Diethylstilbestrol (DES) is a synthetic, nonsteroidal estrogen that was previously used in medical treatments and as an additive in livestock and poultry feed. It has a complex history marked by therapeutic uses and later, significant health concerns.
Diethylstilbestrol was first synthesized in 1938. During the mid-20th century, DES was commonly prescribed for a variety of conditions in women, ranging from suppressing lactation to preventing miscarriages. Its use in animal feed aimed to promote growth and improve meat production.
The primary medical application of DES was to prevent complications during pregnancy. It was believed that by supplementing estrogen, miscarriages, and premature deliveries could be minimized. However, subsequent research showed that DES was ineffective for this purpose.
In agriculture, DES was used as a growth-promoting agent in livestock and poultry feed. The estrogenic properties of DES were believed to enhance meat production by accelerating weight gain and promoting the deposition of certain fats.
By the early 1970s, it became evident that prenatal exposure to DES increased the risk of a rare form of vaginal cancer known as clear cell adenocarcinoma in daughters of the women who took DES. Further studies also revealed that DES was associated with increased risks of breast cancer, infertility, and other health issues in both the women who took it and their offspring.
Consequently, the FDA in the USA and its counterparts in many other countries banned the use of DES in pregnant women. The use of DES in animal feed was also phased out.
The use of DES in both human medicine and animal agriculture has significantly diminished due to associated health risks. Today, DES serves mainly as a case study in pharmaceutical regulation and the importance of rigorous drug testing.