UCL School of Pharmacy


BBC Two ‘Trust Me I’m A Doctor’ highlights quality problems of unregulated food supplements

6 August 2015

On 15 July 2015 work at the UCL School of Pharmacy was featured in the BBC Two television series Trust Me, I’m a Doctor. The research group tested more than 70 commonly used food supplements. While herbal medical products registered under the Traditional Herbal Registration (THR) scheme all contained the constituents as claimed, but many of the food supplements were found not to contain any relevant bioactive natural products. In other words, they do not contain what they claim to contain.

Gingko leaf

A team at the UCL School of Pharmacy, led by Michael Heinrich, Professor of Pharmacognosy, found that many food supplements do not contain what is claimed on the label. More than a quarter of the 30 ‘Ginkgo biloba’ products (all food supplements) tested contained  little or no ginkgo extract. In the case of milk thistle (silybum marianum), more than a third of the food supplements contained no detectable milk thistle.

All of the evening primrose (oenothera biennis) food supplements tested seem to contain what the packet claimed. Clearly such research has limitations since the team did not test for other contaminants like heavy metals, pesticides or herbicides, but it highlights the need for more stringent quality control regulation and a better monitoring of such products. The research has also led to further investigations by the Food Standards Agency (FSA).

The project is part of a larger project investigating the value chains of herbal medicines and food supplements, the quality of such products and the impact of different production systems on the livelihoods of the producers (e.g. in India, see Booker et al 2014). Suppliers of such products need to understand the value chains leading to the final products and need to ascertain the quality of their material along the entire chain. 

Overall the research calls for better regulation if applicable as THR products but also for a more rigorous enforcement of basic quality standards of herbal food supplements by the Food Standards Agency.

Further information:

The Traditional Herbal Medicinal Products Directive was implemented in 2004 and stipulates that only registered herbal products may be sold as OTC medicines. Their use is based on a tradition of use only. Traditional herbal registration (THR) medicines have known quality and safety, and documented traditional use. Only limited therapeutic claims can be made, and their use is only for minor self-limiting conditions. They normally are administered topically or orally.
Information of what (often very limited) evidence is available for herbal medicines can be found at:

Publication on Phytopharmacy: Edwards, S., I. da Costa-Rocha, E.M. Williamson and M. Heinrich* (2015) Phytopharmacy – an evidence-based guide to herbal medicines. Wiley, Chichester.

BBC 2: Trust Me, I'm A Doctor - 15th July 2015

Contact: Professor Michael Heinrich


The image above illustrates the HPTLC chemical traces of a sample of the ginkgo products that were tested. The first band on the left is the reference standard – so this is the pattern that is looked for. It is very easy to see which samples contain little to no ginkgo simply by comparing them to the reference.