Hormone replacement therapy (HRT) is any form of hormone therapy wherein the patient, in the course of medical treatment, receives hormones, either to supplement a lack of naturally occurring hormones or to substitute other hormones for naturally occurring hormones. Common forms of hormone replacement therapy include:
As recently as 2005 DFAB (designated female at birth) people have had a positive attitude towards hormone replacement therapy, but based on the empirical data, these attitudes may be overly optimistic. There is still much to learn about how HRT affects people. In the combined hormone trial, the WHI tested only one estrogen (Premarin) and one progestin (Provera), in a single pill (Prempro), at a single dose (0.625 mg Premarin and 2.5 mg Provera). Therefore, the results are not reliable nor representative.
To avoid HRT risks, it is essential to use the most effective delivery method of both estrogen and progesterone. Bioidentical estradiol (estrogen) when taken orally is converted in the liver to estrone, a weaker bioidentical estrogen. However, when estrogen as estradiol is used transdermally as a patch, gel, or pessary, it enters the bloodstream as bioidentical estradiol. When estrogen is ingested it is subjected to first pass metabolism (Phase I drug metabolism) and is processed through the liver. This first pass metabolism stimulates proteins associated with heart disease and stroke, such as C-reactive protein, activated protein C, and clotting factors. Using a patch, gel, or pessary to take estrogen avoids first pass metabolism and the risks associated with it and the same level of blood concentration can be achieved avoiding the serious side effects associated with oral estradiol HRT. Current research shows that the transdermal route of estradiol administration can also be advantageous for women with diabetes, hypertension and other cardiovascular risk factors, as those risks increase with advancing age. Women taking bioidentical estrogen, orally or transdermally, who have a uterus should still take a progesterone to lower the risk of endometrial cancer. The plant-derived progesterone creams sold over the counter contain too little progesterone to be effective. Wild yam extract creams are not effective since the natural progesterone present in the extract is not bioavailable.
Past research has highlighted potential risks of HRT. The principal results from the Women's Health Initiative Randomized Controlled Trial was that hazard rate of invasive breast cancer exceeded the stopping boundary for this adverse effect and the global index statistic supported risks exceeding benefits.
A study where women going through menopause using HRT with Progestin as a major component of the therapy showed a few negative effects on hearing, which highlights the importance of choosing bioidentical progesterone instead of synthetic progestin. Not only does the Progestin decrease the functionality of many regions of the ear it also reduces the effectiveness in parts of the central nervous system used for hearing. Also, in some situations, it has been shown that menopausal women who are caregivers and receive HRT can have an increased chance for cardiovascular issues. As caregivers, it is implied that they have more acute stress in their lives and that acute stress along with the HRT is priming negative cardiovascular effects.