Fish oil is essentially a collection of fatty acids, many of which are very important for your overall health. A common misconception is that fatty acids (fats) are bad for you. Many of the fatty acids in fish oil are critical for cell membrane composition (so is cholesterol and people say that's bad too). The basic reason to take fish oil is the price. Even if there is little health incentive to take it, the fact that it is only <$10 for 180 caplets (take 2 per day) makes it worthwhile. I would and do pay $10 every 3 months with the hopes that the fish oil I do take is doing something beneficial for me.