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How
might estrogen treat androgenetic alopecia
Estrogen is a natural hormone made by both men and women, but in
men the production level is very low. Actually, estrogen is a family
of hormones, the "estrogens". The estrogens are converted
into different types by various enzymes in our bodies and Estradiol
is is the most common estrogen compound. Different estrogens have
subtly different chemical structures and they may have slightly
different modes of activity within the body system, but in general
the estrogens have similar characteristics and perform similar functions.
There are a very wide range of estrogen products either pure estrogen
or estrogen combined with other hormones. Some of the more common
sources and commercial brand names are listed below.
Estradiol is a common estrogen that is a typical method of supplying
additional estrogen as part of a treatment. Estradiol is provided
in several brand name products such as Estraderm (Ciba), Climara
(Berlex Labs), Estrace cream and tablets (Bristol-Myers Squibb),
Estradiol tablets (Watson), and Estrafem (Novo Nordisk in Denmark).
Ethinyl estradiol is also available and is typically used as an
oral contraceptive to suppress ovulation and gonadotrophin production.
The Ethinyl estradiol is combined with a progesterone such as Norethindrone
in these formulations. Brand name products include Demulen (Searle),
Nodette (Wyeth-Ayerst), Ortho-Novum (Ortho Pharmaceutical), and
Tri-Levlen (Berlex) among many others. Several products are also
available that provide a combination of estrogens in several conjugated
or esterified forms. Brand names include; Premarin (Wyeth-Ayerst),
Estratab (Solvay), and Estratest (Solvay).
Further estradiol derivatives include Estradiol Valerate and Estradiol
Cypionate. Commercial products with Estradiol Valerate include;
Delestrogen (Bristol Myers Squibb), Progynova and Progynon-Depot
(Schering). Estradiol Cypionate products are available as; Depogen
(Hyrex), Dep-gynogen (Forest), and Estro-cyp (Keene).
Estrogen is an indirect androgen antagonist. More estrogen in the
body depresses the net availability of androgens like testosterone.
It does this by a complicated feedback mechanism. Basically, high
estrogen levels reduce testosterone production. It also has an affect
on production of a molecule called sex hormone binding globulin
(SBHG). SBHG binds to testosterone and effectively renders it inactive.
The bound testosterone cannot be converted to dihydrotestosterone
and so cannot promote androgenetic alopecia. In addition, it has
been shown that cells in hair follicles can express receptors for
estrogens so estrogen may possibly have a direct action on hair
growth activity.
Clearly men cannot take oral estrogen without running the risk
of serious side effects. Typical side effects would include the
development of a female body hair pattern, loss of libido, and possible
breast development. Sporadic attempts have been made to use topically
applied solutions of estrogen to treat androgenetic alopecia. In
one randomized double blind study 51 men selected for androgenetic
alopecia and having a telogen rate greater than 20% used a preparation
of 0.025% 17alpha estradiol or placebo over six months. 63% of the
treated patients had a reduction in their telogen rate compared
to 37% of placebo users. 89% of estrogen users maintained hair growth
with no further progression of androgenetic alopecia. However, no
patient had significant hair growth with the treatment. So, it would
seem topical estrogen solutions may help maintain hair growth but
treatment does not stimulate hair regrowth for men with androgenetic
alopecia.
For women the story is different. Women can of course take estrogen
supplements orally or by injection without significant side effects.
Use of estrogen to treat androgenetic alopecia is especially popular
when hair loss onset began around menopause. Estrogen hormone replacement
therapy (HRT) may help to control the effective higher testosterone
concentrations that occur at menopause.
How
might estrogen treat androgenetic alopeciareferences
- Orfanos
CE, Vogels L. Local therapy of androgenetic alopecia with 17
alpha-estradiol. A controlled, randomized double-blind study.
Dermatologica. 1980;161(2):124-32.
- Orfanos
CE, Wustner H. Penetration and side effects of local estrogen
application in alopecia androgenetica. Hautarzt. 1975 Jul;26(7):367-9.
- Kiesewetter
F, Schell H, Seidel C, von Hintzenstern J. Proliferation behavior
of the anagen hair bulb in androgenetic alopecia before and
after local administration of 17 alpha- propylmesterolone--DNA
flow cytophotometry studies. Z Hautkr. 1990 Dec;65(12):1115-9.
- Wustner H, Orfanos
CE. Alopecia androgenetica and its local treatment with estrogen-
and corticosteroid externa. Z Hautkr. 1974 Oct 15;49(20):879-88.
- Orfanos CE, Panteleos
D. Estrogen-containing topical preparations in dermatology.
Hautarzt. 1977 Sep;28(9):500-1.
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