Jeremy Renner accidentally took a Viagra pill instead of a sleeping aid during an 11-hour flight from Los Angeles to London.

The actor digested what he thought was Ambien only to realize minutes later he had mixed up his "A" with a "V." Instead of sleeping he spent the entire flight wide awake with a painful erection.

He explained on "Jimmy Kimmel Live," "I had to get off the plane to go to work so I had to sleep on the plane...Somebody gave me some pills...so great.
 
"I took a little sleeping pill...and I realized nothing's happening but something else is happening, and I realized pretty quickly that that 'A' was a little 'V' on the pill. Not only did I not sleep on the entire flight, I was camping...There was no walking. If I had to go to the restroom, it was so embarrassing.
 
"I had Dennis Hopper, God rest his soul, laying next to me and his daughter was there playing with this little glass menagerie on the ledge...I'm like playing with her and I'm like, 'Hold on a second, man. I'm gonna go to jail, I'm gonna get arrested. This does not look good.'"

Renner stars in the upcoming film "The Bourne Legacy." Check him out on "Jimmy Kimmel" below: