In 1938, Dodds and his co-workers in England published a series of articles on their six year study of synthetic estrogenic hormones related to the stilbenes and diphenylethane. They introduced stilbestrol which produces an even stronger effect in animals than the naturally occurring estrogens. Stilbestrol is the parent substance from which have been developed the other closely related synthetic substances in an attempt to reduce the toxic effects of stilbestrol. The compound 4: 4 dihydroxy alpha beta diethylstilbene is referred to in current literature under the name of stilbestrol. It was used experimentally in 1939 and appeared on the American market in 1940.