Yohimbe bark (pronounced yoh-heem-buh) is an herbal supplement associated with anti-aging effects. It is used to naturally treat erectile dysfunction, low libido, hormonal imbalances and symptoms like low energy. Yohimbe has a long history of use in Western Africa, where the plant originates. It’s still grown there today, especially for its apparent aphrodisiac abilities.
The results, published earlier this month, show that the 80 men in the study with moderate or severe erectile dysfunction (ED) and high cholesterol reported an improvement in their ability to maintain an erection after supplementing their diet with niacin. The 80 men who took a placebo pill, who also began the study with only mild ED, did not experience a change in their symptoms, the researchers said.
Testosterone levels did not differ statistically in the treatment groups and did not change during treatment with yohimbine. The levels of dehydroepiandrosterone and free testosterone tended to be higher in the responder group, but the levels in both groups were well into the age-adjusted normal ranges. Androgens play a part in peripheral erectile activity, but they are not necessary for the central arousal stimulation of yohimbine,36 in which norepinephrine release acts as an inhibitor antagonist.2 Peripheral sympathetic stimulation also occurs37 but less than its adrenergic antagonistic activity. These peripheral effects are prompting the search for new alpha-2 adrenergic antagonists38
Using the protocol of a clinical randomized placebo-controlled parallel-group trial, the study also took place at the University of Hong Kong. One hundred sixty male patients with ED and dyslipidemia were randomized into two groups receiving either up to 1,500 mg of oral niacin daily or placebo for 12 weeks. Using questions from the International Index of Erectile Function (IIEF, particularly questions Q3 and Q4), the primary outcome was improvement in erectile function. Q3 ranked “frequency of penetration,” while Q4 ranked “frequency of maintained erections after penetration.” Other outcome measurements included the total IIEF score, IIEF-erectile function domain, and Sexual Health Inventory for Men (SHIM) score.
When a man becomes sexually excited, muscles in their penis relax. This relaxation allows for increased blood flow through the penile arteries. This blood fills two chambers inside the penis called the corpora cavernosa. As the chambers fill with blood, the penis grows rigid. Erection ends when the muscles contract and the accumulated blood can flow out through the penile veins.
It’s important to note that high levels of zinc can reduce available copper in the body and affect iron levels. High levels of zinc can also interfere with different kinds of medications. Though it is estimated that 40 milligrams of zinc supplement are safe for men to take daily, there is no long-term research into the effects that this practice could yield.