In the late 1950s to the early 1960s, a drug called thalidomide was put on the market by the German pharmaceutical company Chemie Grünenthal, who discovered the chemical accidentally while attempting to find an inexpensive way to manufacture antibiotics. After some testing on animals, who were subjected to extremely high doses of the drug, the company concluded that the drug was harmless and had no side effects. They were wrong.

Chemie Grünenthal began distributing free samples of the drug in 1955 without further research or clinical trials done on the drug. Epilepsy patients began taking thalidomide to prevent seizures, and they reported experiencing deep sleep and calming and soothing effects after taking the drug. Other side effects were reported but these were dismissed as negligible. On October 1, 1957, doctors in West Germany began prescribing thalidomide user the brand name of Contergan to their female patients to combat the nausea and vomiting coupled with insomnia associated with morning sickness during pregnancy. Its use gradually spread worldwide, selling under a variety of brand names such as Distaval Asmaval, Distaval Forte, Tensival, Valgis, Valgraine and others. Thalidomide was also marketed as a powerful hypnotic sedative.

Pregnant women began reporting certain side effects while taking the drug, such as sleepiness, drowsiness, constipation, skin rash, severe headaches, stomach aches, peripheral neuropathy (numbness and pain in your arms, hands, legs and feet), nausea and vomiting, giddiness or nervousness at higher doses, shivering, buzzing in the ears, depression or mood-swings, and a general sense of illness. Within a year, women who had taken the drug during pregnancy began reporting the births of babies with a myriad of birth defects, more commonly phocomelia, which presents itself in short, malformed, flipper-like arms and legs. Other birth defects include missing limbs, incomplete fingers or toes, fused appendages, deafness, blindness, disfigurement, cleft palate,and malformations of the eyes and ears, heart, genitals, kidneys, digestive tract (including the lips and mouth), and nervous system. In some cases the mothers had only taken one thalidomide tablet; it was later determined that a single dose can have disastrous side effects on a fetus especially when taken at a critical point within the first trimester of pregnancy. This is because the drug is a teratogen, causing congenital deformities as it passes through the placental barrier between mother and fetus.

Initially, Chemie Grünenthal refused to acknowledge the growing number of cases of thalidomide deformities and deaths in newborn babies; however, its disastrous side effects were gaining widespread media attention. Articles in several highly regarded medical journals began detailing the drug's numerous side effects. In the United States, the drug had been repeatedly denied approval by the Food and Drug Administration (FDA). The officer in charge of the application, Frances Kelsey, felt that there was not enough data on thalidomide's teratogenic effects based on her earlier work on the effects of a drug called quinine. Kelsey wanted more extensive studies on its effects on human metabolism especially during pregnancy, as well as the drug's chemistry, pharmacology and stability from Richardson-Merrell, the pharmaceutical company waiting for FDA approval for the sale of thalidomide under the name Kevadon.

By the time thalidomide was withdrawn from markets worldwide, it was too late for the victims and families affected by this medical disaster. It has been estimated that some 10,000 infants were born with deformities as a side effect of the drug, with about half of that number or less surviving into adulthood because of the high mortality rate among victims.