For those who want to avoid estrogens in any form, phytoestrogens from plants are a consideration. A soy extract that provides at least 50 mg of soy phytoestrogens are often a key ingredient for effective natural estrogen replacement therapy. Based upon records of dietary soy consumption inJapan, where breast cancer incidence is very low, daily soy isoflavone intake has been estimated at 50 mg per day. The typical Western diet, on the other hand, only provides 1 to 5 mg a day of the soy isoflavones that may protect against several forms of cancer.
Commercial synthesis came next. In the 1930s, Austrian chemists were synthesizing male and female hormones from soybean sterols (cholesterol-like substances). This process was expensive because it was hard to separate the sterols from each other. American chemist Percy Julian (1899-1975) discovered a much easier way to separate sterols, which permitted inexpensive synthesis of both progesterone and testosterone. American chemist Carl Djerassi (1923-) is also noted for synthesizing estrone and estradiol (estrogens) from plant materials.
Many hormones and their structural and functional analogs are used as medication . The most commonly prescribed hormones are estrogens and progestogens (as methods of hormonal contraception and as HRT ),  thyroxine (as levothyroxine , for hypothyroidism ) and steroids (for autoimmune diseases and several respiratory disorders ). Insulin is used by many diabetics . Local preparations for use in otolaryngology often contain pharmacologic equivalents of adrenaline , while steroid and vitamin D creams are used extensively in dermatological practice.