Androgenetic Alopecia Explained: The Hair Loss Lasers Can Treat

Androgenetic alopecia — pattern hair loss — is the most common cause of thinning in both men and women. It's the condition every FDA-cleared home laser device is cleared to treat, so it's worth understanding whether it's what you have.

What causes it

Two things combine: inherited sensitivity in certain follicles, and dihydrotestosterone (DHT), a hormone made from testosterone. In sensitive follicles, DHT gradually shortens the growth phase and shrinks the follicle, so each new hair is finer and shorter than the last. Over years the follicle may stop producing visible hair altogether.

How it looks

• Men: the hairline recedes at the temples and the crown thins, eventually meeting. Staged with the Norwood scale.
• Women: the part widens and the top of the scalp thins diffusely, usually without a receding hairline. Staged with the Ludwig scale.

See Norwood and Ludwig scales.

What it isn't

Sudden, patchy or painful hair loss is usually something else: alopecia areata, telogen effluvium (stress or illness shedding), thyroid disease, iron deficiency, or scarring alopecias. These need a doctor, and lasers aren't the treatment.

What helps

Treatments with the most evidence for pattern hair loss are:

• Minoxidil (topical), for men and women
• Finasteride (oral, men), which lowers DHT
• Low-level laser therapy, drug-free, FDA-cleared for men and women — see what is LLLT

Many dermatologists recommend combining approaches. ADD CITATION Laser therapy fits well because it works on a different pathway from the drugs and can be used alongside them — read using a laser cap with minoxidil.

Why timing matters

All of these treatments work on follicles that still exist. The earlier you start, the more there is to protect. If you think you have pattern thinning, our rankings compare the five best-known devices.