Dermatology
What Is Male Pattern Baldness?
Last reviewed: May 2026 · Haute MD Editorial Team
Male pattern baldness (androgenetic alopecia) is the most common form of hair loss in men, affecting approximately 50% of men by age 50. It is caused by a genetic sensitivity of hair follicles to dihydrotestosterone (DHT), a hormone derived from testosterone. Over time, DHT causes hair follicles to miniaturize, producing progressively thinner and shorter hairs until the follicle ceases production entirely.
The Norwood Scale
Male pattern baldness is classified using the Norwood scale from I (minimal hairline recession) to VII (only a band of hair remains on the sides and back). Most men present in the II-IV range when they first seek treatment.
Treatments for male pattern baldness
FDA-approved treatments include minoxidil (topical and oral) and finasteride (oral). Minoxidil prolongs the growth phase of hair follicles. Finasteride blocks the conversion of testosterone to DHT and is effective in approximately 90% of men. PRP therapy delivers growth factors to the scalp. Low-level laser therapy (LLLT) is FDA-cleared for hair loss. Surgical options include FUE and FUT hair transplant.
When should treatment begin?
Treatment is most effective when started early — before significant follicle miniaturization has occurred. Treatments maintain existing hair rather than regrowing hair from permanently damaged follicles. Starting treatment at the first signs of thinning produces the best long-term outcomes.
Frequently Asked Questions
Is male pattern baldness inherited from the mother's side?
The genetics of male pattern baldness are complex and can be inherited from either parent. The maternal grandfather myth is an oversimplification — genes from both sides of the family contribute.
Can male pattern baldness be reversed?
Treatments can slow progression and in some cases partially reverse early miniaturization, but they cannot restore hair from follicles that have permanently ceased production. Hair transplants can redistribute existing hair.
Does finasteride have sexual side effects?
A small percentage of men on finasteride (approximately 2-3%) experience sexual side effects including decreased libido or erectile dysfunction. These effects are typically reversible upon discontinuation.
What is the success rate of hair transplant for male pattern baldness?
Hair transplants using FUE or FUT techniques have very high success rates — transplanted hairs are not sensitive to DHT and continue to grow permanently. The result depends on donor hair density and the skill of the surgeon.
Get Help Now
Speak with a Haute MD Dermatology physician
Dr. Daniel Scott Karempelis
Dermatologist
Dermatology · Atlanta, Georgia, GA
View Profile
Dr. Bertha Baum
Board-Certified Dermatologist
Dermatology · Aventura, FL
View Profile
Dr. Victoria Cirillo-Hyland
Dermatologist
Dermatology · Bryn Mawr, PA
View ProfileAre you a Dermatology physician?
Join Haute MD Network and have your profile featured alongside these answers.
Apply for the NetworkRelated Guides
Guide · DERMATOLOGY
What Causes Hair Loss?
Hair loss has many causes including genetics, hormones, nutritional deficiencies, and stress. Learn the most common causes and treatment options.
Read GuideGuide · DERMATOLOGY
What Causes Female Hair Loss?
Female hair loss is caused by hormonal changes, genetics, nutritional deficiencies, and stress. Learn the causes, patterns, and treatments.
Read GuideGuide · DERMATOLOGY
What Is PRP for Hair Loss?
PRP (platelet-rich plasma) for hair loss uses your own growth factors to stimulate follicle activity. Learn how it works, results, and what to expect.
Read Guide