It's a long road to legitimacy. Traditional Chinese medicine, which has been tried and tested on its home turf over three millennia, is working hard to gain mainstream acceptance in the west, where there are stricter regulations and requirements for therapeutic trials.

Based on a range of remedies inherited from Taoist scholars, and also on acupuncture, traditional Chinese medicine is derived from Confucianism. But it would be a mistake to suppose that what is now officially known as TCM has traversed so many centuries unchanged.

"TCM is a political construct dating from the 1950s, following on from the 1949 revolution," says Professor Paul Unschuld of Berlin Medical University, who chairs the International Society for the History of East Asian Science, Technology and Medicine. "It includes selected aspects of historical Chinese medicine, but it is also influenced by the rationale and concepts of modern science."

Despite the slow acceptance, there have been advances. In Europe, where little was known about Chinese practices, TCM gained traction in the 1970s as part of the movement towards alternative therapies. A World Health Organisation congress emphasised the legacy of such medicine in a 2008 declaration, though stressed the need to hasten its modernisation and acceptance.

China, too, has realised the need to integrate and advance, and has been working since 2007 to abandon some outdated methods.

"Many Chinese medicinal herbs are used in south-east Asia, in Singapore and Indonesia, but also Russia and Australia," says Professor Guo De-an, chief scientist at the Shanghai Institute of Materia Medica and a member of the Chinese Academy of Sciences. "But Europe and the United States account for the major part of the global pharmaceutical market."

To gain a foothold in the market for prescription drugs in the US and Europe, manufacturers must comply with the standards set by the agencies tasked with regulating healthcare products. They must satisfy requirements for both pharmacological effectiveness and overall quality.

"There is still no appropriate methodology for assessing the effects of TCM," says Guo. "It is not sufficient to measure blood pressure … the question is how to carry out group studies of individualised treatment."

Robert Verpoorte, the head of the Natural Products laboratory at Leiden University in the Netherlands, advocates a new approach to studying traditional Chinese medicine. "We should base our approach on the effects produced by a medicinal plant on living organisms resulting from the activity of its many components," he says. "This approach is used in systems biology and metabolomics, which studies all the metabolites present in a cell or organism."

Guo sees two ways ahead for medicinal plants used in TCM: "Either they can be authorised, through a simplified procedure, as traditional plant-based treatments; or they may obtain the status of herbal medicinal products for human use as defined by the European Medicines Agency," he says.

The Chinese government has encouraged efforts to obtain US and EU authorisation of TCM-derived drugs for treating heart disease and menopause-related disorders.

"For the time being there is no alternative to western assessment criteria and we must work hard to provide the data required by the US and EU agencies," he says.

As these therapies seek to gain greater recognition, the question of side effects also looms. Chinese advocates have tended to assert that TCM remedies are safe.

But at a recent conference on such treatments in Bologna, one speaker diverged from this position. Defending an approach based on strict clinical trials, Bian Zhao-xiang, the head of the clinical division of the School of Chinese Medicine at Hong Kong Baptist University, said: "We must improve reporting of side effects."

Co-operation between China and the west is developing. "Several major western drug firms have invested in industrial co-operation projects," says Guo.

This article originally appeared in Le Monde