Doctors refer to a synthetic hormone, such as progesterone, as bioidentical when it has the same molecular structure of the hormone produced by the human body, according to Harvard Health. Bioidentical does not mean "natural"; as a matter of fact, it is usually synthetic, meaning it is made in a lab. Many natural progesterones, such as those taken from horses and plants, are not bioidentical to human progesterone. Scientists hope that women who take bioidentical progesterone will gain all the benefits of hormone therapy without some of the associated risks.
Beneficial Effects
According to the Mayo Clinic, progesterone may be prescribed to women of reproductive age for several reasons. The hormone can regulate the menstrual cycle and help a woman become pregnant. It may also be prescribed to help a woman maintain a pregnancy when her body does not produce enough progesterone on its own. Women with endometriosis--overgrowth of the uterine lining--may take progesterone to manage pain.
Older women going through menopause experience a drop-off in their progesterone production. Because of this, they experience symptoms such as sleeplessness, hot flashes and loss of bone-density, according to Harvard Health. Menopausal women may try hormone replacement therapy with progesterone to alleviate the symptoms of menopause. Hormone replacement therapy typically reduces instances of hot flashes and sleeplessness and protects against osteoporosis.
Harmful Effects
Progesterone therapy has many negative side effects, according to the Mayo Clinic. Even though it protects against osteoporosis in the long run, it can initially cause bone thinning and should not be taken by smokers or drinkers, who have a higher risk of bone loss. Progesterone commonly causes tenderness, swelling and bleeding of the gums, as well as the more serious side effects of blood clots, heart attacks, stroke, and liver and eye problems. Blood clots are of serious concern because they can initiate any of several more dangerous conditions. Any woman who takes progesterone and experiences a migraine, speech, coordination or vision problems, numbness or pain in the chest, arm or leg or an unexplained shortness of breath should consult a doctor immediately. Progesterone may also cause changes in vaginal bleeding and blood sugar irregularities; symptoms of which include dry mouth, frequent urination, loss of appetite and extreme thirst. Less common side effects include psychological depression, skin rashes and unexpected lactation.
Comparative Effects to Non-Bioidentical Progesterone
A 2006 metastudy on the safety and efficacy of bioidentical hormones was conducted by Dr. D. Moskowitz and published in "Alternative Medicine Review." In his survey of the research done on bioidentical progesterone, he found that it had the same positive effects as non-bioidentical progesterone, but had reduced risks of blood-clotting, liver problems and breast cancer associated with it. Dr. Moskowicz concludes that, given the option, women should choose bioidentical progesterone above other types.
