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Androgenetic Alopecia

Male & Female Pattern Hair Loss — The Most Common Type

50%+ of men
Prevalence
by age 50
DHT + Genetics
Main Cause
hormonal
Age 20-30
Onset
typical start
Yes
Treatable
multiple options

What is Androgenetic Alopecia?

Also known as male-pattern or female-pattern baldness, androgenetic alopecia is the most common type of hair loss. It's hereditary and typically follows a predictable pattern. In men, it often starts with a receding hairline and crown thinning. In women, it usually presents as overall thinning with the hairline remaining intact.

The condition is driven by the hormone dihydrotestosterone (DHT), which causes genetically susceptible hair follicles to gradually miniaturize — producing thinner, shorter, less pigmented hairs with each growth cycle until the follicle eventually stops producing visible hair.

The DHT Mechanism

1

Testosterone converts to DHT — the enzyme 5-alpha reductase converts testosterone to DHT in the scalp

2

DHT binds to follicles — genetically susceptible follicles have receptors that bind DHT

3

Follicle miniaturization — the growth phase shortens, producing thinner, shorter hairs each cycle

4

Follicle dormancy — eventually the follicle stops producing visible hair entirely

Patterns in Men vs Women

Men (Norwood Scale)

  • • Receding hairline at temples (M-shape)
  • • Crown thinning develops separately
  • • Two areas merge in advanced stages
  • • Classified by 7 Norwood stages
  • View the Norwood Scale stages →

Women (Ludwig Scale)

  • • Diffuse thinning across the top
  • • Frontal hairline usually preserved
  • • Widening part line is key sign
  • • Classified by 3 Ludwig stages
  • • More common after menopause

Proven Treatments

Frequently Asked Questions

What causes androgenetic alopecia?

Androgenetic alopecia is caused by a combination of genetics and hormones, specifically dihydrotestosterone (DHT). DHT is a byproduct of testosterone that shrinks hair follicles over time (miniaturization), leading to thinner, shorter hairs until the follicle stops producing visible hair entirely. The sensitivity of your follicles to DHT is largely determined by genetics inherited from both parents.

At what age does androgenetic alopecia start?

It can begin as early as the late teens, though it is more commonly noticed in the mid-20s to 30s. By age 50, approximately 50% of men show visible signs of pattern hair loss. In women, it typically becomes noticeable after menopause, though it can start earlier.

Can androgenetic alopecia be reversed?

Androgenetic alopecia cannot be fully reversed, but it can be significantly slowed and partially reversed with treatment. Finasteride blocks DHT production and can regrow hair in many men. Minoxidil stimulates hair growth. Hair transplants permanently relocate DHT-resistant hair to thinning areas. The earlier treatment begins, the better the outcomes.

Is androgenetic alopecia the same in men and women?

No. In men, it follows the Norwood scale pattern — receding hairline and crown thinning. In women, it follows the Ludwig scale — diffuse thinning across the top of the scalp while the frontal hairline is generally preserved. Women also have different treatment options, as finasteride is not typically prescribed for women of childbearing age.

How is androgenetic alopecia diagnosed?

Diagnosis is usually clinical — a dermatologist examines the pattern and density of hair loss. In some cases, a pull test, scalp biopsy, or blood tests (to rule out thyroid issues or iron deficiency) may be performed. Trichoscopy (dermoscopy of the scalp) can reveal miniaturized hairs, a hallmark of androgenetic alopecia.

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