as a response to this article:
"As progesterone does not exist in genetic girls until age 14, it is clear that progesterone cannot
possibly have any effect on breast development in the genetic female."
It showed that estrogen without progesterone is sufficient for breast growth for most genetic females. But some genetic females do developing breasts after 14. The presence of progesterone in the breasts could be the contributing factor in those cases.
"Puberty is a complex process and, in addition to oestrogen, there are many other hormones
which regulate it. These include prolactin, insulin and growth hormone. "
According to an article by Jenn (
http://www.estrogendominanceguide.com/about): "Estrogen can also direct cells to make receptors for other hormones, including progesterone, which is another hormone that instructs cells in the breast to multiply. "
This indirectly explained that HRT is more effective for MTF persons in their puberty, the higher amount of growth hormone present in this age group could be the contributing factor.
Dr. Richard J. Curtis:
"b) [progesterone] reduces the number of oestrogen receptors in the breast (oestrogen must bind to receptors in
order to work. Even if there are good oestrogen levels in the bloodstream, if there are no
receptors, it cannot work);"
The assertion that progesterone reduces the number of oestrogen receptors is incorrect according to data of C.W.Xiao and A. K. Goff
Centre de Recherche en Reproduction Animale, Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Rue Sicotte,
St-Hyacinthe, Quebec J2S 7C6, Canada:
"Progesterone (50 nmol l\m=-\1)had no
effect on the number of oestradiol or progesterone receptors (P > 0.05). However,
progesterone inhibited the stimulatory effect of oestradiol. In epithelial cells, the lower
concentrations of oestradiol (0.1 and 1 nmol l\m=-\1) stimulated the number of progesterone
receptors (P = 0.05) after 4 days culture, whereas the highest concentration of oestradiol
(10 nmol l\m=-\1), progesterone (50 nmol l\m=-\1) and progesterone (50 nmol l\m=-\1) plus oestradiol (1
nmol l\m=-\1) had no effect. After culture for 8 days, the stimulatory effect of oestradiol
decreased. In contrast to progesterone receptors, the number of oestradiol receptors
increased with oestradiol concentration (P < 0.01). These data show that the number of
progesterone receptors was higher in the stromal cells than in epithelial cells, whereas the
number of oestradiol receptors was higher in the epithelial cells than in stromal cells.
Oestradiol upregulates its own receptor and increases the number of progesterone
receptors in both cell types in vitro, whereas progesterone has little effect, but inhibits the
effects of oestradiol on progesterone receptors."
The article by Dr. Richard J. Curtis is biased in favour of other hormones to the exclusion of progesterone in the contribution of breast growth, if progesterone is also present in the system, estrogen can also direct cells to become progesterone receptors, these receptors will in turn cause cells to multiply.
"The actions of progesterone in the natal female are:
o cerebral: causing mood change;
o uterine: to prepare the uterus for implantation;
o pregnancy: to maintain pregnancy;
o breast: enabling duct formation for lactation. N.b. Ducts are very small and contribute little to
breast size."
The article failed to mention other beneficial actions of progesterone in the natal female which according to the article by Dr. Michael Lam, MD, MPH:
"*progesterone acts as an antagonist to estrogen.*
For example, estrogen stimulates breast cysts while progesterone
protects against breast cysts. Estrogen enhances salt and water
retention while progesterone is a natural diuretic. *Estrogen has been
associated with breast and endometrial cancers, while progesterone has a
cancer preventive effect.* Studies have shown that pre-menopausal women
deficient in progesterone had 5.4 times the risk of breast cancer
compared to healthy women."
Regarding progesterone causing mood change, according to the same the article by Dr. Michael Lam,
" Symptoms
include water retention, breast swelling, and fibrocysts in the
breast,
depression, headache, gallbladder problems, and heavy
periods. The excessive estrogen from ERT also lead to increased
chances of DNA damage, setting a stage for endometrial and breast
cancer. **"
Again...
"***Stress. Stress causes adrenal gland exhaustion as well as
reduced progesterone output.* This tilts the estrogen to
progesterone ratios in favor of estrogen. Excessive estrogen in
turn causes insomnia and
anxiety, which further taxes the adrenal
glands. This leads to a further reduction in progesterone output
and even more estrogen dominance. After a few years in this type
of vicious cycle, the adrenal glands become exhausted. This
dysfunction leads to blood sugar imbalance, hormonal imbalances,
and chronic fatigue.**"
It states estrogen dominance (higher estrogen to progesterone ratio) is cause of depression and anxiety, a mental condition (same as mood) cause by hormonal imbalance.
Regarding hormonal imbalance effecting the physical health condition:
"*According to the late Dr. John Lee, the world's authority on natural
hormone therapy, the key to hormonal balance is the modulation of
progesterone to estrogen ratio. For optimum health, the progesterone to
estrogen ratio should be between 200 and 300 to 1. * **"
Dr. Michael Lam:
"**What is so bad about estrogen dominance? It is the root cause of a
myriad of illnesses. Conditions associated with this include fibrocystic
breast disease, PMS, uterine fibroids, breast cancer, endometriosis,
infertility problems, endometrial polyps, PCOS, auto-immune disorders,
low blood sugar problems, and menstrual pain, among many others. * *"
Out of these illnesses breast cancer, auto-immune disorders, low blood sugar problems can equally happened to MTF transgenders due to estrogen dominance.
Dr. Richard:
"Progesterone is contraindicated in people who have, or who have had, any of the following:
liver dysfunction, breast cancer, heart disease, stroke, arterial disease.
In the natal woman, progesterone is given largely in three scenarios;
1. as a contraceptive;
2. to suppress menstrual blood loss;
3. to protect the uterus from developing cancer.
Trans women have none of these issues therefore, progesterone administration is not indicated."
Trans women do share liver dysfunction, breast cancer issues.
Dr. Richard:
"The reason for not giving progesterone unless absolutely necessary, is because of the risk. The
most serious of which are breast cancer and thrombosis."
In term of breast cancer risks, studies show estrogen contribute 75%, progesterone can reduce the breast cancer risks contributed by estrogen, although progesterone itself contribute 65% to breast cancer risks. In theory, if progesterone reduce the risk contributed by estrogen to 0%, what is left is 65% risk.
In term of venous thrombosis, usage of progesterone may indeed increase the risk.
Dr. Richard:
"Progesterone reduces the effectiveness of oestrogen as it:
a) increases the breakdown of oestrogen in the liver;"
Progesterone support optimum oestrogen metabolism, that result in reduction of bad oestrogen (16-OH metabolite) which can lead to development of breast cancer. In the optimum oestrogen metabolism, 2-OH metabolite (good oestrogen) is produced which generates harmless estrogenic activity in the body.
Infer to Douglas C. Hall, M.D. :
"The ultimate biologic effect of estrogen in the body depends on how it is
metabolized. The metabolism of estrogen takes place primarily in the liver
through Phase I (hydroxylation) and Phase II (methylation and glucuronidation)
pathways, which allow the estrogen to be detoxified and excreted from the body.
Hydroxylation —Hydroxylation yields three metabolites that vary greatly in
biological activity: 2-hydroxyestrone (2-OH),16-OH, or 4-OH.14 The 2-OH
metabolite is generally termed the "good" estrogen because it generates very
weak (and therefore potentially less harmful) estrogenic activity in the body.
In contrast, the 16-OH and 4-OH metabolites show persistent estrogenic activity
and may promote dangerous tissue growth.14-17 In fact, women who metabolize a
larger proportion of their estrogen via the 16-OH metabolite may be at
significantly greater risk of developing breast cancer.1,14-16,18,19 Therefore,
shifting estrogen balance toward a less estrogenic state through promotion of
the 2-OH pathway may prove very beneficial in improving a variety of conditions
related to elevated or imbalanced estrogen levels. "
Dr. Richard:
"c) [progesterone] is converted into testosterone which inhibits the actions of oestrogen."
Small amount of testosterone in trans-women is required to maintain healthy libido. If trans-women is pre-op and can produce small amount of testosterone, then progesterone is not needed for this purpose.
In general, progesterone is needed if:
1. additional breast growth is sought
2. maintain libido in post-op trans-women
3. partial prevention of breast cancer (still left 65% risk)
4. money is not an issue
Progesterone is not needed if:
1. additional breast growth is not sought
2. maintain libido in pre-op trans-women
3. prevent venous thrombosis is important
4. saving cost
