Chinese Olympic officials have advised national athletes not to take traditional remedies because some contain banned substances such as herbal ephedrine, a stimulant.

中国奥运官员已建议中国运动员不要服用传统中药，因为某些中药含有违禁的兴奋剂类物质，如麻黄。

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Did Armstrong take banned substances?

NPR: Armstrong Admits Doping: 'I'm A Flawed Character'

The National Amateur Body Builders Association (NABBA) said it had not heard of anyone buying banned substances over the internet, but would take a hard line with any members who did.

BBC: Internet steroid sales warning

Dr Gerry McCann, a lecturer in sports medicine at the Centre for Exercise Science and Medicine at Glasgow University, said the list of banned substances was so comprehensive that it was highly unlikely that an athlete could take a legal substance, but register a positive result in a doping test.

BBC: Doping: Banned substances