Natural

Natural hormones, also referred to as bio-Identical, are considered "natural" because the original source is from a plant. Wild yam and soybean plants contain precursor molecules that can be chemically processed into steroid hormones such as progesterone, estradiol and testosterone. Patient demand for natural (bio-identical) hormones, which has consistently been addressed by compounding pharmacies, has gained the attention of some manufacturers. Bio-identical hormones now available from manufacturers include Estrace, Climara, Vivelle, Fempatch, Androgel, Androderm and Prometrium. Pharmacists licensed by their respective state boards to compound, can also formulate hormones using chemicals approved for use in the United States. Compounded dosage forms are available in transdermal creams, sublingual troches, pellet implants, suppositories, delayed release capsules or tablets and injectables. A patient using a compounded product can receive the exact amount of hormone needed instead of being locked into strengths made commercially.

Synthetic

Synthetic hormones can be patented which can allow a single company to corner the market. Beginning in the late 1800's, U.S. law allowed patenting only on products that were not natural substances. Synthetic hormones include the following; Provera (med-roxyprogesterone), Estinyl (ethinyl estradiol), Testred (methyltestosterone), Halotestin (fluoxymesterone), Prem-pro and Estratest. An example when a doctor may prefer synthetic hormones is the case of a patient with previous or family history of estrogen dependent tumors. Synthetic progestin or testosterone does not convert to estrogen once in the human body, however a small percent of natural progesterone or testosterone can convert.