I have been taking TF for a little over a year. I've read a lot of posts from different folks who are taking or have taken TF and gotten a reaction. I know what benefits I've received from taking it and I was concerned about the reactions I've heard others have had so I just wanted to post something which may be informative to those folks. I wondered about the manufacturer from whom they are buying. I was first introduced to TF through a doctor friend (a gyn-oncologist) whom I have known for 30 years. He would never recommend something which he himself has not researched or taken himself. The company who manufactures my TF is 4-Life. Although there are plenty of other companies out there manufacturing and selling it with the name TF, I am skeptical as to whether or not it's the "real deal". My mom ran out of hers and decided to buy from one of those mail order vitamin catalogs because it cost about 1/3 of the price as the one from 4-Life. As it turned out, she had some kind of reaction and didn't take any more. Then when she started to get a relapse of the flu and bronchial infection she had had, she started taking the TF from 4-Life again and warded off further illness. Recently, I caught a terrible cold and upper respiratory infection. I immediately started taking my TF (in triple of normal dose- I had not been taking it daily anymore). The symptoms began to dissipate and I never had to go to the doctor. My husband caught my cold a couple of days after me and did not take any TF. About 3 days into his cold, he also went into a bad upper respiratory infection and ended up at the doctor for antibiotics. The whole point of this is that I don't think all TF brands are alike and I'm going to go with one that I know my trusted doctor friend has put a stamp of approval on.