Yes, they do. However, understand that these natural cold and flu remedies are not really “curing” anything. If you see a product claiming anything along those lines, that is a red flag. But what many of these products do – and homeopathic remedies do not fall into this category as they’re completely worthless – is simply boost your immune system with vitamins and sometimes additional minerals or phytonutrients. In fact, many of them are not unlike a potent multivitamin. The studies on “curing” colds with natural remedies are inconclusive, but studies have shown time and again that vitamins like C, the B-complex, and many other supplemental nutrients absolutely have immuno-strengthening properties. That’s why I recommend always taking steps to boost your immune system on a daily basis, whether you’re sick or not. Don’t wait until you feel the first itch of a sniffly nose to begin boosting your immune system. Prevent what you can before you even get it.