Can these pills kill?
Hong Kong health experts want tighter monitoring of ephedra - a natural stimulant found in weight-loss tablets and slimming teas - after America announced earlier this month that it would ban the sale of the substance.
The US Food and Drug Administration took action after a review of 16,000 reports of adverse reactions that included heart attack, stroke and sudden death.
Ephedrine, the active ingredient in ephedra - a plant also known as ma huang - can increase heart rate, raise blood pressure and speed up brain activity. It's been used in China for centuries to treat asthma and other respiratory problems. But it has also been promoted for its ability to enhance sports performance and increase energy, even though there is little evidence to support these claims.
Hong Kong-based nutritionist Gabrielle Tuscher says she's concerned about the widespread use of ephedra in Hong Kong, particularly in slimming teas and weight-loss tablets, and wants tighter controls.
'When I was living In New York, a lot of people were taking ephedra-based products to lose weight. Then links were made to strokes and heart attacks. And I'm not talking about people in the over-40 age group - these were fit people in their 20s.
'I'm glad to hear that stricter rules are being followed in the US,' she says. 'But Hong Kong needs to follow suit. It needs to be regulated by a government agency, like what is happening now with stricter monitoring of Chinese medicines.'
Tuscher says people often ignored the recommended dosage, believing the more they took, the more weight they'd lose. 'If a box of diet tablets recommends one tablet a day, some people take four a day thinking, they'll lose more weight. It's stupid logic that could have fatal consequences.'
Tuscher says Hong Kong has yet to conduct studies into ephedra-related deaths, but says she has seen patients with damaged heart valves, and has traced it back to the ephedra in their diet tablets.
Jennifer Walker, a naturopath at Zama in Central, says western herbalists, like Chinese herbalists, use the herb only to treat breathing ailments, although she says it is being used less often in the west.
'In the right hands - that is, when used by a trained Chinese herbalist - this is a valuable herb for bronchial conditions,' she says.
'However, there has been misuse of this herb in a variety of over-the-counter preparations, mainly from the US, promising weight loss, increased energy and so forth.
'Because of people self-administering and not understanding the possible adverse effects - and that it is contra-indicated for those with heart conditions, high blood pressure and hyperthyroidism - there have been some serious repercussions.
'Unfortunately, the blame has been placed on ephedra itself, rather than the fact that it hasn't been taken correctly or for the right reasons.'