Wild oats: a study in 1986 by the Institute for Advanced Study of Sexuality in San Francisco reported effects like heightened sexual awareness, increased sexual thoughts, more orgasms (36% in men and 29% in women) and some male subjects showed increased levels of testosterone attributed to unbinding of testosterone from TBG. Oats supply steroidal saponins which modulate hormonal balance (5).
DHEA. DHEA, or dehydroepiandrosterone, is a natural hormone that the body uses to make the male hormone testosterone. DHEA and testosterone decrease with age, just as ED increases with age, so it seems that taking DHEA might protect against ED. But Harris says that "it is unlikely that taking DHEA would raise your testosterone enough to make much difference." DHEA should not be used by people with liver problems; it also has many side effects.
Feeling fatigued, very stressed, depressed or dealing with another mood-related issue that can lower libido. Sources of stress and diminished quality of life — such as “deteriorating economic position,” unhappiness with one’s job or other aspects that lower emotional health — are believed to be major causes for sexual dysfunction in both men and women
In diabetes, vasoconstrictors and vasoactive factors are increased in addition to structural changes and attenuation of relaxation responses in the corpus cavernosum. A shifting of the balance of vasoactive factors occurs such that relaxation factors (eg, nitric oxide [NO]) are inhibited and contractile factors are induced in microvascular disease. With epidemiological predictions suggesting that the incidence of diabetes mellitus will increase to 300 million by 2025, management of diabetes-induced ED is increasingly important.
Gingko biloba: this is an example of a tonic herb that equilibrates our body systems. When tired it energizes and when stressed it relaxes the individual. It increases blood circulation which better prepares the male for the heart-racing excitement of sex. Early reference to its medicinal use was in 2900 BC Chinese Materia medica which believed it increased sexual energy. Gingko’s circulation enhancer called terpene lactone increases cerebral as well as genital blood flow and its significantly increased production of dopamine, adrenaline and other neurotransmitters in the brain improves pleasure arousal and alertness (5).

Yohimbe A number of clinical trials have shown that the primary component of this bark from an African tree can improve sexual dysfunction associated with selective-serotonin reuptake inhibitors (SSRIs) used to treat depression. This herb has been linked to a number of side effects, including increased blood pressure, fast or irregular heartbeat, and anxiety. Yohimbe shouldn't be used without a doctor's supervision.