The supplement Ginkgo biloba has failed to ward off Alzheimer’s disease or other forms of dementia any better than a placebo in a long-term trial, researchers report in the Nov. 19 Journal of the American Medical Association (JAMA). . . . U.S. sales of ginkgo averaged $170 million from 2000 to 2004.
The herb joins homeopathy, over the counter cough and cold medicine for children under six, and a number of common over the counter herbal and conventional medicines used for long periods of time that have been established to be ineffective medical treatments for the conditions that they are reputed to treat.
There are effective over the counter drugs (asprin for minor pain, fever and cardiovascular health, naproxin for prolonged minor pain and fever), herbs (e.g. Russian herb Rhodiola rosea and marijuana), foods (honey for children's coughs) and drinks (alcohol for cardiovascual disease, certain teas, and alcohol in moderation all have well established medical benefits for example). But, many don't work.
The verdict is still out on other herbs like Echinacea (taken to reduce the severity of a cold).
In the case of St. John's Wort, there is some evidence that it may be helpful in alleviating minor depression, but it is ineffective at relieving major depression.