Progesterone comes in many forms. The most widely used forms are “synthetic” or not identical to the type of progesterone that our body makes. Most of these have pharmaceutical branding and are FDA-approved, which means they have been well studied and have clearly described progesterone effects on the body. Their risks and benefits are well elucidated. They are, however, not identical to the progesterone that our body naturally produces. Micronized progesterone or USP progesterone is bioidentical (often termed “natural” which is a misnomer as it is synthesized in a lab just like the other progesterones). Although there is a debate over whether bioidentical hormones are safer, bioidentical or micronized USP progesterone do seem to have fewer nuisance side effects associated with it.
Many perimenopausal women who are not ready to commit to full hormone replacement therapy will try OTC progesterone creams. An effective progesterone cream can really relieve many perimenopausal symptoms, but the problem is that most consumers do not know exactly what they are getting. “Wild Yam” creams are made out of the precursor hormones that are used to make many of the bioidentical and synthetic hormones; however, applying this cream to your skin does not reliably increase your progesterone levels. These creams will not work.
There are some OTC creams that actually do have pharmaceutical-grade USP micronized progesterone in them. In the past, it has been thought that the levels in these OTC creams were not significant, but some studies have shown that they actually do have significant amounts of progesterone in them. These creams are not, however, FDA regulated because they are considered cosmetic or beauty items. Because they really do increase circulating progesterone levels, they will often work and women will use them in an unregulated manner. My recommendation is that if you are considering using a progesterone cream that you discuss it with your physician ahead of time.
What Are the Risks of Hormone Therapy?
For most women in their 40s whose bodies are still making estrogen and progesterone themselves, adding a little progesterone will most likely not have any long-term effects. However, we know from the Women’s Health Initiative study in postmenopausal women on combined synthetic estrogen and progesterone that there are increased risks of heart attack, stroke and breast cancer. These risks are low enough that we still routinely prescribe these therapies to women who are suffering from menopausal symptoms – but the risks are a sober reminder that hormones can have long-term effects.
If a woman is taking progesterone and estrogen together, she should take an FDA-recommended dose of progesterone in order to counter the risks of taking estrogen. The recommendation on taking combined systemic hormones by the American College of ObGyn is that you take the lowest dose for the least amount of time to transition you through the symptoms. Short-term use of supplemental progesterone is reasonably safe but it is best to use it after discussing it with your physician.