Pronounced "o-sil-o-cox-see-num," this world-famous formula from Boiron is "the first thing to take at the first sign of flu." A non-drowsy homeopathic medicine, it's safe and natural, with no drug interactions or other risks associated with over-the-counter synthetic remedies. Oscillococcinum works best when taken at the first signs, so make sure you have some on hand the next time the flu sneaks up on you.