After taking Viagra, the medication quickly enters your system and starts working after about an hour, but you can take it anywhere from 30 minutes to 4 hours before sexual activity.
This means that you’ll want to take it about an hour before sexual activity, but you’ve got a wider window of time for when you can still get a benefit. However, as mentioned above, it only works if you’re aroused.
You may be wondering if there are ways to help the medication work even faster, like chewing or crushing the tablet and dissolving it under your tongue. However, it isn’t made to work that way and should be swallowed whole.