Many herbal supplements, including for obesity and erectile dysfunction, found to contain hidden pharmaceutical ingredients that could endanger people’s health.

A research team, comprised from Queen’s University Belfast, Kingston University in London and the life sciences testing company LGC, examined the detection of illegal ingredients in the supplements.

The research found that over-the-counter supplements – commonly advertised to treat obesity and erectile dysfunction problems – are labelled as fully herbal but often include potentially dangerous pharmaceutical ingredients, which are not listed on the label.

It concluded that not only do such supplements often make unverified claims as to their benefits but some have illegal ingredients which could pose a threat – potentially causing low blood pressure or an increased risk of heart attacks.

Professor Burns from Queen’s University, who is working to advance knowledge in this area, explained: “Our review looked at research from right across the globe and questioned the purity of herbal food supplements. We have found that these supplements are often not what customers think they are – they are being deceived into thinking they are getting health benefits from a natural product when actually they are taking a hidden drug.”

“These products are unlicensed medicines and many people are consuming large quantities without knowing the interactions with other supplements or medicines they may be taking. This is very dangerous and there can be severe side effects.”

The survey also raises serious safety questions for slimming supplements containing Sibutramine. Sibutramine was licensed as the medicine Reductil until 2010, when it was withdrawn across Europe and the US due to an increased risk of heart attacks and strokes associated with the use of the drug.

Tadalfil and sulfoaildenafil were among the most frequently undeclared ingredients found in products for erectile dysfunction. When taken with other medicines containing nitrates, Tadalfil and sulfoaildenafil can lower blood pressure drastically and cause serious health problems.

Professor Burns noted: “This is a real issue as people suffering from conditions like diabetes, hyperlipidemia and hypertension are frequently prescribed nitrate containing medicines. If they are also taking a herbal supplement to treat erectile dysfunction, they could become very ill.

“People who take these products will not be aware they have taken these substances and so when they visit their doctor they may not declare this and it can be difficult to determine what is causing the side effects. It is a very dangerous situation.”