The Therapeutic Goods Administration said it has received a number of reports about so-called “herbal” and “drug-free” weight-loss products being sold online from overseas distributors.
Its principal medical advisor said that many of these products contained unlisted ingredients that could be harmful. Some are not even approved for supply in Australia.
"In Australia, many weight-loss products are considered medicines. We have no control over medicines and supplements purchased from overseas by consumers on the web,” said Tim Greenaway.
Products containing undisclosed pharmaceutical substances were among the “most concerning” nutritional imports found by the TGA.
Through the regulator, Australia has some of the world’s tightest controls over the manufacturing and supply of nutraceuticals both at home and abroad.
Analysis by the TGA has recently identified products containing sibutramine and phenolphthalein, both withdrawn prescription drugs that could heighten the risk of cardiac events or cancer, among dietary shipments to Australia.
"We strongly urge Australians to use extreme caution when considering buying weight-loss medicines online from unknown websites,” Dr Greenaway said.
"People should also be suspicious of wild claims. If a website or product seems too good to be true, it probably is. Make sure you're buying from a legitimate Australian pharmacy."
The natural nutrition industry’s representative body, Complementary Medicines Australia, has reiterated the warning.
“The importance of the ‘online buyer beware’ message cannot be stressed enough and applies to all complementary medicine products,” said Carl Gibson, its chief executive.
“Any products that are medicinal in nature but not listed on the TGA’s Australian Register of Therapeutic Goods may not meet the quality and safety standards expected by Australian consumers.”
Such products may have elevated levels of heavy metals, pesticides or microbial contaminants, which are not screened for in many countries.
“They may also contain low levels of stated herbal active ingredients, the wrong herb entirely, or be adulterated with other unknown ingredients,” Gibson added.