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 .
L-arginine. L-arginine is an important amino acid that the body needs to build proteins. Because L-arginine has been shown to improve blood flow, some alternative practitioners have recommended that the supplements be used to treat ED. The Natural Medicines Comprehensive Database, which is a reliable authority on alternative medicines, says L-arginine is possibly effective for treating erectile dysfunction. But Harris warns that "although this supplement could improve blood flow, side effects can be dangerous." L-arginine can cause an allergic reaction or worsen asthma in some people; it can also lower blood pressure.
Most sincere gratitude to the sponsors, Third World Organisation for Women in Sciences (TWOWS), NUFU Medicinal plants Project through Botany Department, Faculty of Science, Makerere University, UNESCO-MAB Young Scientist Research Award, 2000, Gender studies, Makerere University and WHO-Uganda. The Staff of Queen Elizabeth National Park, Field assistants, local leaders, the resource users and all respondents, particularly the TBAs and traditional healers in Bushenyi, Mbarara and Kasese Districts who provided the information.
The study was conducted between April 2000 and March 2003 in western Uganda. To collect this data indirect asking of questions and investigations that do not refer or offend anyone were used since nobody especially men can say openly that they have this problem. These methods are explained in the textbook of ethnobotany and others have been used in the field for this kind of studies in Uganda and elsewhere in the world10,12,13,14,21. These methods included visiting the traditional healers to document the indigenous knowledge (IK), regarding medicinal plants used, gender and socio-cultural aspects and where the plants are harvested. Informal and formal conversations, discussions and interviews, market surveys and field visits were conducted.
Erectile dysfunction supplements and other natural remedies have long been used in Chinese, African and other cultures. But unlike prescription medications for erectile dysfunction, such as sildenafil (Viagra), vardenafil (Levitra, Staxyn), tadalafil (Cialis, Adcirca) and avanafil (Stendra), erectile dysfunction herbs and supplements haven't been well-studied or tested. Some can cause side effects or interact with other medications. And the amount of the active ingredient can vary greatly from product to product.