Definition of Bioidentical

There has been controversy in recent years regarding the merits of bioidentical hormones vs. animal hormones in human hormone replacement therapies. Controversy revolves around custom treatments, wherein a doctor prescribes a combination of replacement hormones, resulting in mixtures which have not been approved by the FDA.

Bioidentical Hormones Defined

• In medicine and physiology, a "bioidentical" compound (e.g. hormones) is a laboratory-synthesized molecule whose structure is identical to a compound that the human body produces naturally. Conversely, "non-bioidentical" compounds are those molecules that, whether made in a lab or extracted directly from a non-human organism, function like human body compounds but have a different molecular structure.

How Are Bioidentical Compounds Made?

• Human estrogen and progesterone are based on a simple four-ring carbon skeleton that are common across both the plant and animal kingdom. Compounds found naturally in yams and soybeans have a specific molecular structure that allow scientists to easily convert these plant compounds into molecules that are bioidentical to forms of estrogen and progesterone produced by human cells. Even though they are produced in a lab, these plant-derived compounds are still bioidentical.

Hormone Replacement Therapy

• When the human body stops producing certain hormones (e.g. estrogen and progesterone), they can be replaced with lab-generated versions. During menopause, the female ovaries stop producing estrogen and progesterone, effectively ending the monthly reproductive cycle.
  These two hormones, however, affect body systems other than the reproductive system; when estrogen and progesterone levels drop during menopause, symptoms such as osteoporosis, hot flashes, night sweats, insomnia, lack of libido and others can arise.
  Scientists have discovered that administering lab-synthesized estrogen and progesterone can mitigate these non-reproductive-system side effects. This treatment is commonly known as hormone replacement therapy (HRT).

The Use of Non-bioidentical Compounds in HRT

• Scientists have discovered many non-bioidentical compounds produced by non-human organisms that do not require expensive laboratory synthesis. For example, it was found that pregnant horses secrete one such compound in their urine. Likewise, red clover and certain plant leaves feature non-bioidentical compounds that can bond to hormone receptor sites in humans. HRT products such as Premarin are a blend of such harvested compounds. (Because these compounds have not been chemically altered in a lab, they are technically "natural"--even though they are not bioidentical.) Critics counter that, because non-bioidentical compounds are not exact matches, these products might have more risk factors than bioidentical products.

Controversies

• Most HRT products are approved by the U.S. Food and Drug Administration (FDA), meaning that the purity and safety of a standard dose has been established and confirmed in human trials.
  More controversy about HRT arises, however, when doctors prescribe bioidentical custom compounds for their patients. These medications are prescribed to meet the individual dosage needs of each patient, and must be custom blended by specially skilled compounding pharmacists. The FDA has not approved these kind of medications, and has issued warnings about possible unforeseen risks and questionable quality.
  Compounding pharmacists, however, claim that bioidentical hormones pose less risk to patients than synthetic hormones. They say that these individualized dosages allow physicians to safely and effectively treat hormone-deficiency symptoms according to a patient's need.