I recently read a research paper that suggested males and females respond differently to DHA and EPA supplementation, at least in terms of their risks for heart attack and stroke.
Specifically, men respond better (i.e. have more beneficial changes in platelet aggregation) to EPA while women respond better to DHA. The researchers speculated that different interactions between sex hormones and the omega-3 fats are at least partly responsible for these effects.
This is very interesting data, and if it pans out there may be good reasons to formulate gender-specific omega-3 products.