We live in an era when more and more emphasis is being placed on the
importance of natural substances. Natural food supplements and herbal
formulations are in demand. Homeopathic physicians and caregivers are
gaining popularity. Everyone seems to be asking, "What can we do
to help the body repair itself in a more natural fashion?"
Many women who take hormone replacement supplements are also asking the
"natural vs. synthetic" question. Is natural always better?
What is the difference between natural micronized progesterone and the
synthetic progestin, medroxyprogesterone, also commonly prescribed as
The most outstanding difference...
between the two is that medroxyprogesterone is an analog, a "look
alike", of progesterone, not truly a progesterone at all, but rather
a progestin. The chemical structure of medroxyprogesterone closely resembles
the chemical structure of progesterone as it is produced naturally in
the human body. But, even a slight difference in the molecular configuration
of a compound can produce a totally different response from its natural
Progesterone is the oldest steroid hormonesome 500 million years
old on the evolutionary scale. All vertebrates produce progesterone, although
it is only in higher vertebrates that this hormone is instrumental in
the reproductive cycle. In lower vertebrates progesterone functions in
relation to glucose metabolism, the development of intelligence and bone
The process of producing natural progesterone, which is made from yams
and soybeans, was discovered by Russell Marker, a Pennsylvania State College
chemistry professor. While experimenting with sapogenins, a group of plant
steroids, in the jungles of Mexico in the 1930s, Marker realized that
progesterone could be transformed by chemical process from the sapogenin,
diosgenin, which is found naturally, in yams.
Unlike medroxyprogesterone, natural micronized progesterone is an exact
chemical duplicate of the progesterone that is produced by the human body.
Another immediate difference...
between medroxyprogesterone and natural progesterone is that the synthetic
hormone can actually lower a patient's blood level of progesterone. Some
women who take medroxyprogesterone to combat PMS or oppose estrogen in
menopause report headaches, mood swings and fluid retention.
On the other hand, women who take natural micronized progesterone often
say their mood swings diminish. Women who suffer from migraines as their
main complaint with PMS also find that this situation may be corrected
by natural progesterone. In its natural micronized form, progesterone
acts as a diuretic, which means the women who take these supplements may
have to go to the bathroom more frequently, but they are spared the fluid
retention and weight gain experienced by women on synthetic progestin.
Prescribed dosages also differ in regard to natural and synthetic progesterone.
Synthetic progestin is 10 to 100 times as potent as the natural progesterone.
This appears to be a tremendous range, but the doses fall well within
Medroxyprogesterone is sold in 2.5 milligram, 5 milligram and 10 milligram
tablets. For example, a woman who is using five milligrams of synthetic
progestin would find the corresponding dose of natural progesterone to
be between 50 and 500 milligrams. A dosage of 100 milligrams twice a day
or 200 milligrams per day of natural progesterone will usually produce
endometrial conversion or prevent hyperplasia.
Synthetic progestins were developed with the advent of the birth control
pill. The half life of natural progesterone was very short and researchers
were looking for an agent that would give a longer half life and yet produce
or mimic the effects of progesterone. Birth control pills contain, in
most cases, a synthetic progestin and a synthetic estrogen. The very potent
synthetic progestins prevent ovulation in a very low dose and, therefore,
accomplish their function of birth control.
Conversely, natural progesterone has been used for many years in pregnancy,
luteal phase defect and postpartum depression. When a woman is pregnant,
her progesterone levels are 30 to 50 times higher than normal. A nursing
mother should not be concerned that taking natural progesterone for postpartum
depression will affect the baby. After all, the baby has been exposed
to tremendous levels of progesterone during its development.
Significant differences exist between synthetic
and natural progesterone. Natural progesterone duplicates the
body's progesterone exactly, causes fewer side effects and can be more
consistently utilized by the body. In the case of natural progesterone
versus synthetic progestins in hormone replacement, natural does appear
to be better.
Read more questions and answers about natural hormones in the Ask The Pharmacist area of the site, or E.mail Pete Hueseman directly. A toll-free number is provided on the resources page.
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