Bio-identical Hormones: What's the deal!
Monday, January 5, 2009 at 02:26AM What are bioidentical hormones?
Bioidentical hormones, also known as human identical hormones, are typically derived from plant sources, but are identical in structure and function to human hormones. Moreover, bioidentical hormones are not chemically altered.8 Bioidentical hormone therapy is tailored to a patient’s symptoms and needs, and therapeutic bioidentical compounds typically consist of a combination of any of the following: estrone, estradiol, estriol (the three forms of endogenous estrogen), progesterone, and testosterone.3
What are the differences between bioidentical hormone therapy and traditional hormone therapy?
First, traditional hormone replacement therapy generally includes products that are derived from horse hormones and therefore do not function identically to human hormones.4 Consequently, traditional—or ‘synthetic’—hormones may create some adverse reactions in the body. For example, the synthetic progestin portion of traditional hormone therapy may cause many uncomfortable side effects, including bloating, breast tenderness, and irregular bleeding.2
Another difference between the therapies is that bioidentical hormones are tailored to each individual patient instead of being manufactured in standardized dosages.3 Bioidentical hormone therapy entails an initial assessment of each patient’s symptoms, needs, and hormone concentrations before prescribing hormones so that the therapy can be individualized to best meet the patient’s needs.
Also, there may be differences in long-term effects on health between bioidentical and traditional hormones. One French study assessing the association between hormone replacement therapy and the risk for breast cancer in postmenopausal women found that the risk was significantly greater with therapies containing synthetic progestins than with therapies containing bioidentical progesterone.2 However, more research needs to be conducted before drawing conclusions about the comparative safety of bioidenticals and synthetics. While bioidentical hormones may have fewer uncomfortable side effects, most studies have not found them to be any safer than traditional hormones.1
Finally, you may find the following terminology helpful when trying to navigate the literature on hormone replacement therapy: Progesterone is a single molecular structure that is identical to that made by the body; Progestogens are natural and synthetic hormone molecules that act like progesterone in the uterus; and Progestins are synthetic progestogens.2
What are the benefits and risks of bioidentical hormones and traditional hormone therapy?
Probably the most reliable benefit demonstrated, bioidentical hormones have been shown to help maintain bone density in women and decrease premenopausal and menopausal symptoms such as hot flashes, night sweats, fatigue, mood instability, vaginal dryness, and low libido.3
Some studies suggest that progesterone may be effective in preventing and treating neurodegenerative diseases, promoting repair processes, and preserving cognitive function with age. Synthetic progestins do not have the same effects on the brain.2
Estrogen, though not shown to improve memory or cognitive function, does improve blood flow to the brain, and stimulates the release of serotonin and norepinephrine, both of which improve nerve cell function and mood. However, using estrogen alone is linked to an increased risk for dementia in women age 65 or older (women who use combined synthetic hormone therapy have an even higher risk for dementia).2 For this and other reasons, many doctors suggest that bioidentical estrogen and progesterone always be prescribed together to maintain hormone balance and synergy.2
Progesterone has been shown to reduce the risk for atherosclerosis, and current research identifies bioidentical hormones—particularly progesterone—“as the hormone therapy of choice to support vascular function.”2 Even so, the American Heart Association recommends that hormone replacement therapy not be prescribed solely for cardiovascular protection.4
Estrogen therapy, oopherectomy (ovary removal), and menopause can all reduce testosterone levels in the body. Researchers have determined that transdermal (skin patch) testosterone improves sexual function and psychological well-being in women who have had their ovaries removed.4 Testosterone therapy can also reduce bone loss.2
Unfortunately, bioidentical estrogens have been linked to increased risk for breast cancer. Indeed, high levels of any estrogen (even naturally-occurring estrogen) in the body have been associated with increased risk for breast cancer.1 Also, estrogen replacement therapy increases the risk for blood clots, high blood pressure, and stroke, especially in women who are already more susceptible to these outcomes.2 Research also shows that estriol, the ‘weakest’ of the three endogenous estrogens, may be safer than estrone or estradiol, but still increases the risk of malignant cell activity in the endometrium and breast when given in high doses.2
As for synthetic hormones: The National Institutes of Health launched the Women’s Health Initiative (WHI) in 1991 to study the risks and benefits associated with long-term hormone use. The study was terminated early when ongoing results showed that estrogen in combination with progestin increased a woman’s risk for breast cancer, coronary events, stroke, and blood clots. No bioidentical hormones were used in the study. On a more positive note, the WHI study also demonstrated the benefits of traditional hormone therapy: decreased risk for hip fracture, decreased risk for colon cancer, and relief of menopausal symptoms like hot flashes and vaginal atrophy.2
A final caveat: women who are not eligible for traditional hormone replacement therapy, and those with a history of breast cancer or thromboembolic events should not use bioidentical hormone therapy.4
How and where can I get bioidentical hormones?
You should visit your physician before beginning any bioidentical hormone therapy. Your doctor will assess your needs, symptoms, and hormone concentrations in order to devise the best possible therapeutic plan for you.
Many bioidentical hormone products are prepared in compounding pharmacies, which are not regulated by the FDA; consequently, these products may vary in quality and potency.1 To find reliable compounding pharmacies, check with the Professional Compounding Centers of America (PCCA) or the International Academy of Compounding Pharmacists (IACP).4
Also, beware of over-the-counter progesterone creams available in health food stores and other retail outlets. The types and concentrations of progesterone in such products vary greatly, and in some cases the product may not contain any active drug whatsoever. Many over-the-counter products contain much lower doses of progesterone than those found in prescription drugs, and therefore may not be effective at all. So be careful about self-treating with hormone therapy.8
Finally, Estradiols such as Estrace, Climara patch and Vivelle-Dot patch, and the natural progesterone, Prometrium, are bioidentical estrogen and progesterone that are commercially available and FDA-approved hormone therapy products.6
What about bioidentical hormones for men?
Andropause, also known as androgen decline in the aging male (ADAM) or ‘male menopause’, refers to the gradual decrease in testosterone levels that many men experience as they age.5 In men, testosterone peaks around 19 years of age and linearly declines 1% per year thereafter. The testosterone decline usually becomes noticeable in mens’ 40s, and symptoms appear in their 40s and 50s. 7 About half of men age 80 and older have low testosterone. In contrast, some men will maintain normal testosterone levels throughout their lifetime.5 Persistent low libido, low energy, depression, and erectile dysfunction (ED) even after instituting ED medication may point to andropause.7 Other signs and symptoms of low testosterone may include: swollen or tender breasts (gynecomastia), small or shrinking testes, loss of body and pubic hair, hot flashes and sweats, mild anemia, and sleep apnea. 5
Not all men with low testosterone levels experience signs and symptoms, and signs and symptoms can vary greatly among men who do show them. Some signs and symptoms may also be due to normal aging, and the only way to determine whether a man has low testosterone levels is through blood tests.5
Testosterone replacement has been found to improve erectile dysfunction, mood, muscle strength, muscle mass, cognition, and bone density.7 However, treatment of low testosterone levels with testosterone replacement therapy remains controversial because the benefits of the therapy are not totally clear, and testosterone supplementation may increase the risk for prostate cancer. Additionally, testosterone replacement therapy may be especially dangerous for men with existing prostate cancer and heart disease. Studies also show that testosterone therapy causes sleep apnea in some men.5 Finally, oral testosterone may worsen the lipid profile, and should not be used for replacement therapy.7
Men on testosterone replacement therapy should undergo regular blood pressure and prostate monitoring. A prostate-specific antigen (PSA) test should be done yearly and the patient sent for prostate biopsy if the PSA increases more than 1 ng/mL in a year.7
References
1Adriane Fugh-Berman, MD and Jenna Bythrow, MS candidate. “Bioidentical Hormones for Menopausal Hormone Therapy: Variation on a Theme.” Journal of General Internal Medicine. Volume 22(7), July 2007, p 1030–1034.
2Deborah Moskowitz, ND. “A Comprehensive Review of the Safety and Efficacy of Bioidentical Hormones for the Management of Menopause and Related Health Risks.” Alternative Medicine Review. Volume 11(3), 2006, p 208-223.
3Lisa A Boothby and Paul L Doering. “Bioidentical Hormone Therapy: a Panacea that Lacks Supportive Evidence.” Current Opinion in Obstetrics and Gynecology. Volume 20(4),August 2008,p 400–407.
4Laura Francisco. “Is bio-identical hormone therapy fact or fairy tale?” Nurse Practitioner. July 2003.
5“Male menopause: Myth or reality?” MayoClinic.com
6Sandhya Pruthi, MD. ”Bioidentical hormones: Are they safer?” MayoClinic.com
7Susan Simmons Holcomb, ARNP, BC, PhD. “Andropause in the Aging Male Patient.” The Nurse Practitioner. Volume 32(12),December 2007,p 5–7.
8Wendy Wetzel. “Micronized progesterone: A new option for women's health care.” Nurse Practitioner. May 1999.
Janice M Vaughn MD