I am typically not allergic to anything. However, these GIANT gummies pack a lot of annatto coloring and while it is natural, I am allergic to it and I broke out in hives and had horrible bout of IBS. As a side note, I can take a lot of vitamin C and not have any abdominal issues. So, it was not the vitamin C. As a side note, I am a little disappointed with the amount of sugar in these dummies. You need to take three of these huge gummies to get the 750mg of vitamin C and that equals 7gms of sugar. This is why I usually avoid all gummies but I thought it would be nice to have these for on-the-go. I broke out in hives and got Diarrhea within 4 hours of taking these so I know it was from these gummies. I had not taken or eaten anything else prior so it was definitely these gummies. I had a reaction before this last one and thought it was the dye in a ibuprofen liquigel tab. Too bad I did not identify this first time I took these gummies. It takes at least 24 hours to get these darn hives on my face to go away