I'm very skeptical about herbs and supplements. When someone recommends a treatment for something I always look to see if a placebo controlled study has been done.
Umcka cold care is an herbal remedy that looks like it's not a waste of money. If you search the main ingredient Pelargonium sidoides and placebo you find a study titled "This obscure herb works for the common cold"
I started my own test of Umcka on Sunday 11/26.