Viagra should be taken orally 30 minutes to four hours before sexual activity but is most effective if taken one hour beforehand. Also check out Taking Viagra with marijuana https://www.edrugstore.com/blog/erectile-dysfunction/viagra/can-i-take-viagra-with-cannabis/?amp=1

After you’ve taken Viagra for the first time and have a better understanding of how it works, it will be easier to use on a more regular basis. Some people may need to take it one hour before sexual activity, whereas others may find that it takes closer to two to three hours to start working for them.