Are Progesterone Creams the Natural Alternative?
For: HRT—What Are
Your Alternatives?, January 2003
We get many letters from readers about natural progesterone
creams. Do they help relieve premenstrual syndrome (PMS)? Menopausal symptoms?
Do they work as well as hormone replacement therapy? Here are the (relatively)
short answers.
Manufacturers and promoters claim that "natural"
progesterone skin creams, sold in health-food stores and drugstores and
on the Internet without a prescription, can treat or prevent menopausal
problems such as hot flashes, depression, vaginal dryness, and bone loss,
as well PMS in younger women. This progesterone has been dubbed "natural"
because it’s synthesized from wild yams or soybeans and is a chemical
match for progesterone produced by the ovaries. In contrast, the progesterone
that’s part of hormone replacement therapy (HRT) is a synthetic form
called progestin, engineered so that it can be taken in a pill and won’t
break down before it enters the bloodstream.
Women who don’t want to take HRT sometimes try these
creams instead, and some report good effects. But studies show that these
creams do not raise blood levels of progesterone enough to produce the
claimed effects (even when the creams are applied at doses far higher
than recommended on the labels). Moreover, most studies have found that
neither natural progesterone nor progestin (usually given by mouth or
as vaginal suppositories) helps with PMS.
The creams are registered with the FDA as cosmetics, not
drugs, so regulation of the contents and the claims is minimal. There’s
no way to know how much progesterone, if any, is in any of these products.
The main danger of these creams is that some women may believe
they can use them as an alternative to progestin as part of HRT. Progesterone—or
progestin—is a crucial part of HRT, because it counters the potential
cancer-causing effects of un-opposed estrogen on the uterus. The skin
creams will not protect the uterus from estrogen’s effects.
Note: Natural progesterone
does come in prescription forms— orally (Prometrium), an intravaginal
gel (Crinone), and an intra-uterine device (Progestasert). These drugs
may be good alternatives for progestins and have fewer side effects. One
new study found that about two out of three women reported more relief
from menopausal symptoms after switching to oral natural progesterone
from their previous hormone replacement regimen (with progestins). An
additional benefit of the natural progesterone pill is that it does not
reduce estrogen’s ability to raise HDL (good) cholesterol as much
as progestins.
UC Berkeley Wellness Letter, April 2002
