Yohimbine is the principal alkaloid of the bark of the West African evergreen P johimbe (formerly known as C johimbe), family Rubiaceae. The main active chemical present in P johimbe bark is yohimbine hydrochloride (an indole alkaloid), which has stimulant and aphrodisiac effects. However, the levels of yohimbine that are present in P johimbe bark extract are variable and often very low. Therefore, although P johimbe bark has traditionally been used to treat ED , there is insufficient scientific evidence to form a definitive conclusion in this area. It is an antagonist of α2-receptors and has no direct relation to erection. It acts as a sex motivation stimulant. Yohimbine has been used as both an over-the-counter dietary supplement in the form of an herbal extract, and as a prescription medicine in purified form for the treatment of sexual dysfunction. Yohimbine 20 mg or adjusted dose has been found to be effective in the treatment of orgasmic dysfunction. Yohimbine was recently associated as a treatment for type 2 diabetes mellitus in animal and human models carrying polymorphisms of the alpha-2A adrenergic receptor gene . The National Institutes of Health states that yohimbine hydrochloride is the standardized form of yohimbine that is available as a prescription medicine in the United States, and has been shown in human studies to be effective in the treatment of male impotence. Yohimbine hydrochloride USP has been used to treat ED. Controlled studies suggest that it is not always an effective treatment for impotence, and evidence of increased sex drive (libido) is anecdotal only. It cannot be excluded that orally administered yohimbine can have a beneficial effect in some patients with ED. The conflicting results available may be attributed to differences in drug design, patient selection and definition of positive response. Yohimbine has been shown to be effective in the reversal of sexual satiety and exhaustion in male rats, and has also been shown to increase the volume of ejaculated semen in dogs, with the effect lasting at least 5 h after administration. Yohimbine has also been shown to be effective in the treatment of orgasmic dysfunction in men, and has also been used for the treatment of sexual side effects caused by some antidepressants, and female hyposexual disorder. Yohimbine has significant side effects, such as anxiety reactions. Higher doses of oral yohimbine may create numerous side effects, such as rapid heart rate, high blood pressure, overstimulation, insomnia and/or sleeplessness. More serious adverse effects may include seizures and renal failure. Yohimbine should not be consumed by individuals with liver, kidney or heart disease, or psychological disorders. The therapeutic index of yohimbine is low; the range between an effective dose and a dangerous dose is very narrow. Side effects include gastrointestinal upset, increased blood pressure, headache, agitation, rash, tachycardia and frequent urination .
In addition, this amino acid increases sperm volume and makes sperm quality better. Moreover, L-Arginine is most effective for men with initially low NO levels. Thus, this amino acid normalizes endothelial nitric oxide synthesis. That contributes to the vascular function restoration, including penile vascular function. The amino acid prevents aging changes in the blood vessels and dramatically reduces the harmful effects of nicotine on arteries with capillaries.
Much of the evidence shows high rates of vitamin D deficiency in patients with erectile dysfunction. In fact, one study of 3,400 participants found that men with vitamin D deficiency were 32% more likely to have trouble with erections when all other risk factors were controlled for. It’s a little on the nose that you need vitamin D for your “D,” but hey—science can be funny too.
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.