Fish oil in and of itself is not going to cause hair loss. (Sigh!) Why WOULD it? It's a proven anti-inflammatory. And there'd have to be something IN its composition -- from the prespective of chemistry -- to cause you to lose hair. What would that BE? Just make sure that your fish oil is molecularly distilled. You don't want it containing mercury, etc. And yes, it's wise to know how supplements and medicines can affect each other and to space them apart if need be. And fish oil may slow down absorption of some vitamins/minerals, but that's not going to be enough to cause bald spots! Besides, you may be eating something else -- e.g., a lot of citrus or enzymes -- that makes your absorption of vitamins/minerals quicker overall. This is really subtle stuff, and I believe it's a red herring (pardon the pun) when it comes to hair loss: that is, focusing on "dietary nuances" merely deflects attention away from the more likely causes of hair loss (hormonal disorders, immunological disorders, genetics, etc.). If fish oil caused hair loss, then all of Canada's coastal aboriginal peoples (especially in the far north) would be balding. Do you realize how much fish and fish oil some people eat on a regular basis? Look for reputable scholarly sources, ladies -- don't believe everything you hear and read. What's it going to be next: olive oil causes hair loss? Sunflower oil? Butter?