Using some 700, mostly Jewish women as subjects, the non-surgical sterilization method developed by Clauberg consisted of introducing into female reproductive organs a specially prepared chemical irritant that produced severe acute inflammation. Within several weeks, the fallopian tubes grew shut and were blocked, and x-rays were performed to check the results.

In June 1943, Clauberg wrote:
“The non-surgical method of sterilizing women that I have invented is now almost perfected… As for the questions that you have directed to me, sir Reichsführer, on the time necessary to sterilize a thousand women in this way, I can today answer them in the way that I had anticipated: if the research that I am carrying out continues to yield the sort of results that it has produced so far (and there is no reason to suppose that this shall not be the case), then I shall be able to report in the foreseeable future that one experienced physician, with an appropriately equipped office and the aid of ten auxiliary personnel, will be able to carry out in the course of a single day the sterilization of hundreds, or even 1,000 women.”

“One of the most chilling aspects of this sordid tale is the assertion that “in the immediate postwar years, a rogues’ gallery of wanted and convicted Nazis, mass murderers who had practiced their science in notorious death camps, ended up working at Grünenthal, some of them directly involved in the development of thalidomide.” One of the most reprehensible was Otto Ambros, an inventor of sarin (the nerve gas), who had been convicted of mass murder at the Nuremburg trials but was subsequently freed. After helping the US chemical industry, he went on to become chairman of Grünenthal’s advisory committee when thalidomide was developed. Newsweek’s Roger Williams and Jonathan Stone (no relation) give further horrifying details about links between Grünenthal and other Nazi’s as well, some of whom experimented on inmates at concentration camps such as Auschwitz and Buchenwald. Another former Nazi, Heinrich Muckter, received huge bonuses for rushing thalidomide to market, despite inadequate testing.”