You've tried everything. Cough drops, decongestants, and some ibuprofen, too. But that sneezing, hacking, and all-around lousy feeling won't go away. Just as you're ready to wave the white flag, you start to wonder: Could an herbal remedy like echinacea save the day?
Researchers are trying to find out. Their answer so far: We're just not sure.
It's a flowering plant that grows in the U.S. and Canada, and it's been used as medicine for centuries. There are nine species. Some of its common names are the purple coneflower or black-eyed Susan. The leaves, stems, flower, and roots are used to make supplements, liquid extracts, and teas.
Does It Work for a Cold?
Studies have had mixed results. Extracts of echinacea do seem to have an effect on the immune system, your body's defense against germs. Research shows it increases the number of white blood cells, which fight infections. A review of more than a dozen studies, published in 2014, found the herbal remedy had a very slight benefit in preventing colds.
Still, sometimes it's hard to compare the results of different studies, because they look at different types and strengths of echinacea, as well as different parts of the plant or root. It's possible that some versions are better than others. Also, it's possible the herbal remedy may be useful against some, but not all, of the more than 200 viruses that cause colds.
Are There Side Effects?
Although the benefits of echinacea for the common cold are uncertain, the risks seem to be low. The most common side effect is upset stomach.
But some people can have allergic reactions. If this happens, you might get: