My vits do this, as well. I just noticed within the last month or so. They also seem to make me a little more tired and delay my period. LOL, I'm like: "I'm being celibate, so I know I'm not pregnant!!!" I'm pretty sure I'm not allergic to any of them. I wonder which one is the culprit, or if it's a combo. I'm taking kelp, a multi, b-complex, and c. Just re-reading the post-- maybe it's the b-complex? It's one of my newest vits and I see you're taking that, Kurlee.