Herbal supplements 'lack safety info'

“Herbal medicines lack safety warnings,” The Independent has today reported. The newspaper says that this is despite the April 2011 introduction of new EU rules stipulating that they should carry warnings. 

This news is based on a study that examined five commonly used herbal supplements to determine whether they included safety and usage information prior to the new legislation. Researchers found that the majority of products did not supply important information on their use, despite some of them having the potential to interfere with certain prescription medicines.

While the research provides a snapshot of the situation prior to the new EU rules, which were intended to simplify the licensing of herbal medicines, it is still relevant now. Several herbal products are classed as foods and therefore fall outside of the regulations, while retailers can still sell remaining stocks of regulated products without updating their packaging.

There is sometimes a misconception that herbal products are safe because they are “natural”, but in fact they can interact with prescribed medications, cause side effects or be unsafe for people with certain illnesses. Individuals should read any provided safety information and discuss the use of herbal medicines with their GP or pharmacist before using a new product. In particular, they should consult authoritative bodies such as the Medicines and Healthcare Regulatory Agency, which provides detailed information on the regulation of herbal products.

Where did the story come from?

The study was carried out by researchers from the University of Leeds, the University of York and the University of Dundee. It was funded by the University of Leeds.

The study was published in the peer-reviewed medical journal BioMed Central Medicine.

The media generally reported the news accurately.

What kind of research was this?

This was a cross-sectional survey that aimed to evaluate how many common herbal health products provided sufficient safety information on their packaging. Researchers selected five types of products that met one or more of the following criteria:

  • There was evidence of an interaction between the product and a prescribed medication.
  • The product had previously been subject to type of study called a risk-benefit profile, which is designed to evaluate the safety and effectiveness of a product.
  • The product had been readily available, such as being sold in local shops, pharmacies and supermarkets.

On this basis they decided to examine products containing:

  • St John’s wort
  • Asian ginseng
  • echinacea
  • garlic
  • ginkgo

The analysis was performed before the implementation of the Traditional Herbal Medicines Products Directive (THMPD) in April 2011 – a piece of EU legislation that changed the way certain herbal products can be labelled and marketed. However, many herbal products are still not subject to this legislation as they are classed as food products, and others can still be sold with their old packaging if shops had stocked them prior to the legislation coming into force.

What did the research involve?

The researchers purchased a total of 68 individual marketed preparations and products from pharmacies, health food shops and supermarkets. They only selected products containing the single ingredients: in other words, not products combining different herbal ingredients. The researchers examined the written safety information provided for each product, and evaluated whether it included complete and correct information about precautions, interactions with conventional medicines and side effects. Each product’s safety information was compared to data provided by the US National Centre for Complementary and Alternative Medicines.

The researchers marked each product’s safety information according to 16 separate criterion, judging information on them as either “present and accurate” or “inaccurate or absent”.

What were the basic results?

The majority of the products (63 of the 68 examined) were unlicensed, and 48 of these unlicensed products were marketed as food supplements. The remaining five products were either licensed or registered as Traditional Herbal Medicinal Products; a class of product required to meet specific standards of safety and quality and to be accompanied by information on appropriate usage.

The researchers found that 75% of the products contained no safety information at all. St John’s wort has previously been shown to interact with contraception pills and warfarin, yet two thirds of the St John’s wort products did not provide information on possible drug interactions.

Three products provided information on most or all of the key categories assessed. This included the two products registered as a Traditional Herbal Medicinal Product, which provided information in 14 of the 16 categories.

How did the researchers interpret the results?

The researchers concluded that readily available herbal medicines still fail to provide safety information. They say that regulations should be strengthened further, as there was evidence that tightened regulations improved the provision of information on packaging. For instance, the single St John’s wort product registered as a Traditional Herbal Medicinal Product contained 85% of the expected safety information.


This study examined the safety information currently provided with numerous different brands of five of the most common herbal medicines.

The study was carried out before the EU ruling that increased the regulations surrounding disclosure of safety information for some herbal medicines. However, the ruling allows currently available stock to be sold with its old packaging until its expiry date. Therefore products that do not meet the new regulations are likely to remain on the shelves for some time. Some other herbal products are also classed as foods, and therefore fall outside these new regulations.

The researchers say that few products meet the stricter licensing requirements that apply to conventional medicines, as reproducible evidence of the product’s effectiveness often does not meet licensing standards. Therefore many are currently sold as unlicensed products.

The researchers recommend that individuals are made aware that there may be safety concerns with herbal products that are not disclosed, and that when possible individuals should purchase products granted a THR logo by the Medicines and Healthcare Regulatory Agency. It is also important that consumers read any safety information included with the products they are planning to take, whether conventional or herbal medicines.

Herbal supplements can interact with medical prescriptions, have side effects and be unsafe for people with certain illnesses. In order to make informed decisions regarding your health, it is best to discuss all drugs and products you are using with your GP or pharmacist, including herbal products.

The study provides a useful snapshot of the status of currently available safety information at a time when policy regarding the provision of such information was changing. However, it is still unclear what the impact of the newly effective EU policy will be. This will probably be difficult to assess until all remaining old stock has been sold or has expired.

NHS Attribution