If there is actual damage to the blood vessles, no miracle pill can help you if there's a leak in the 'plumbing system'.
Their effects last anywhere from a few hours to several days, depending on the brand and your own health or medical condition.
As chemical compounds, these drugs can have interactions (sometimes dangerous) with other drugs (whether prescribed or not), that can affect their efficacy and your safety, especially interactions with nitrates.
That's why they need to be prescribed by your doctor.
During the first years I noticed gradually that I can't get an rock hard erection as the previous years and my sexual libido was at history low and I always feel tired and most of the time... I have suffered from premature ejaculation my entire life.
It affected my relationship with my partner who is in her early 40s (they called it ‘the tigeress years’). ED is a thing of past and my energy level was so high I even started to do weight lifting, can't you believe it I have been suffering from urinary problems for sometimes now. But after taking 3 boxes of Rigirx, my urination function is back to normal again and I don't have to rely on Viagra anymore...thanks to Rigirx in 2005, I also noticed after some time feelings urgency to urinate but when I went to the bathroom, little more than a trickle would appear.
The chances of a fast acting stimulant having a positive effect on you alone is low.