Oral contraceptives may alleviate painful periods for some women, suggests a 30-year study.
Estimates suggest more than half of women have suffered from the condition, called dysmenorrhoea, at some point.
The Scandinavian study, reported in the journal Human Reproduction, found women on the pill reported slightly less severe period pains.
Oral contraceptives are not currently officially licensed for this purpose.
The researchers, from Sahlgrenska Academy at Gothenburg University, followed groups of hundreds of 19-year-olds, recruiting some in 1981, some in 1991, and the rest in 2001.
Five years after an initial health questionnaire, the women were contacted again to see if anything had changed.