Herbal food supplements

Since 1997 in Belgium, a Royal Decree has defined a list of so-called non-toxic plants and a list of plants recognized as potentially dangerous. Since this publication, an industrialist can manufacture and sell a  dietary supplement based on plants appearing on the non-toxic list. They are not even required to prove that the plant used in the product actually has the virtues they claim, or that the concentration of the plant's active ingredient in the tablets is sufficient to be effective in any way. Plants recognized as toxic are obviously prohibited, but the list published in 1997 is far from exhaustive.

On the other hand, for herbal medicines, it's much more difficult to get them onto the market. The advantage is that their chemico-pharmaceutical quality is guaranteed by constant monitoring, and that their claimed therapeutic virtues must have been demonstrated: efficacy must have been proven, which constitutes a guarantee. 

It's not uncommon for a plant to be found in both products (medicine and dietary supplements). In this case, their quality is not comparable. In fact, dietary supplements are sometimes (often) significantly under-dosed: the absence of toxicity is undoubtedly guaranteed, but so is the absence of efficacy! Prices, on the other hand, are grossly overdosed ! Take Ginkgo biloba, for example! The majority of scientific studies that have led to the marketing of drugs use a standardized extract approximately 50 times more concentrated than leaf powder. However, dietary supplements are marketed which only contain forms that are much less concentrated, or even diluted in relation to the original plant. Paradoxically, the companies marketing some of these dietary supplements claim that they have an effect on memory and that they "stimulate intelligence", whereas scientists still don't even dare to claim that the concentrated extract (used in medicines) has a real effect on memory in healthy subjects. Indeed, the effect on memory has only been proven in elderly subjects with cognitive disorders (including Alzheimer's disease).