What's the difference between the omega 3 fatty acids found in flax seed oil and fish oil?

Different fats: The fatty acid most commonly found in flax-seed oil is α-linolenic acid (ala, 18 carbons and 3 double bonds). In fish oil, they are eicosapentaenoic acid (epa, 20 carbons and 5 double bonds), docosahexaenoic acid (dha, 22 carbons and 6 double bonds). Ala converts to epa and dha, but in limited amounts. Best to get your epa and dha from actual wild salmon and your ala from flax.