Started giving this to my husband when he started radiation therapy for Lung cancer. Radiation to the chest area can cause severe esophagitis, and my research showed L-glutamine to be helpful in reducing the severity. My husband was symptom free for 5 of the 6 weeks of radation, only starting with a sore throat after week 5. His radiologist was amazed, said most patients start showing symptoms by week two! I give him 2 tsp three times per day. UPDATE: Husband finished radiation about a month ago. He decided to stop taking the L-glutamine 3-4 days ago without telling me. Today the esophagitis symptoms started returning, and he has been "regular" for the most part, but now complaining of constipation so I believe it was helping with that as well as residual esophagitis for sure. Has never had problems with neuropathy, so he STAYS on this stuff for a few more months, at least