Currently, there are four orally active drugs are available to treat ED. These include: sildenafil citrate (Viagra [Pfizer, USA]), vardenafil hydrochloride (Levitra [Bayer, Germany]), tadalafil (Cialis [Eli Lilly, USA]) and avanafil (Stendra, Spedra [Vivus Inc, USA]). These drugs inhibit the enzyme phosphodiesterase type 5 (PDE-5), which is responsible for the hydrolysis of cGMP. PDE-5 inhibitors and cGMP act as effectors of dilation of smooth muscle of cavernosal bodies. PDE-5 inhibitors are contraindicated in patients taking any kind of nitrate therapy for angina, and may not be appropriate for men with certain health conditions, such as severe heart disease, heart failure, history of stroke or heart attack, uncontrolled high blood pressure or diabetes, and patients with pigmental retinopathy. PDE-5 inhibitors are less effective in men with diabetes and men who have been treated for prostate cancer. PDE-5 inhibitors are also not effective in men with retinitis pigmentosa, a genetic disease involving PDE-5 deficiency. The common side effects of PDE-5 inhibitors include gastrointestinal upset, headache, nasal congestion, back pain and dizziness. The PDE-5 inhibitors may interact with other medications including antihypertension drugs. Nonetheless, the PDE-5 inhibitors are generally safe and effective for most men. The primary mechanism of action of these drugs is through the mediation of NO. NO is one of the key molecules involved in ED. It is a short-lived, highly permeable, pleiotropic, gaseous molecule, secreted from the postganglionic cavernosal parasympathetic nerves, endothelium of the cavernosal blood vessels, platelets in the cavernosal sinuses and phagocytic cells (monocytes, macrophages and neutrophils). NO acts on platelets to inhibit platelets adhesion and aggregation. NO causes relaxation of the smooth muscle of the cavernosal blood vessels of the penis, leading to vasodilation, tumescence and stimulation. Release of NO in the corpus cavernosum of the penis during stimulation activates the enzyme guanylate cyclase, which results in increased levels of cGMP, producing smooth muscle relaxation in the corpus cavernosum and resulting in increased blood flow (5). NO is mainly produced from cavernosal nerves, which are nonadrenergic, noncholinergic nerves within the penis, and acting via its second messenger cGMP. It has been suggested that maintaining normal body weight and mild exercise, as well as dietary supplementation of folic acid, zinc, calcium, vitamin C, vitamin E and L-arginine, a precursor of NO, can support the biochemical pathway leading to NO release . NO is an effector molecule that is involved in a number of intracellular functions such as vasorelaxation, endothelial regeneration, inhibition of leukocyte chemotaxis and platelet adhesion . A small proportion of autonomic nerves do not release either Ach or norepinephrine . For example, the cavernous nerves predominantly release NO in the penis. The exact mechanism is not known, but it is believed to be through increased intracellular calcium. Another gaseous molecule produced in the corpora cavernosa is hydrogen sulphide (H2S), which is also known to be involved in erectile function . H2S activates ATP-sensitive potassium channels in smooth muscle cells. Some reports indicate that NO acts in large vessels and H2S in small vessels. A high level of tumour necrosis factor-alpha has been shown in ED patients . Although current ED therapies using PDE-5 inhibitors are safe and effective, approximately 40% of ED patients do not respond to currently available treatment [11,12]. For these patients, herbal therapy may be useful.
In addition, when research has shown a nutrient such as zinc or niacin to improve sexual function, it's usually in people who are deficient in it. So, before you stock up on over-the-counter nutritional supplements for ED, speak with your doctor. He can test you for deficiencies and steer you toward the most effective and safest way to treat your erectile dysfunction.
Ginseng (Figures 4,,55): this is an adaptogenic herb touted to have boosted the potency of Ottoman sultans. It increases the body’s ability to handle environmental stresses and combat biochemical imbalances. It energizes when one is fatigue and calms when overanxious. It also increases sex related hormones like testosterone and enhances sexual responses in men and women. It thus acts as a tonic, stimulant and aphrodisiac (4,5).
Move a muscle, but we're not talking about your biceps. A strong pelvic floor enhances rigidity during erections and helps keep blood from leaving the penis by pressing on a key vein. In a British trial, three months of twice-daily sets of Kegel exercises (which strengthen these muscles), combined with biofeedback and advice on lifestyle changes — quitting smoking, losing weight, limiting alcohol — worked far better than just advice on lifestyle changes.
Derived from the bark of a West African evergreen tree, yohimbe was the go-to ‘script for a wonky willy prior to the advent of wonder drugs like Viagra, Walker says. “Yohimbe enhances sexual performance both by blocking certain neurotransmitters in the brain and by increasing the release of nitric oxide in the cavernosal nerves of the penis,” he explains. And it pairs well with other erection-friendly tablets: A 2010 study in the Iranian Journal of Psychiatry found that a combination of yohimbe and L-arginine successfully helps guys get it up. However, yohimbe also has a handful of side effects, including elevated blood pressure and anxiety, so definitely talk to your doctor before you start on the supp.
C borivilianum (family Liliaceae) is native to India. Analysis of C borivilianum root revealed a composition of 12% to 17% saponins, 1.9% to 3.5% stigmasterol, 0.79% arabinose, 3.8% galactose, 0.73% glucose and 0.78% rhamnose . For dried root powder, the recommended dose is 5 g and the extract dose is 500 mg. It is used as an aphrodisiac and to cure ED, improve semen quality and volume. It eliminates premature ejaculation, improves general well-being and vitality, and increases stamina and libido. Visavadiya and Narasimhacharya  have demonstrated that administration of C borivilianum (0.75 g and 1.5 g root powder per rat per day for four weeks) to hypercholesteremic rats significantly increased highdensity lipoprotein cholesterol levels and decreased plasma and hepatic lipid profiles. Furthermore, the treatments also resulted in increased excretion of fecal cholesterol, sterols and bile and increased superoxide dismutase levels. Kenjale et al  evaluated the aphrodisiac and spermatogenic potential of the aqueous extract of dried roots of C borivilianum in rats. C borivilianum was given orally at doses of 125 mg/kg/day and 250 mg/kg/day. Viagra 4 mg/kg/day (sildenafil citrate) was administered as a control. Sexual behaviour was monitored 3 h later using a receptive female. Their sexual behaviour was monitored on days 1, 7, 14, 21 and 28 of treatment by pairing with proestrous female rats. For sperm count, the treatment was continued further in all groups except for the Viagra group for 60 days. At 125 mg/kg, C borivilianum had marked aphrodisiac action, as demonstrated by increased libido, sexual vigour and sexual arousal in the rats. Similarly, at the higher dose (250 mg/kg), all the parameters of sexual behaviour were enhanced, but showed saturation effect after 14 days. On day 60, the sperm count increased significantly in both the C borivilianum-treated groups (125 mg/kg/day and 250 mg/kg/day) in a dose-dependent manner. The administration of C borivilianum extract has been found to be useful for the treatment of premature ejaculation and oligospermia . Supplementation with C borivilianum root 250 mg/kg/day and 500 mg/kg/day to streptozoticin-induced diabetic male rats for 28 consecutive days improved sperm morphology, and reduced oxidative stress and formation of free radicals . In case of streptozotocin- and alloxan-induced hyperglycemia, the aqueus extracts from C borivilianum resulted in improved sexual performance compared with diabetic control [34,35].
For centuries, men have tried all sorts of natural remedies for erectile dysfunction (ED) -- the repeated inability to get or maintain an erection firm enough for sexual intercourse. But do they really work? It is simply not scientifically known at this point. Furthermore, you take these remedies at your own risk, because their safety profiles have not been established. What follows are commentaries by experts and reviews in the field of alternative treatments that are available over the counter for erectile dysfunction and impotence.
L-arginine: L-arginine is an amino acid present in the proteins of all life forms. Also, referred to as arginine, this amino acid is required to carry out the synthesis of nitric oxide, which relaxes the blood vessels and allows more blood to flow through arteries (13). L-arginine has shown promise in the treatment and prevention of cardiovascular disease and in the treatment of male infertility (13). With its anti-oxidant properties, L-arginine can be an integral part of any sexual wellness supplement.
W somnifera (ashwagandha), also referred to as winter cherry (family Solanaceae), grows in Africa, the Mediterranean, India, Pakistan, Bangladesh, Afghanistan, South Africa, Egypt, Morocco, Congo and Jordan . The roots of the plant contain steroid alkaloids and steroidal lactone, which are the main constituents of ashwagandha; these compounds are referred to as withanolides. Among the various alkaloids, withnine is the main constituent. The other alkaloids are somniferin, somnine, somniferine, withananine, pseudowithanine, tropine, pseudotropine, cuscohygrine, anferine and anhydrine. Two acyl steryl glucosides (sitoindoside VII and sitoindoside VIII) have been isolated from the root. The withanolides contain a C28 steroidal nucleus with a C9 side chain and six-membered lactone rings. Ashwagandha root also contains flavonoids and many ingredients of the withanolide class. It has several medicinal applications (aphrodisiac, liver tonic, anti-inflammatory agent, astringent), and is used to treat bronchitis, asthma, ulcers, insomnia, senility and dementia. Clinical trials and studies involving animal models support the use of ashwagandha for anxiety, cognitive and neurological disorders, inflammation and Parkinson’s disease. It also provides cryoprotective benefits to patients undergoing radiation and chemotherapy, and shows beneficial effects for nervous exhaustion. W somnifera is used as an aphrodisiac, sedative and rejuvenative, and is also used to treat chronic fatigue, dehydration, bone weakness, muscle weakness, loose teeth, impotency, premature ejaculation, debility, constipation, senility, rheumatism, nervous exhaustion, memory loss, drug withdrawal symptoms, anxiety and arthritis pain in the knee. Extracts from W somnifera inhibit transcription factor nuclear factor kappa B (NF-κB); thus, it acts as an anti-inflammatory agent. This has been attributed to its ability to interact with IKKB, a kinase that is responsible for the nuclear translocation of NF-κB and activation of inflammatory signalling pathways .
Antioxidants boost nitric oxide production and prevent NO breakdown. Ascorbic acid has direct effects on the bioactivity of NO, and augments NO production in a variety of body processes. The effects are actually synergistic with Vitamin E. Both vitamins are not usually measured, and a reasonable dose of Vitamin C is 500 to 1,000 mg daily. Vitamin E supplementation should be limited to <400 IU per day because of potential adverse long-term health effects of higher doses.
The herbal medicines used in the management of sexual impotence and erectile dysfunction are mainly prepared by pounding, chewing and boiling and are mainly orally administered. The traditional healers treat sexual impotence and ED by prescribing some of these herbs in tea or using local beers, fermented milk and porridge. Some herbs are herbs are roasted or smoked such as coffee before administration. The dispensing of herbal medicines used in sexual impotence and ED using local beers, fermented milk and porridge possibly the alcoholic content improves on the kind of active chemicals extracted than water alone12.
Shindel, A. W., Xin, Z.-C., Lin, G., Fandel, T. M., Huang, Y.-C., Banie, L., … Lue, T. F. (2010, February 5). Erectogenic and neurotrophic effects of icariin, a purified extract of horny goat weed (Epimedium spp.) in vitro and in vivo. The Journal of Sexual Medicine, 7(4), 1518-1528. Retrieved from http://onlinelibrary.wiley.com/doi/10.1111/j.1743-6109.2009.01699.x/full