Hair Growth Rates: Scalp vs. Pubic Hair
No, scalp hair does not grow at the same rate as pubic hair—scalp hair grows significantly faster and for much longer periods.
Growth Rate Differences
Scalp hair grows approximately 1 cm per month 1, 2, while pubic hair grows at a slower rate with different growth characteristics 3, 4. The fundamental difference lies not just in the speed of growth, but in the duration of the active growth phase (anagen).
Why the Difference Exists
Duration of Active Growth Phase (Anagen)
- Scalp hair has an exceptionally long anagen phase that can last several years, allowing hair to grow to considerable lengths before entering the resting phase 3, 5
- Pubic hair has a much shorter anagen phase, which is why it reaches a maximum length and stops growing relatively short 3
- The differing lengths of hair in various body regions result primarily from differences in anagen duration rather than differences in actual growth rates 3
Hormonal Regulation
- Pubic hair requires relatively low levels of androgens to grow and does not require 5-alpha-reduction of testosterone to dihydrotestosterone 3, 4
- Facial and body hair require high testosterone levels and conversion to 5-alpha-dihydrotestosterone, while pubic and axillary hair follicles need much lower hormone levels 3, 4
- This hormonal difference contributes to the distinct growth patterns and characteristics between hair types 4
Practical Implications
- Scalp hair can theoretically grow indefinitely long due to its extended anagen phase, with the ability to continuously recruit new dividing progenitors 5
- Pubic hair reaches a genetically predetermined maximum length due to its shorter growth cycle 3
- The density and rate of pubic hair growth steadily decrease with age in both males and non-pregnant females 6