Melatonin in herbs hold answer to jet lag

Doctors have identified a new herbal remedy for jet lag. Feverfew, the plant used to treat migraine, has been shown to contain substantial amounts of melatonin which is known to help regulate the body's internal clock.

Canadian researchers who analysed leaf samples of feverfew and two other herbs - St John's Wort used to treat depression, and Huang-qin - found melatonin present in all three. They speculate in the Lancet that the presence of melatonin may partly explain their medicinal effects.

The long term effects of melatonin are unknown and its sale was banned in Britain in 1995, although it is available on prescription. The researchers say their findings demonstrate that herbal remedies may contain powerful agents and emphasises the need for full investigation of the chemicals in them.