by John R. Lee, M.D.* and Virginia Hopkins
Authors of "What Your Doctor May Not Tell You About
Menopause" and "What Your Doctor May Not Tell You About
Pre-Menopause"
Q: What is
progesterone?
A:
Progesterone is a steroid hormone made by the corpus luteum of the ovary
at ovulation, and in smaller amounts by the adrenal glands. Progesterone
is manufactured in the body from the steroid hormone pregnenolone, and is
a precursor to most of the other steroid hormones, including cortisol,
androstenedione, the estrogens and testosterone.
In a normally cycling female, the corpus luteum produces 20 to 30 mg of
progesterone daily during the luteal phase of the menstrual cycle.
Q: Why do
women need progesterone?
A:
Progesterone is needed in hormone replacement therapy for menopausal women
for many reasons, but one of its most important roles is to balance or
oppose the effects of estrogen. Unopposed estrogen creates a strong risk
for breast cancer and reproductive cancers.
Estrogen levels drop only 40-60% at menopause, which is just enough to
stop the menstrual cycle. But progesterone levels may drop to near zero in
some women. Because progesterone is the precursor to so many other steroid
hormones, its use can greatly enhance overall hormone balance after
menopause. Progesterone also stimulates bone-building and thus helps
protect against osteoporosis.
Q: Why not
just use the progestin Provera as prescribed by most doctors?
A:
Progesterone is preferable to the synthetic progestins such as Provera,
because it is natural to the body and has no undesirable side effects when
used as directed.
If you have any doubts about how different progesterone is from the
progestins, remember that the placenta produces 300-400 mg of progesterone
daily during the last few months of pregnancy, so we know that such levels
are safe for the developing baby. But progestins, even at fractions of
this dose, can cause birth defects. The progestins also cause many other
side effects, including partial loss of vision, breast cancer in test
dogs, an increased risk of strokes, fluid retention, migraine headaches,
asthma, cardiac irregularities and depression.
Q: What is
estrogen dominance?
A: Dr. Lee
has coined the term "estrogen dominance," to describe what
happens when the normal ratio or balance of estrogen to progesterone is
changed by excess estrogen or inadequate progesterone. Estrogen is a
potent and potentially dangerous hormone when not balanced by adequate
progesterone.
Both women who have suffered from PMS and women who have suffered from
menopausal symptoms, will recognize the hallmark symptoms of estrogen
dominance: weight gain, bloating, mood swings, irritability, tender
breasts, headaches, fatigue, depression, hypoglycemia, uterine fibroids,
endometriosis, and fibrocystic breasts. Estrogen dominance is known to
cause and/or contribute to cancer of the breast, ovary, endometrium
(uterus), and prostate.
Q: Why would
a premenopausal woman need progesterone cream?
A: In the
ten to fifteen years before menopause, many women regularly have
anovulatory cycles in which they make enough estrogen to create
menstruation, but they don't make any progesterone, thus setting the stage
for estrogen dominance. Using progesterone cream during anovulatory months
can help prevent the symptoms of PMS.
We now know that PMS can occur despite normal progesterone levels when
stress is present. Stress increases cortisol production; cortisol
blockades (or competes for) progesterone receptors. Additional
progesterone is required to overcome this blockade, and stress management
is important.
Q: What is
progesterone made from?
A: The USP
progesterone used for hormone replacement comes from plant fats and oils,
usually a substance called diosgenin which is extracted from a very
specific type of wild yam that grows in Mexico, or from soybeans. In the
laboratory diosgenin is chemically synthesized into real human
progesterone. The other human steroid hormones, including estrogen,
testosterone, progesterone and the cortisones are also nearly always
synthesized from diosgenin.
Some companies are trying to sell diosgenin, which they label
"wild yam extract" as a medicine or supplement, claiming that
the body will then convert it into hormones as needed. While we know this
can be done in the laboratory, there is no evidence that this conversion
takes place in the human body.
Q: Where
should I put the progesterone cream?
A: Because
progesterone is very fat-soluble, it is easily absorbed through the skin.
From subcutaneous fat, progesterone is absorbed into capillary blood. Thus
absorption is best at all the skin sites where people blush: face, neck,
chest, breasts, inner arms and palms of the hands.
Q: What is
the recommended dosage of progesterone?
A: For
premenopausal women the usual dose is 15-24 mg/day for 14 days before
expected menses, stopping the day or so before menses.
For postmenopausal women, the dose that often works well is 15 mg/day
for 25 days of the calendar month.
Q: What
amount of progesterone do you recommend in a cream?
A: Dr. Lee
recommends the creams that contain 450-500 mg of progesterone per ounce,
which is 1.6% by weight or 3% by volume. This means that about ¼ teaspoon
daily would provide about 20 mg/day.
Q: How safe
is progesterone cream?
A: During
the third trimester of pregnancy, the placenta produces about 300 mg of
progesterone daily, so we know that a one-time overdose of the cream is
virtually impossible. If you used a whole jar at once it might make you
sleepy. However, Dr. Lee recommends that women avoid using higher than the
recommended dosage to avoid hormone imbalances. More is not better when it
comes to hormone balance.
Q: Wouldn't
it be easier to just take a progesterone pill?
A: Dr. Lee
recommends the transdermal cream rather than oral progesterone, because
some 80% to 90% of the oral dose is lost through the liver. Thus, at least
200 to 400 mg daily is needed orally to achieve a physiologic dose of 15
to 24 mg daily. Such high doses create undesirable metabolites and
unnecessarily overload the liver.
