Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Source Naturals L-Tryptophan, 500 mg.

My experience with Source Naturals L-Tryptophan 500 mg. capsules has been excellent. Follow the instructions on the label and you will be on your way to feeling better. I recommended it to a friend and he also started feeling better, he had used prescription antidepresants before but he wasn't getting good results, plus they had side effects he didn't want. Moreover, they were more expensive.I personally stay away from refined sugars since I'm sensitive to them and get depressed easily, but for those instances when I feel a little bit down anyway I reach for my bottle of Tryptophan and use it for a couple of days and that's it, I feel upbeat and better again.