As previously explained, the active ingredients in Viagra and the other oral ED medications are designed to temporarily restore erectile function in men who are suffering from insufficient blood flow to the penis.
This is by far the most common cause of ED, but it’s not the only cause. If your impotence has its origin in emotional or mental issues and not vascular insufficiency, then it’s unlikely that Viagra will work for you regardless of when you take it.
The same is true of ED that’s caused by traumatic or congenital injury to the blood vessels that supply the male genitals. However, if your erection problems are caused by compromised blood flow to the penis because of atherosclerosis or other physiological causes, Viagra’s active ingredient should kick in as early as 30 minutes after you take it.
If you haven’t responded within 60 minutes after taking the drug, it is possible that the drug won’t work for you. If you’ve tried the drug two or three times without success, you might want to explore other treatment options with your doctor.