For men with intimacy problems, most will turn to that infamous little blue pill.
Erectile dysfunction affects almost half the male population over the age of 40 - whether caused by medication, poor blood flow to the penis or drinking too much alcohol.
For years, Viagra has been the most popular solution.
But while its function is well-known, the average person's knowledge of how it works is limited.
A study conducted by the company Superdrug, however, has revealed what the pill actually does to your penis in the minutes and hours after taking it.
First 12 minutes
In this time period, the drug is rapidly absorbed by the body and some will get an erection very quickly.
In the vascular system, cGMP - a nucleotide - causes the walls of blood vessels to relax and dilates them so blood can flow easily. The drug is currently making its way into the blood vessels.
One study of men with erectile dysfunction (ED) found that they could get an erection from Viagra as fast as 12 minutes after taking a dose, although it was unclear whether or not this was an effect from the drug.
27 minutes
If there are no changes after the first 15 minutes, an erection will usually occur in about half an hour.
In this period, the drug binds to the PDE5 enzyme that breaks down cGMP and reduces blood flows.
The binding prevents breakdown from occurring. A greater amount of cGMP is available in the blood vessels which lets blood flow to the penis.
The average response time to by Viagra is 27 minutes.
But researchers say to remember that it's just
an average and that individual response depends on any number of personal physiological traits.
57 minutes
This period is when Viagra has reached its 'maximum erection' potential.
The medication reaches its highest blood concentration, which is why it's recommended to take the pill between one-half to one hour before you want to have sex.
In one study, men reported being able to achieve erections lasting an average of 33 minutes
an hour after taking Viagra,
Four hours
For every four hours that the drug stays in your body, the effects reduce by 50 percent.
But the researchers say that this doesn't mean you're incapable of having sex.
This is likely because users get confused with the warning of 'if you have an erection lasting more than four hours' referring to a continuous, uninterrupted erection.
10 hours
Even after 10 hours, scientists found men could still get an erection - and at the same rate as they did two hours before taking the drug.
According to the previous study, men can have erections for an average of 23 minutes at 10 hours, and, after 12 hours, the mean duration of erections was reported to be 16 minutes.