In this paper I hypothesize that a woman through her vagina absorbs sufficient quantities of the prostaglandins from her partner's semen, to affect her mood. The vagina appears to have an active transport mechanism which readily absorbs the hormones found in seminal plasma. The seminal secretions include estrogens, F.S.H., LH, testosterone, and at least 13 prostaglandins. Prostaglandins have a modulating effect on neurotransmitters. Evening Primrose Oil (E.P.O., Efamol) may improve depressed mood by facilitating the production of prostaglandins. I have described a depressed, child abusing mother who was possibly getting insufficient exogenous prostaglandins post-partum to maintain her pre-partum mood state because she was avoiding intercourse with her husband. When her mood improved on E.P.O., she began enjoying her husband and her child. If these observations and deductions are correct, regular amounts of seminal plasma may be important in maintaining a woman's affective health and E.P.O. may be useful in treating depressed abusing mothers.