Many antidepressants (mainly selective serotonin-reuptake inhibitors) have the uncomfortable side effect of sexual dysfunction.

An uncontrolled trial used Ginkgo biloba extract (60-240 mg/day) for 4 weeks and found improvement in 91% of women experiencing sexual dysfunction induced by antidepressants. Ginkgo had a positive effect in sexual desire, excitement (erection and lubrication), orgasm and resolution (afterglow). No adverse effects were reported and Ginkgo did not interfere with antidepressant treatment.

It is not clear exactly how Ginkgo reduced sexual dysfunction. Some Ginkgo constituents may have a potent effect on vascular smooth muscle and improve blood flow to the corpus cavernous area in the brain which is thought to be helpful for erectile dysfunction. In general it increases cerebral and peripheral blood flow which may explain how this herb became known for its benefits in preventing dementia and helping cognitive function. 

Some evidence shows that Ginkgo extract reduces stress induced rises of certain stress chemicals including Cortisol. This may be one of the main factors that improve sexual libido in women. 

Reference:  Cohen AJ, Bartlik B. Ginkgo biloba for antidepressant-induced sexual dysfunction. J Sex Marital There 1998: 24: 139-143.