Ginseng — does it work? How?

Originally Published: December 19, 2008
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Dear Alice,

I have been taking Ginseng (Korean 75mg) on and off regularly for a few years now and have noticed that it appears to reduce fatigue, enhance my sex drive and boost my immunity (fewer colds). I am a science teacher and a few of my colleagues argue that there is no scientific evidence for the alleged benefits of this supplement.

Are they right? Is it just the placebo effect? If it does work, what is its magic ingredient?


Dear Reader,

That's a tough argument to referee. On one hand, your colleagues are right; there are no scientifically conclusive studies or tests that show exactly what ginseng does or how. On the other hand, several small studies illustrate ginseng's powerful effects on the body, many of them along the lines of just what you said — energy, immunity, and sexual functioning. The fact that ginseng has been used world-wide for thousands of years, and that anecdotal evidence of its power is abundant (including your own experience), chances are that the energy-enhancing, libido-boosting, immunity-supporting capabilities of this herb are more than just placebo effect and positive thinking.

Ginseng is most commonly credited with:

  • aphrodisiac properties — improving libido and sexual performance (shown in laboratory rats), sometimes a treatment for erectile dysfunction
  • improving mental and physical performance — some use it to increase concentration and information retention, athletes use it to enhance performance
  • boosting the immune system — it has been shown to increase white blood cell counts in humans, also believed to help the ill or weak regain strength and vigor
  • anti-depressive effects
  • sedative effects
  • decreasing appetite
  • lowering blood glucose
  • relieving symptoms related to menopause

Several studies have shown that ginseng can improve thinking and learning when taken in daily doses of 200 to 400 milligrams of standardized extract for 12 weeks. Studies also report that ginseng may stimulate activity of immune cells in the body (T-lymphocytes and neutrophils), and improve the effectiveness of antibiotics and flu vaccines. Use of ginseng has also improved erectile function, sexual desire, and intercourse satisfaction in studies of patients with erectile dysfunction.

How does one herb achieve all this? The "magic ingredients" are most likely the active chemical compounds, called ginsenosides or panaxosides, contained mostly in the root, but also in the leaves and seeds of the plant. Over 20 different ginsenosides have been identified. Perceptive readers may have noticed that some of the uses of ginseng seem to contradict each other, such as acting as both a sedative and a stimulant. This remarkable capability to affect the body in different ways is due to the fact that while the various panaxosides are similar in structure, they can exert opposing effects. For example, the panaxoside Rb-1 acts as a central nervous system (CNS) depressant, having a stress-reducing effect with anticonvulsant, analgesic, and antipsychotic properties. But panaxoside Rg-1 is stimulating to the CNS, serving to ward off fatigue, increase performance, and possibly turn you on.

It's recommended that you follow the dosages prescribed on the box, or by an herbalist. A typical dosage is about 0.5 to 2 grams dry root daily, or 200 to 600 ml liquid extract daily. Be careful to avoid taking ginseng in larger doses than recommended, or simultaneously with other stimulants such as tea, coffee, or MAO inhibitors (anti-depressants). Diabetics should also be cognizant of ginseng's potential to lower blood sugar, and take that into consideration when administering insulin or eating. As with many herbs, pregnant or breast-feeding women should probably not take ginseng, as effects are unknown.

Some side effects are possible, and are most likely to occur with overuse, overdose, or allergies. Typical side effects include headaches, insomnia, gastrointestinal upset like diarrhea or vomiting, breast tenderness, menstrual irregularities, high blood pressure, and skin eruptions. If you experience any of these side effects while taking the supplement, you may want to lower your dose, or stop taking it altogether to see if the symptoms cease. Also, inform your health care provider about ginseng or any herbal supplement you are taking, especially if you are taking prescription medication. It's important that people who use ginseng or any herb understand that natural medicines are not regulated by the FDA, and that there may be both long and short-term side effects not yet discovered.

In terms of your continued ginseng use or what to tell your colleagues, it seems that ginseng's effects on your body are consistent with small studies and anecdotal evidence, and likely more than the placebo effect. But to date, only a handful of large clinical trials on ginseng have been conducted, so undisputable proof is something only more testing can bring.

In the meantime, enjoy the benefits you are receiving, and watch for any signs that your body's had enough.