Many westerners think of plant-based medicine—also known as phytomedicine, from the Greek word for plant—in terms of a shaman tossing herbs onto a smoky fire, while a mom in a hand-stitched tunic sits anxiously nearby holding a sick child in her arms.

True enough: The history of plant-based remedies goes back to Paleolithic times, 60,000 years before there were medical historians to chronicle it. But the best natural medicines have been used through the ages for a reason: They work. If they had killed off practitioners and their patients, who would have passed them on?

The World Health Organization (WHO) estimates that in Africa, about 80 percent of the population relies on phytomedicine or other types of traditional medicine that include animal- and mineral-based medicinal preparations. People of Asia and South America share this approach. In China, botanicals account for up to half of the medicines used. And while you may think of this as a developing-world phenomenon, WHO also points out that 90 percent of Germans have used natural remedies, and 70 percent of Canadians have opened the alternative medicine cabinet.

Meanwhile, less than half of Americans have done so.

And even if you personally don’t think you’ve let a healing plant past your lips, consider this: 25 percent of “modern” pharmaceuticals trace their active ingredients to the natural world. Powerful anti-cancer drugs used to battle Hodgkin lymphoma (Vincristine) and leukemia (Vinblastine) were isolated from the Madagascar periwinkle. Artemisinin, the most effective drug for malaria, was derived from an herbal treatment for fevers. Even such common meds as aspirin (willow tree) and quinine (cinchona tree) were first found in nature, before they were synthesized in the laboratory.

And so to say that phytomedicines can be powerful healers is to state the obvious.

Which isn’t to say that they’re good for whatever ails you. Opioids, derived from the opium poppy, are notorious for their addictive and deadly effects. And a study on herbal remedy health risks published in the European Journal of Clinical Pharmacology detailed a number of side effects (skin eruptions, neurological issues, stomach distress) that came after people took such substances as ginseng, liquorice root, dandelion and fennel to treat ailments. All of which underscores the importance of seeking objective advice before you experiment with a supposedly therapeutic plant.

As the use and appreciation of plant-based medicines has expanded in today’s world, so has scientific research into the use and safety of phytomedicines. Accordingly, many naturopathic physicians, acupuncture therapists, chiropractors and herbalists are digesting the new studies, so they’re now better prepared than ever to counsel patients on the upsides and downsides of phytomedicines.

So while all green medicines aren’t necessarily beneficial, if you seek out the right advice and work with your medical team, you may find that they provide a safe, inexpensive and effective alternative to prescriptions from Big Pharma. Just make sure you consult with a well-qualified shaman before you swallow them whole.