Since it came on the market in 1998, Viagra (sildenafil) has changed the manner in which erectile dysfunction (ED) is managed. Over 23 million men throughout the world have tried it, with a modicum of success. Even though it is the best known solution to ED, there are other options as well.
Erectile dysfunction can range from occasional to complete inability to achieve and maintain penile tumescence, or erection. An erection occurs when the nervous system activates increased blood flow to the male reproductive organ: Blood vessels relax and the influx of blood causes the tumescence. Once the sexual excitement comes to fruition, excess blood drains returning the organ to its non-erect state.
Most causes of ED are physical, including diabetes, high blood pressure, cardiovascular disease, and other conditions. It is also due to lifestyle choices such as smoking and lack of exercise. Taken together, any or all of these factors affect the blood flow to the pelvis. Other causes may include low libido and relationship or partner issues. Surgeries to treat cancers–for example, prostate cancer–and injuries to the pelvic area may result in ED. A wide array of pharmaceuticals can also lead to ED.
The three major medications to manage ED–sildenafil, verdanfil (Levitra) and tadalafil (Cialis)–are all inhibitors of an enzyme called phosphodiesterase 5 (PDES). They work by relaxing the smooth muscle cells, which increases the blood flow to the pelvic area and allows tumescence in response to sexual stimulation.
These agents are not free of side effects, however, especially for those with severe heart disease. As such, they are contraindicated for those who have recently suffered a stroke, or who take alpha-blockers for high blood pressure or voiding dysfunction. Importantly, PDE5 inhibitors should not be taken with nitrates (the heart drug nitroglycerine), because the combination can cause a potentially fatal drop in blood pressure. In addition, PDE5 inhibitors have also been linked to a rare form of blindness. All three of these inhibitors share certain side effects, including headache, nasal congestion, facial flushing, gastrointestinal distress, and, less commonly, vision changes.
Among alternatives to these PDE5 inhibitors are injectibles like Alprostadil (caverjet, Edex, MUSE). In addition, vacuum devices are used to trigger the blood flow to the penile tissue. These approaches, however, are marred by their awkwardness of use. It is for this reason that ED sufferers are increasingly turning to safer and natural alternatives. While a number of remedies are touted to be helpful, more often than not the claims fall far short of the promises.
Among the natural choices, the amino acid citrulline is one of the most effective agents to enhance blood flow without any metabolic inhibition, as is the case with PDE5 inhibitors. While PDE5 inhibitors inactivate the enzyme that breaks down nitric oxide (NO), the small molecule that induces vasodilation and increased blood flow, citrulline functions systemically to induce NO and, as a result, flush the pelvic flow with blood. Thus, by boosting the body’s ability to offset any loss in NO, citrulline is an entirely safe and effective long-term alternative for a healthy libido.






