My sister was sick for 2 years with Mono that turned into Chronic Fatigue. We tried many things and nothing seemed to work. Finally a Naturopath told us that her immune system was over active which he said happens a lot in cases like these. He told us to take Marshmallow Root & Astragalus Root. We found a combination from Dr. Christopher's but that is just the one we went with, I'm sure there are others out there. She takes it religiously and has gotten back to her old self. I don't know how long she will have to take it, she's been on it for about 5 months and did try going down once and was able to, however when she tried going off of it she was getting the old symptoms back. It was such a blessing that someone recommended this to us. God Bless!!!