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Dying to be slim Alarm sounded over illegal diet pills

Packs of slimming aids that were found to contain dangerous, undeclared ingredients during Swissmedic laboratory analysis


Swiss experts have stepped up their warnings about slimming aids bought over the internet. Some marketed as a “coffee” product have shown a high level of the potentially fatal substance sibutramine, banned in Switzerland since 2010.

The comments come amid a crackdownexternal link, announced on June 18, of 600 packages of illegal drug imports to Switzerland, part of an international operation, which netted 56 packets containing harmful medicines, including slimming preparations.

Anna*, an IT specialist, was desperate to lose weight after having children. As various diets had failed, she turned to the internet.

“I started with plant-based substances like asparagus capsules, pineapple or green tea pills, and artichoke juice. This of course didn’t work and simply cost a lot of money,” she told

She moved to fat and carbohydrate blockers, but without success. So she tried pills containing sibutramine, having heard that they stopped you thinking about food. It was easy to order them online. A packet of 30 pills cost around CHF100 ($108) per month.

“Not too long after I had palpitations and felt lightheaded the whole time, this affected my concentration which was not good for my work,” she said. Worried, especially after researching the substance further, she threw the capsules away.

She has not touched sibutramine since and now maintains her weight - even if it not as low as she would like – through cutting out alcohol during the week and exercise.


The Swiss Agency for Therapeutic Products, Swissmedicexternal link has long been aware of the problem of illegal diet pills bought online. In May, it released an analysisexternal link of 61 illegally imported slimming aids, the results of which it called “perturbing”.

“More than three quarters of the tested products had undeclared substances and more than half had the substance sibutramine, which in 2010 was taken off the market worldwide because of its health risks – it causes cardiovascular problems. In some samples, they found three times the formerly allowed dose, which is dangerous,” Peter Balzli, head of communications at Swissmedic, told

“And something else to note: two thirds of products said they were ‘natural’ or ‘herbal’, many looked like harmless instant drinks, but in reality almost all contained dangerous substances.”

It was a coffee product that contained the extremely high levels of sibutramine (45mg). This kind of packaging increases the risk that people do not know what they are taking, said Balzli.

Sibutramine risk

Sibutramine used to be prescribed as a weight loss aid as it suppresses appetite and induces a feeling of satiety, but studies later showed an increased risk of cardiovascular events, such as a heart attack and stroke, which led to it being taken off the market.

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But it is still reaching Switzerland by the back door. “Some of the pills will be seized by Swiss Customs, but most will be delivered to their recipient,” said Balzli.

The products analysed by Swissmedic mostly came from Asia. “But occasionally in Switzerland there is a lab which produces illegal medications or doping,” said Balzli.

A search on the internet turns up all manner of diet aids, promising like one popular Chinese product, that you can lose 20 kilograms in just ten weeks – without any medical prescription.

No quick fix

Stefan Weiler, of the Department of Clinical Pharmacology and Toxicologyexternal link at the University Hospital of Zurich, said that sibutramine used to be prescribed as part of an overall concept for weight loss including counselling, exercise and medical support, not just as a quick fix.

Swissmedic is aware of reports from other countries of people being hospitalised after taking sibutramine.

Weiler’s department is also one of six regional pharmacovigilance (drug safety) centresexternal link in Switzerland, which records adverse effects and events from licenced drugs.

The centre has come across reactions to sibutramine, such as palpitations, nausea and breathing problems, as reported to them by health care professionals, he said.

DNP danger

Swissmedic’s testing also uncovered other undeclared active ingredients like painkillers (paracetamol) and antidepressants (fluoxetine).

But it did not find any dinitrophenol (DNP), currently subject to a global alertexternal link by Interpol. This follows cases in which weight loss pills thought to contain the substance left a man in France critically ill and killed a young womanexternal link in Britain.

Balzli said DNP, which has fat burning properties, was known in Switzerland and there have been products found, if not that often, in the bodybuilder and fitness centre milieu.

Selling DNP as a medicine is a crime, said Balzli. Taking such pills is not, but you will most probably ruin your health, he warned.

DNP has been around since the early 1900s, but was first banned in 1938 and then again in 2003. It is still widely available on the internet and has been commercially used as an insecticide, herbicide or dye substance, added Weiler.

“It also has a lot of acute effects, if you have an increased dose you can have fever, fast breathing, sweating, a headache, or feeling of malaise but also severe reactions like seizures, coma, fluids in the lung or arrhythmia of the heart have been described. There can be organ failure, liver or kidney, so it can also be fatal,” he said. 

Clamping down

Balzli says it is difficult to tell just how many illegal diet products are coming into Switzerland. Swissmedic statistics for 2014 external linkshowed 1,225 seizures, of which 10% were found to be slimming products.

Interestingly, the June drug haul was smaller than last year, which Swissmedic attributes to a processing cost of CHF300 ($327) for those caught importing the drugs, as well as targeted awareness campaigns.

In any case, clamping down on these products is not easy, even if Swiss Customs is very active in this area.

Swissmedic also works with foreign authorities, informing, for example, Indian officials if packages are intercepted from that country, so they can go after the source of the illegal pills.

*Name withheld 

Swissmedic’s analysis in detail

41 products claimed to be "natural" or "herbal". In fact, 35 of these products contained dangerous chemical ingredients.

Ten products were coffee-based drinks. Eight these contained synthetic ingredients. One coffee bag contained 45mg of sibutramine, equivalent to three times the (former) maximum daily dosage.

Four products were bags containing fruit juice powder, three of which contained undeclared harmful ingredients.

Four products were capsules containing sibutramine as a declared ingredient. One of these contained the stated quantity, two an incorrect quantity, and one product did not even contain any active ingredient.

Other undeclared active ingredients found in products included painkillers (paracetamol), anti-inflammatories (diclofenac) and antidepressants (fluoxetine), none of which were declared.

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