The Benefits and Side Effects of Ginseng

Ginseng root is a popular herbal medicine. Like the word panacea, ginseng’s Latin name, Panax, is derived from the Greek for “cure-all.” It can extend the lives of fruit flies and microscopic worms, but not mice. What about people?

Well, there have been more than 100 clinical trials using various ginseng formulations, but the results have been underwhelming. A meta-analysis of randomized, double-blind, placebo-controlled trials found ginseng did not appear to significantly affect the duration of illness but did appear to reduce the risk of developing acute upper respiratory infections in the first place. Digging deeper, however, the preventive benefit appears limited to Asian ginseng, which cut infection risk in half compared to placebo, as opposed to American ginseng that only reduced risk 16 percent, which did not reach statistical significance.

Asian ginseng can then be further divided up by processing method. “White” ginseng is Asian ginseng root that’s simply been washed and dried, whereas “red” ginseng is the same root but undergoes an additional step of steaming before drying. Red ginseng is often used for male erectile dysfunction. While it doesn’t appear to help with female sexual dysfunction, a meta-analysis of a half-dozen randomized controlled trials found that 4 to 12 weeks of 1.8 to 3 grams a day of Korean red ginseng can improve erectile disfunction compared to placebo. Fifty-eight percent of men experienced an improvement in sexual function compared to 20 percent of men in the placebo group. This may be due to an improvement in artery function demonstrated within three hours of consumption.

Of course, this is assuming there’s actually ginseng in your “ginseng.” Ginseng is a multibillion-dollar industry, and, as such, suffers from intentional contamination with cheaper filler substitutes, some of which may not be benign. If your quote-unquote “ginseng” supplement turns out to just be powdered soybeans, then you’ve just wasted your money. But, for example, if it’s been spiked with illicit horse painkiller, it’s worse than a waste. A study of the more than 500 ginseng products sold in a dozen countries across six continents found that 24 percent were adulterated. This is consistent with so-called “immune boosting” supplements in general. A 2022 analysis found most such products failed to match what was on their labels.

Maybe it’s good there’s no ginseng in your ginseng? From an oxidative stress standpoint, American, Chinese, and Korean ginseng all have been shown to acutely protect against free radical-induced DNA damage within hours of consumption, but one longer-term trial raised red flags. Although four weeks of Korean ginseng reduced levels of oxidative stress, four months of American ginseng (about a quarter teaspoon a day of whole root powder) caused an uptick in DNA damage. Until it can be shown that chronic intake of other ginsengs isn’t also DNA-damaging, I’d recommend steering clear.

Approximately 10 percent of users suffer from what’s been termed ginseng abuse syndrome, which manifests as high blood pressure, nervousness, sleeplessness, skin eruptions, and morning diarrhea. Of course, it may not actually be from ginseng itself but rather adulterants in some supposed ginseng product.

What if you randomize people to ginseng that’s been officially authenticated? In a multicenter, double-blind, randomized, placebo-controlled safety trial, a thousand people were randomized to two grams a day of red ginseng or placebo for six months. In the ginseng group, 345 adverse events were recorded. But the placebo group had 389 adverse events. Each of the top five quote-unquote “side effects” were documented more often in the placebo group.

Outside of a clinical trial, though, it’s hard to know what you’re going to get. Aside from the abuse syndrome symptoms, there have been case reports of manic psychosis, estrogenic effects, and increased surgical bleeding. And so, some recommend ginseng should be avoided in those expected to undergo surgery, those with a predisposition to mania, estrogen-dependent disease, hypertension, or hyperthyroidism.