While the previous post was about seeing a traditional herbalist (who prescribe their own herbal mixtures, tailor-made for each individual patient), this post provides essential information for those consumers who are tempted to take a commercially available herbal remedy available in pharmacies, health food shops, over the Internet etc. These remedies are usually bought by consumers and then be self-administered, or (less frequently) they might be prescribed/recommended/sold by a clinician such as a doctor, naturopath, chiropractor etc. Typically, they contain just one (or relatively few) herbal extracts and are used under similar assumptions as conventional medicines: one (hopefully well-tested) remedy is employed for treating a defined condition, diagnosed according to validated and generally accepted criteria (for instance, St John’s Wort for depression or Devil’s claw for back pain). This approach is sometimes referred to as ‘rational phytotherapy’ – it is certainly more rational than the traditional herbalism referred to in my previous post. The manufacture, promotion and sale of commercial herbal remedies (in many countries marketed as ‘dietary supplements’) has grown into a multi-billion dollar industry.
Here are a few essentials you ought to know before you decide to take such an herbal remedy:
- Many people claim that herbal medicine is effective because many of our modern drugs are based on plants. The latter part of this claim is true, of course, but this does not necessarily mean that herbal remedies are effective. The drugs derived from plants contain one single, well-defined, extensively researched molecule (by definition, this makes them conventional drugs and not herbal remedies), while herbal remedies are based on entire (parts of) plants; thus they contain many pharmacologically active molecules. This often means that it is difficult or impossible to tell what dose of which ingredient is being administered and what pharmacological actions can be expected.
- Even though national regulations differ greatly, herbal remedies generally do not have to be supported by evidence for efficacy in order to be legally available. This means that a given remedy might or might not have been tested in clinical trials to determine whether it works for the condition advertised. In fact, only very few (less than 30, I estimate) herbal remedies are supported by sound evidence for efficacy; thousands do not meet this criterion.
- The extremely wide-spread notion that herbal remedies are by definition natural and therefore safe is nothing but a promotional myth. Plants contain many chemicals which can have pharmacological activity. This means they might be therapeutic, but it also means that they might be toxic (traditionally the most powerful poisons originated from the plant kingdom). If anyone uses the ‘natural = safe fallacy’ remind him/her of hemlock, poison ivy etc.
- In addition to potential toxicity of an herbal ingredient, there are other important safety issues to be considered. Most importantly, herbal remedies can interact with prescribed medicines. For instance, St John’s Wort (one of the best-studied herbal remedies in this respect) powerfully interacts with about 50% of all prescription drugs – in fact, it lowers their level in the blood which means that a patient on anti-coagulants would lose her anti-coagulant protection and might suffer from a (potentially fatal) blood clot.
- In many countries, including the US, the regulation of herbal remedies is so lax, that there is no guarantee that an herbal remedy which is being legally sold is safe. The regulators are only allowed to intervene once there are reports of adverse effects. This means that the burden of proof of safety is effectively reversed which obviously exposes consumers to incalculable risks.
- The quality of the herbal product is equally poorly regulated in most countries. A plethora of investigations in the US, for instance, has shown that the dose of the herbal ingredient printed on the label of a commercial product can range virtually from 0 – 100%. Similarly there is little safe-guard that the ingredients listed on the label correspond to the ones in the preparation. This means that it is worth purchasing not just well-researched herbal remedies but also those marketed by high quality manufacturers via respectable outlets.
- Any regulation of herbal remedies, even the European one that is often praised as protecting consumers adequately, is null and void once consumers go on the Internet and purchase their herbal remedies from one of the many dubious sources found there in truly alarming profusion. Bogus claims, inferior quality and even outright dangerous products abound, and it is often impossible to tell the acceptable from the fraudulent product.