Research Outline

Bioidentical Hormone Replacement Therapy


To understand mainstream medical research regarding the effectiveness and potential side effects of bioidentical hormone replacement therapy for women and men in order to guide personal health decisions.

Early Findings

Our background research on bioidentical hormone replacement therapy revealed insights. Here are key pieces of information we found:

Bioidentical Hormone Replacement Therapy Overview

  • Bioidentical hormones are man-made hormones that are very similar to the hormones produced by the human body. Common hormones that are matched are estrogen, progesterone and testosterone that are used as treatment for men and women whose own hormones are low or out of balance.
  • Some prescription forms of bioidentical hormones are pre-made by a drug company, and The US Food and Drug Administration (FDA) has approved a number of preparations of bioidentical estradiol and progesterone, which are molecularly identical to the structure of the hormones generated by the human body. They have been through testing for safety and purity to be sure each dose has the same amount of hormones.
  • Other forms are custom-made by a pharmacist based on a doctor’s order that is called compounding. The compounded forms have not been tested and approved by the FDA. Customized bioidentical hormones are often advertised as being a safer, more effective, natural, and an individualized alternative to conventional hormone therapy. However, these claims remain unsupported by any large-scale studies.
  • There have been medical trials for the bioidentical hormone therapy combination of estradiol and progesterone that have resulted in the FDA approving this therapy as being safe and effective for treating moderate to severe vasomotor symptoms associated with menopause.
  • However, the lack of any well designed large-scale studies for compounded bioidentical hormone therapy continues to also mean a lack of evidence to support claims of effectiveness or superiority in the effectiveness of compounded bioidentical hormones over conventional menopausal hormone therapy.
  • It has been shown in research studies that there is an increased risk for women of blood clots, stroke, and gallbladder disease and an increased risk of heart disease and breast cancer for women who are older and who use hormone therapy (HRT) for an extended period. Many doctors who use bioidentical hormones claim they are safer than regular HRT, but there have been no large-scale research studies of bioidentical hormones to verify that they really reduce the risk of these problems.
  • Side effects can occur when a dose is first given because the body is not used to the new level of hormones. Some side effects can be linked to a certain hormone in the mixture, and many side effects get better as the body adjusts to the new level of hormones. Some common side effects include: weight gain, blurred vision, tiredness, acne, increased facial hair (women), headaches, breast tenderness, spotting, cramping, bloating, mood swings, and indigestion.