Does Herbal Medicine Work?

It's all natural! No side effects! It cures everything! (Did I mention it was all natural?) Ask Science looks at the science (and science fiction) of herbal medicine and homeopathic remedies.

Lee Falin, PhD
4-minute read
Episode #7

Does Herbal Medicine Work?

What do herbal medicine, probiotics, chiropractic care, meditation, magnet therapy, and homeopathy have in common? They are all on the National Institute of Health’s list of “Complementary and Alternative Medicines” or CAM for short.

Proponents of these practices claim that they are just as effective (or even more effective) than conventional medicine. Some people even go as far as to claim that doctors, nurses, and other higher-ups in the conventional medicine ranks are involved in a conspiracy to suppress knowledge of these things.

So how much if this is true? Do herbal medicines work? Is it true that herbal medicines have “no side-effects” because they’re all natural? Is there a shadowy FDA conspiracy to suppress the truth about medicine? Who are these FDA people anyway and can we trust them? Let’s use science to find out.

Flower Power

I wish I had time to look at every alternative medicine technique today, because there really are some interesting ones. We’ll start small and look at one of the most popular herbal supplements on the market today, Echinacea.

According to the product label on a popular brand of Echinacea supplements, “Echinacea helps general well–being during the cold and flu season.” Another bottle claims “Echinacea is one of the world’s leading herbs for immune system support.” 

Echinacea is actually the name of a genus of flowering plants in the daisy family which containing multiple species. The most common species used in herbal medicine is Echinacea purpurea, or Purple coneflower.

See also: For more about taxonomic classification systems, see What Is Interspecies Breeding?


As with many other epidemiological studies, current research is a bit divided about the efficacy of Echinacea. A 2008 study found that Echinacea was effective at inhibiting the activity of Rhinovirus (the main virus that causes the common cold). Another study in 2009 found that Echinacea extract was more effective than Tamiflu at inhibiting the H1N1 and H5N1 virus replication in cell cultures. (Though it should be noted that a company that manufactures Echinacea extract funded the 2009 study.)  

Well that’s all great for cell cultures, but what about real people? The most well-known review on the effectiveness of Echinacea analyzed the results of 14 separate studies and found evidence that Echinacea can help prevent you from getting colds and can help shorten the duration of a cold if you do get one. Critics of this review say that the combined studies were too different in scope to be combined in a way that allows you to draw meaningful conclusions.

Still, the odds seem in your favor. Shouldn’t we all rush out and buy some Echinacea supplements? Like most difficult questions in science, the answer is a definite…maybe.


Please note that archive episodes of this podcast may include references to Ask Science. Rights of Albert Einstein are used with permission of The Hebrew University of Jerusalem. Represented exclusively by Greenlight.

About the Author

Lee Falin, PhD

Dr. Lee Falin earned a B.S. in Computer Science from the University of Illinois, then went on to obtain a Ph.D. in Genetics, Bioinformatics, and Computational Biology from Virginia Tech.