How soon the drugs start working ranges from 15 to 60 minutes. Neither Viagra nor Levitra will work if you take them after a meal, which blocks their absorption. However, neither Cialis nor Stendra interact with food this way. The onset time determines how soon you can engage in intercourse. Stendra and daily-use Cialis are closest to being an "on demand" erectile drug; using the others requires more planning.
The association between low testosterone and ED is not entirely clear. Although these 2 processes certainly overlap in some instances, they are distinct entities. Some 2-21% of men have both hypogonadism and ED; however, it is unclear to what degree treating the former will improve erectile function.  About 35-40% of men with low testosterone see an improvement in their erections with testosterone replacement; however, almost 65% of these men see no improvement. 
Instant erection oils are designed to penetrate the deepest layers of the penile tissue and testicles instantaneously, and give noticeable results within 30 - 90 seconds. Because the absorption is direct to the genitals using the transdermal method, 95% of the beneficial ingredients are absorbed, compared to approximately 5 to 10% with an herbal capsule or tablet. The other benefit: it lets you be ready for anything! The last-minute nature of this product means you can use it right when you need it with nothing else to remember or take. Get an erection when you want it!
For example, many men with diabetes mellitus may develop erectile dysfunction during their young and middle adult years. Physicians, diabetes educators, and patients and their families are sometimes unaware of this potential complication. Whatever the causal factors, discomfort of patients and health care providers in discussing sexual issues becomes a barrier to pursuing treatment.
You’ve heard of—and probably experienced—the numbing effect alcohol has on your mind, body, and (unfortunately) penis. If you fail to rise to the occasion on a regular basis and you're drinking has gone from occassional weekend binge to a Monday through Friday ordeal, consider cutting back—way back. Heavy drinking proportionately increases your risk of ED, according to research from the Indian Journal of Psychiatry.