This is completely subjective from my own experience, but it seems whenever I've tried taking fish oil supplements before, on more than one occasion I've felt kind of depressed and lethargic after a few days of taking them so I stop, then everything's back to normal. It's happened enough to suspect a pattern.<p>I'll stick with natural sources for these oils. Eggs, walnuts, etc. no problem, I eat lots of foods with omega-3s. Maybe there is something unnatural about swallowing a big concentrated dose of the stuff?<p>I don't really care to repeat the experiment to find out...