Writing in BMC Medicine, the researchers, led by David K Raynor from the University of Leeds, found one third of consumers had no knowledge about possible safety issues with herbal products like St John’s wort and ginseng due to interactions with drugs and other factors.
These included St John’s wort reducing the effectiveness of contraceptive pills or the effectiveness of blood clotting pharmaceuticals; Asian ginseng not being suitable for diabetics or Echinacea causing allergic reactions.
“Consumers need reliable and comprehensive information when buying herbal remedies – information which tells them whether the remedy is suitable for them,” said Professor Raynor.
“People should look out for the ‘[THMPD] logo’ when buying these products. Furthermore pharmacists and doctors need to be made aware what herbal remedies people are taking so that their patients receive the best possible care.”
The researchers found in a survey of St John’s wort, Asian ginseng, echinacea, garlic and ginkgo, that only 51 of 68 products contained key safety information.
But the Traditional Herbal Medicinal Products Directive (THMPD) was improving product information, they observed. Previously insufficient products included, “4 of 12 St John’s wort products, 12 of 12 ginkgo products, 6 of 7Asian ginseng products, 20 of 21 garlic products and 9 of 13 echinacea products.“
THMPD registered products, on the other hand, “contained at least 85% of the safety messages.”
They noted 93% of the products tested did not have THMPD registrations, but there is a sell-through period permitted for such products.
The products were bought in two well known health food stores, three large chain pharmacies, and three pharmacies at supermarkets.
In regard to potential contraindications with pharmaceutical treatments, they observed: “…many people believe that herbal products are safebecause they are natural, confirming previous findings, and that patients often refrainfrom telling their physicians if they are using an herbal product. Equally important is that fewdoctors ask patients about their use of CAM, including herbal products.”
They concluded: “It is clear that consumers are entitled to better information with the CAM that they buy, so that they are aware of any safety issues and to enable them to make informed decisions.”
Published online ahead of print
‘Buyer beware? Does the information provided with herbal products available over the counter enable safe use?’
Authors: David K Raynor, Rebecca Dickinson, Peter Knapp, Andrew F Long and Donald Nicolson