The herbal remedy echinacea is not effective in treating children's colds, researchers have found.
A study compared the treatment with a dummy pill and found no difference in how long the children were ill for.
Over 500 children were studied by doctors at the University of Washington in Seattle.
But herbalists said the study contradicted other research which showed that echinacea was "powerful and effective".The study looked at upper respiratory tract infections in children.
Most children have between six and eight such infections each year, each of which lasts around a week.
Children may be given drugs such as decongestants, antihistamines, or cough suppressants, but there is little evidence that these are effective in those under 12.
Source BBC News