50%+ weight loss botanicals laced with pharma: French research

By Annie Harrison-Dunn

- Last updated on GMT

Among the 164 samples analyzed, only 44% were either truly 'natural' or in line with their labels. © iStock.com
Among the 164 samples analyzed, only 44% were either truly 'natural' or in line with their labels. © iStock.com

Related tags Weight loss Food supplements Pharmacology Medicine

Over half of so-called 100% natural botanical slimming supplements are adulterated with unlabelled pharmaceuticals, according to French tests of 164 products.

The researchers from the University of Toulouse said the results highlighted the need for more effective quality control of weight loss food supplements.

They found 56% of the 164 samples tested were adulterated with active pharmaceutical ingredients despite claiming to be ‘100% natural’.  

Sibutramine alone was found in 26% (43) of the samples, while 6% (nine) contained phenolphthalein alone and 14% (23) a combination of the two.

Sildenafil, fluoxetine, orlistat and lorcaserine were also detected.

Pharmaceutical ingredients are not permitted in food supplements under European law. In some cases - such as the appetite suppressant sibutramine and laxative phenolphthalein - the substances were banned in pharma products too due to associated health problems.

pie chart botanical reslults

The few drugs approved for weight loss purposes are available on prescription only, meaning consumers looked to self-treat weight and obesity problems with slimming food supplements freely available in pharmacies, health food stores, the researchers said. 

They said such supplements were “aggressively marketed with extreme claims such as quick and easy weight loss, totally safe, all natural or 100% natural”. ​ 

The tested products boasted botanical ingredients including coffee, acai berry, hoodia and extracts of papaya and pineapple. 

“However, most often these claims are exaggerated or even dishonest as some unscrupulous manufacturers do not hesitate to fraudulently add synthetic active pharmaceutical ingredients (API) in order to improve the efficiency of their preparations,” ​they wrote in the Journal of Pharmaceutical and Biomedical Analysis.

The samples were bought largely online, while seven were purchased in French specialist health shops and 12 in pharmacies in Lebanon.

'Rapid and simple' method

The study used H NMR as a detection method. They said the results showed this was a “rapid and simple”​ method for spotting adulteration of supplements. 

“In this study, we demonstrated the power of high-field H NMR as a screening method for the detection, identification and quantitation of adulterants in slimming food supplements.

“Among the 164 samples analysed, only 44% were either truly natural or with a composition conform to the label.”

Levels of these substances varied across capsules within the same blister pack, which the researchers said highlighted poor manufacturing practices.

Robert Verkerk, executive and scientific director of the Alliance for Natural Health International (ANHInternational), said this was an issue of low quality manufacturing below both pharma and food legal standards. 

“Adulteration with pharmaceutical ingredients is a very real problem for products supplied through the Internet. It is of course one that is not in any way caused by any of the stakeholders in the European natural products industry.”​ 

He told us this was a criminal issue – not one of industry standards or adequate legislation.  

“The players who supply such products are essentially pirate operators who exploit vulnerability of individuals keen to lose weight and use the largely unregulated Internet as their portal. They unfortunately risk tarnishing the reputation of the vast majority of operators who maintain rigorous quality control standards.”

He said studies such as this may spark the international effort needed to track down these manufacturers in producing countries and prosecute culprits.  

Dr Luca Bucchini, managing director of Italian firm Hylobates Consulting, echoed the view this was an issue with a rogue minority. 

"These problems continue to come up for two reasons. First, a minority of manufacturers and brands look for efficacy, without too many questions asked; ingredient suppliers are keen to find a solution which works, meaning often adulteration or substitution with a pharmaceutical principle. Second, a minority of ingredient suppliers and manufacturers do not have quality control programs in place, and contamination - at low levels - creeps in along the contamination."  

The study was funded by the French National Agency for the Safety of Medicines and Health Products (ANSM).


Source: Journal of Pharmaceutical and Biomedical Analysis

Vol 124, pp 34–47,doi:10.1016/j.jpba.2016.02.022

“Proton NMR for detection, identification and quantification of adulterants in 160 herbal food supplements marketed for weight loss”

Authors: R. Hachem, G. Assemat, N. Martins, S. Balayssac, V. Gilard, R. Martino and M. Malet-Martino 

Related topics Research Adulteration Botanicals

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