Taken at the very first sign of illness will give you the best chance to reduce both the length and severity of any cold or related ailment. We also see many professional athletes cycle onto this supplement when training load is extremely high (e.g preseason) as a precautionary measure for compromised immunity through physical exertion. Zinc and Vitamin C are both water soluble so can be taken on an empty stomach, it’s also best to avoid taking this around any meals or drinks containing dairy.