how much L-Glutamine per day?

I use a level desert spoon, 3 times a day, though this article suggests that you can go as high as a tablespoon of the stuff, 3 times a day (~50grams per day).

Listen to Your Gut recommends 1-6 teaspoons per day. It's best to break it up into several doses throughout the day. However, you may want to proceed cautiously because, for some folks, this stuff works so well, too large a dose could actually constipate you. The book recommends starting with a quarter teaspoon a day. If that causes no problems, go up to a half teaspoon and continue to increase, keeping an eye on your symptoms.