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Hair
follicle growth rates by age and body region
Below is a brief table of hair growth rates defined for people
of different age and by the region of the body where the growth
rate analysis was made (after Myers 1951). Typically, females will
have slightly faster growing scalp hair than males of the same age
but slower growing hair elsewhere such as on the leg.
| Age category |
Daily growth rate for scalp hair (mm) |
Daily growth rate for eyebrow hair (mm) |
Daily growth rate for thigh hair (mm) |
| Pre puberty |
0.41 |
0.14 |
0.13 |
| Adolescent/young adult |
0.30 |
0.14 |
0.16 |
| Mature adult |
0.34 |
0.16 |
0.25 |
| Retirement age |
0.32 |
0.16 |
0.19 |
Thus the long hairs of the scalp have the fastest rate of hair
growth whereas the short hairs as in the eyebrow have the slowest
growth rate.
Hair
follicle regeneration after plucking by body region
Below is a brief table showing the number of days it took for
a hair follicle from which a hair was plucked to regenerate a new
hair fiber.
| Age category |
Regeneration rate for scalp hair (days) |
Regeneration rate for eyebrow hair (days) |
Regeneration rate for thigh hair (days) |
| Pre puberty |
134 |
58 |
77 |
| Adolescent/young adult |
138 |
65 |
88 |
| Mature adult |
112 |
56 |
141 |
| Retirement age |
139 |
73 |
240 |
The average number of days required for regeneration of hairs in
90% of the follicles from which hairs were plucked was 129 in the
crown of the scalp, 123 in the under arm, 121 in the thigh, 92 in
the chin, and 64 in the eyebrow. Hairs of the scalp regenerate more
quickly for males than females, but hairs of the under arm, and
thigh regenerate more quickly in females than males. Regions in
which hairs are long and grow at the fastest rate require the longest
interval for regeneration.
Hair
follicle growth rates references
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Ebling FJ. The hair cycle on the human thigh and upper arm. Br
J Dermatol. 1985 Jul;113(1):9-16.
- Randall
VA, Ebling FJ. Seasonal changes in human hair growth. Br J Dermatol.
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- Nagl W.
Different growth rates of pigmented and white hair in the beard:
differentiation vs. proliferation? Br J Dermatol. 1995 Jan;132(1):94-7.
- Van Neste D, De Brouwer B, Dumortier M.
Reduced linear hair growth rates of vellus and of terminal hairs
produced by human balding scalp grafted onto nude mice. Ann N
Y Acad Sci. 1991 Dec 26;642:480-2.
- Astore IP, Pecoraro V, Pecoraro EG. The
normal trichogram of pubic hair. Br J Dermatol. 1979 Oct;101(4):441-5.
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W. Assessment of rate of hair growth using a simple trichometer.
Med Biol Eng Comput. 1979 May;17(3):333-6.
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FP. Measurements of hair in normal newborns. Pediatrics. 1976
Jun;57(6):960-2.
- Pecoraro V, Astore I, Barman JM. Growth
rate and hair density of the human axilla. A. Comparative study
of normal males and females and pregnant and post-partum females.
J Invest Dermatol. 1971 May;56(5):362-5.
- Saitoh M, Uzuka M, Sakamoto M. Human hair
cycle. J Invest Dermatol. 1970 Jan;54(1):65-81.
- Priestley GC. Rates and duration of hair
growth in the albino rat. J Anat. 1966 Jan;100(1):147-57.
- Braun-Falco O. [Dynamics of normal and
pathological hair growth]. Arch Klin Exp Dermatol. 1966;227(1):419-52.
- Barman JM, Astore I, Pecoraro V. The normal
trichogram of the adult. J Invest Dermatol. 1965;44:233-43.
- Barth JH. Measurement of hair growth. Clin
Exp Dermatol. 1986 Mar;11(2):127-38.
- Munro DD. Hair growth measurement using
intradermal sulfur 35 cystine. Arch Dermatol. 1966 Jan;93(1):119-22.
- Myers RJ, Hamilton JB. Regeneration and
rate of growth of hairs in man. Ann N Y Acad Sci. 1951 Mar 27;53:562-8.
- Trotter M. The life cycles of hair in selected
regions of the body. Am J Phys Anthrop. 1924;7:427-37.
- Trotter M. Hair growth and shaving. Anat
Rec. 1928;37:373-79.
- Giovannini S. De la régénération des poils
aprés l'epilation. Arch f Mikrosec Anat. 1890;36:528-64.
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