After preliminary subjective success in a pilot study using oral treatment with ginkgo biloba extract for erectile dysfunction, these investigators organized a double blind randomized study in patients with suspected vascular-related impotence. At the start of the trial, 32 men received a standardized diagnostic work-up. Then they were either given 240 mg of ginkgo biloba extract per day or placebo. The researchers examined 23 patients after a 24-week treatment cycle. Nine patients had dropped from the study. They said: "In contrast to an uncontrolled pilot study, a placebo-controlled, double blind evaluation could not prove any benefit from treatment with oral Ginkgo biloba extract for patients with erectile dysfunction."