I catch colds easily. I used to be able to hold them off with lots of vitamin-C. As I've gotten older, vitamin-c hasn't always worked. My sister recommended Umcka to me. I've used it a few times, and each time it's helped stave off a cold. I recently used it with my whole family. We did end up sick, but were better in 1-2 days instead of a week. The only thing I don't like is the cost. You get 20 tablets, but if you're using the recommended dosage, that only lasts one person for one illness.