The 34-year-old, who plays his club rugby for Edinburgh, has admitted that he no longer felt like he could give 100% to the Scotland cause.
"To play international rugby you have to be absolutely committed. You have to make sacrifices and do all the extra stuff in training and preparation to be right," he said in a statement.
"I've always tried to do that throughout my career and playing for Scotland has meant the world to me.
"But the minute there is the possibility of it feeling like a chore, that's the slippery slope for me and I would never want to do anything that would either devalue the Scotland jersey or anything that I've achieved."
The prop represented his country on 65 occasions.