"Two years ago, I watched a very convincing
video by Dr. John Lee about the advisability of using
progesterone cream to regulate the estrogen level
in a woman's body. He maintains that he has established
that progesterone cream use by his patients alleviated
many of their menopause-related problems, and reversed
or prevented bone loss, heart problems, and many other
health problems for which HRT is normally recommended.
I wonder if any research has been done by other physicians
to prove or disprove his claims. " "I am
58 and I have been avoiding HRT due to a history of
breast cancer in my family. I have been menopausal
since a D & C a year and a half ago. I exercise
vigorously most of the year, and believe I am in good
physical condition. A recent bone density scan showed
a slight decrease in bone density in my hip, although
my spine was normal. I have been using progesterone
cream for 2+ years. It has appeared to alleviate my
(minor) menopause problems, but I wonder if there
is any other medical evidence that the progesterone
cream will keep me healthy into old age."
Sue
This question often comes up because of the search
for non-estrogen preventatives of many of the changes
that take place in a woman's physiology after menopause.
Dr Lee addresses the use of progesterone (natural
progesterone and not synthetic progestins) cream as
an alternative to estrogen both pre-menopausally and
post-menopausally. Since you are asking about its
use after menopause, let us confine our discussion
to the postmenopausal use of progesterone cream. The
scientific data which specifically address the use
of progesterone cream applied to the skin are not
very extensive but there is some work that has been
done.
The main premises in the postmenopause that Dr Lee
alleges, as best I can tell from reading his material,
is that progesterone will build bone (and thus help
prevent osteoporosis), relieve hot flashes, and help
prevent the new onset of coronary artery disease.
Is the progesterone cream absorbed from the skin?
The doses that Dr Lee recommends for menopause is
15 mg/day for 25 days of the calendar month. He suggests
being off for 5 or 6 days each month to allow the
progesterone receptors not become desensitized by
a constant dose of progesterone. He recommends the
creams that contain 450-500 mg of progesterone per
ounce, which is 1.6% by weight or 3% by volume. Using
1/4 teaspoon daily would provide about 20 mg/day.
One scientific study using 64 mg a day on the skin
showed a rise in salivary levels of progesterone but
not in blood levels (1). Salivary levels reflect an
accumulation in the body over time rather than an
instant blood level. Another study looked at twice
the recommended dose, 20 mg twice a day and they found
a slight change in the blood level of a metabolite
of progesterone but no change in FSH, estradiol or
testosterone levels (2). This is important because
if any positive effect of progesterone is because
of metabolism to an estrogen substance, thereby negating
the intent of using it in the first place, you would
expect both FSH and testosterone levels to lessen
somewhat which is what they do if estrogen is given.
Finally, a third study looking at absorption found
that when 30 mg a day was given for two weeks, followed
by 60 mg a day for two weeks, raised serum levels
of progestone and it could be detected in the range
of 1.6 to 3.3 ng/mL. In premenopausal women being
treated for luteal phase defects, 100 mg a day of
vaginal progesterone cream is needed to raise serum
levels significantly (3).Thus the 20 mg a day recommended
by Dr. Lee is a somewhat low dose compared to that
needed to show a rise in blood levels.
Does progesterone cream prevent hot flashes and osteoporosis?
One controlled scientific trial which compared the
20 mg a day dose of progesterone cream recommended
by Dr Lee to a placebo in 102 women after menopause
found that the progesterone cream did improve hot
flashes significantly (83% reduction vs 19% reduction)
but neither placebo or the cream produced an improvement
in bone density such as you would expect for estrogen
(4). This was the only study I could find that directly
examined the effect of progesterone cream on osteoporosis.
We have known for many years that estrogen actually
causes an increase in bone density. When synthetic
progestins are added to estrogen, they do not blunt
this positive bone growth effect at all. In fact when
HRT with both estrogen and progestin are given to
frail, 75 year old women, there is still a net gain
of bone density in the spine and hip within a year
(4.3% and 1.7%) versus placebo (0.4% and -0.1%) (5).
This is interesting because Dr Lee maintains that
estrogens do not help the elderly retain bone as well
as younger postmenopausal women. We know that medroxyprogestone
acetate (Provera®), a synthetic progestin, when
given alone does not prevent bone loss (6), although
there is some suggestion that when it is added to
estrogen, it enhances the positive bone accumulation
effect of the estrogen (7). In animals, medroxyprogesterone
acetate does not seem to prevent bone loss when used
by itself (8), but I could not find natural progesterone
studies on human bone loss at all other than the cited
negative study above.
It is very difficult to prove or disprove whether
progesterone cream could have some positive effect
on bone loss. It may have a little effect, but certainly
it is not as much preventative effect as etrogens.
I would say that if osteoporosis or osteopenia is
already present, then an established osteoporosis
treatment such as alendronate (Fosamax®) or estrogen
would be recommended.
Can progesterone cream prevent endometrial cancer
when taken with estrogen?
In the woman who has not had a hysterectomy, there
is concern about estrogen supplementation alone causing
uterine cancer. Progestins and progesterone supplementation
are recommended when postmenopausal estrogen is given
to prevent stimulating the development of ovarian
cancer. A legitimate question is whether using progesterone
cream can prevent the proliferative effect on the
lining of the uterus (endometrium). One study has
shown that both skin applied progesterone cream (1.5%
twice a day) as well as vaginally applied progesterone
cream can neutralize this proliferative effect of
estrogen on endometrium (9). The skin cream was also
much preferred over vaginal application.
While this does not prove that progesterone cream
can be used this way to add to estrogen and prevent
endometrial cancer, it is very likely that it has
this positive effect. Remember that we use transdermal
skin patches containing both estrogen and progestin
as hormone replacement therapy and assume that the
skin absorption of the progestin will help prevent
endometrial cancer if a uterus is still present. The
above study is good evidence that progesterone cream
probably has this same beneficial effect.
Will progesterone cream give me the heart benefit
that estrogens do?
There many studies over the last 30+ years that estrogens
used postmenopausally can decrease the new occurence
of heart disease. It is thought to do this partially
by causing a dilation effect on the heart blood vessels
and by raising high density lipoproteins (HDL), the
good cholesterol. Some synthetic progestins are known
to constrict heart vessels so there is concern whether
natural progesterone can do this also. Using a vaginal
progesterone cream, one study has shown that unfortunately
progesterone has a constricting effect on blood vessels
(10).
In general, synthetic progestins have a blunting
or blocking effect on the ability of estrogen to raise
good cholesterol (HDL) but it does not block the bad
cholesterol (LDL) lowering effect of estrogens; the
net result of combined estrogen and progestin HRT
is to lower total cholesterol (11). Micronized progesterone
by mouth has this same general blunting effect (12)
but in another study it did not blunt the estrogen
induced HDL increase as much as the synthetic progestins
did (13).
I would say that natural progesterone alone probably
has a negative effect on heart health but that if
you are taking estrogen, you get a more positive heart
health effect with HRT using natural progestrone than
you would taking most synthetic progestins. It is
hard to tell, however, whether this is a major or
a more minor heart health benefit.
In summary, the progesterone cream should be somewhat
beneficial for the hot flashes of menopause but there
is no evidence at that current time that would recommend
it for an osteoporosis prevention agent or for any
new heart disease prevention effect.While we have
not discussed the effect of progesterone on vaginal
dryness of menopause, a woman should keep in mind
that progesterone alone does improve vaginal dryness
at all if that is a menopause problem.
|
