by John R. Lee, M.D. and Virginia Hopkins
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
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
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
Q: Why would a premenopausal woman need
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
Q: Where should I put the progesterone
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
Q: What is the recommended dosage of
A: For premenopausal women the usual dose is
15-24 mg/day for 14 days before expected menses, stopping the day or so before
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
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
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.
Q: Where can I get more information on
progesterone and natural hormone balance?
A: For a detailed explanation of women's
hormone balance issues, a hormone balance program, as well as detailed descriptions of how to use natural progesterone, the following books by John R. Lee, M.D. are recommended:
What Your Doctor May Not Tell You About Menopause
What Your Doctor May Not Tell You About PREmenopause
What Your Doctor May Not Tell You About Breast Cancer
Click here for more about these books including sample chapters and purchase