The included studies were small and of variable quality.
Premenstrual syndrome is associated with a mixture of emotional, somatic and behavioural symptoms.
It is thought to result from disruption to the normal levels of certain fatty acids in the body. The latter is thought to be helpful in restoring the body's natural balance of fatty acids. Report No. 65, December 1996. Evening primrose oil for cyclical mastalgia. Research and Development Directorate.