| Norwood 6 | Front and crown merge into one bald area | 40-55 | 5-15 years |
| Norwood 7 | Maximum pattern baldness, horseshoe pattern | 45-65+ | Terminal stage |
These timelines represent averages. Individual variation is substantial. Some men reach Norwood 7 by age 35. Others remain at Norwood 3 their entire lives.
Progression Speed Factors
Fast Progressors
Men who reach Norwood 3 or higher before age 25 are classified as fast progressors. They tend to reach advanced Norwood stages (5-7) earlier in life and often need treatment planning that accounts for continued rapid loss.
Characteristics of fast progressors:
- Visible recession before age 22
- Family history of early, extensive baldness
- Diffuse thinning across the top (not just temples)
- Rapid change between annual photos
Slow Progressors
Men who show only mild recession (Norwood 2-3) by age 40 are slow progressors. Their hair loss may never advance beyond Norwood 4, and the rate of change is gradual enough that medication alone can maintain a full appearance for decades.
Factors That Influence Speed
| Factor | Effect on Progression | Evidence |
|---|---|---|
| Genetics | Primary determinant of speed and severity | High |
| Age of onset (earlier = faster) | Strong predictor of eventual Norwood stage | High |
| Anabolic steroid use | Dramatically accelerates progression | High |
| Smoking | May accelerate via reduced follicle blood supply | Moderate |
| Finasteride/dutasteride use | Slows or halts progression in 80-90% | High |
| Minoxidil use | Slows progression, promotes some regrowth | High |
| Stress | Does not affect AGA directly (triggers telogen effluvium separately) | High |
| Diet | Severe deficiency can worsen shedding but does not drive AGA | Moderate |
The Miniaturization Gradient
Hair loss does not appear as a sharp boundary between bald and non-bald areas. Instead, there is a gradient where hair transitions from fully terminal (thick, pigmented) to vellus (thin, unpigmented) across a zone that can be several centimeters wide.
Understanding the Transition Zone
| Hair State | Diameter | Visibility | Treatment Potential |
|---|---|---|---|
| Terminal hair | 60-100 microns | Fully visible | N/A (healthy) |
| Early miniaturized | 40-60 microns | Slightly reduced | High response to medication |
| Intermediate | 20-40 microns | Thin, low contrast | Moderate response |
| Vellus | Under 20 microns | Invisible at normal distance | Low response to medication |
| Absent | Follicle dormant | No hair | Surgery needed for restoration |
This gradient is clinically important because hair that is still in the early or intermediate miniaturization stages responds best to DHT blockers like finasteride. Once a follicle has been dormant for years, medication alone is unlikely to revive it. This is why early intervention matters.
Critical Decision Windows
Window 1: First Signs of Recession (Norwood 2)
This is the optimal time to start medication. At Norwood 2, temple recession is mild, and the vast majority of follicles are still producing terminal hair. Starting finasteride at this stage preserves the most hair and provides the best long-term cosmetic outcome.
Intervention options: Finasteride 1mg daily, optional minoxidil
Window 2: Established Pattern (Norwood 3-4)
At Norwood 3 to 4, the loss pattern is clear, and a meaningful number of follicles have miniaturized. This is the most common stage for men to begin treatment because the cosmetic impact becomes noticeable. Both medication and surgical options are available.
Intervention options: Finasteride, minoxidil, hair transplant (1,500-3,500 grafts)
Window 3: Advanced Loss (Norwood 5-7)
At Norwood 5 and above, many follicles in the frontal and crown areas are dormant. Medication alone cannot restore lost coverage. Surgery is the primary option for restoring hair in these areas, supplemented by medication to protect remaining native hair.
Intervention options: Hair transplant (3,000-7,500 grafts), finasteride/dutasteride, SMP, combination approach
Tracking Your Progression
How to Monitor Changes
Accurate tracking requires consistent photography under the same conditions. Take photos monthly under the following protocol:
| Parameter | Standard |
|---|---|
| Lighting | Overhead bathroom light (consistent source) |
| Hair state | Dry, unstyled |
| Angles | Front, top-down, left temple, right temple, crown |
| Distance | Arm's length |
| Frequency | Monthly |
Comparing photos taken 6 to 12 months apart reveals progression that is invisible day-to-day. This documentation is also valuable when consulting with a surgeon, as it provides objective evidence of your progression rate.
Rate of Change Interpretation
| Change Over 12 Months | Classification | Recommended Action |
|---|---|---|
| No visible change | Stable or very slow progression | Monitor, consider starting medication |
| Slight thinning, same Norwood stage | Slow progression | Start finasteride if not already on it |
| Noticeable thinning, approaching next Norwood | Moderate progression | Finasteride + minoxidil, consult surgeon |
| Clear stage advancement | Fast progression | Aggressive medication, consider early transplant planning |
What Medication Does to Progression
Finasteride and dutasteride do not reverse the clock, but they effectively freeze it. By reducing DHT levels, they remove the trigger for further miniaturization in most men.
| Medication | Effect on Progression |
|---|---|
| Finasteride 1mg | Halts progression in 83-90% of men |
| Dutasteride 0.5mg | Halts progression in 85-95% of men |
| Minoxidil 5% | Slows progression, promotes partial regrowth |
| No treatment | Progression continues at individual rate |
For a man who starts finasteride at Norwood 3 and responds well, his hair loss pattern may remain at Norwood 3 indefinitely while on the medication. Without treatment, the same man might progress to Norwood 5 within 5 to 10 years.
Get Your Progression Assessment
Upload a photo at myhairline.ai/analyze for a free AI analysis of your current stage and visible miniaturization patterns. The assessment identifies your Norwood classification and helps you understand where you are in the progression timeline, so you can make informed decisions about when and how to intervene.