There are many choices when it comes to hormone replacement, and information you find on the internet can be confusing.
Let’s define some terms that are often used:
Bioidentical: Bioidentical hormones have the same chemical structure as hormones produced in the body by endocrine organs. Bioidentical hormones can be branded, or can be compounded by a pharmacist.
Compounded: a compounded hormone is made by a pharmacist according to a doctor’s prescription. The pharmacist takes estrogen or progesterone, usually synthesized from yams or soy, and mixes into the product requested. This can be provided in creams, gels, or capsules.
Estrogen and progesterone can be mixed with testosterone and DHEA.
Natural: generally a term not used in medical parlance, but meant to signify a drug that comes from a biologic source
Transdermal: There are benefits to using hormones that are absorbed directly into the bloodstream, and when hormones are applied to the skin, or placed in the vagina, they are absorbed directly into the bloodstream. When estrogen is ingested via the stomach, it passes through the liver. In the liver, coagulation factors are synthesized, and these can increase the risk of blood clots, strokes, and heart attack.
Synthetic: a substance made in the laboratory which has the chemical structure that mimics the hormone it is meant to replace. Norethindrone is a progestin which is used in oral contraceptives and is a type of progesterone.
SERM’s: Selective estrogen receptor modulators
This is an exciting and promising development in hormone research. Scientists learned the structure of the estrogen receptor and how it varies in different tissues of the body. The estrogen receptor is the site on the cell that accepts the hormone, and initiated the function that is required. For example, there is an estrogen receptor on the bone, and raloxifine is a SERM that attaches to the receptor and prevents bone loss, as estrogen would. The good news for this
drug is that it does not act as estrogen in the breast, or in the uterine lining. Therefore, there is no increase in endometrial cancer, and there is actually a decrease in breast cancer, as this drug acts as an anti-estrogen in the breast.