Flaxseed oil or Omega 3 fish oil?
First their sources, Omega 3 fish oil comes from marine animals and flaxseed oil is plant-based.
Omega 3 fish oil has 2 main components: EPA and DHA. Combined, they’re great for heart and brain health. Flaxseed is made up of ALA which has to be broken down by our bodies to become EPA and DHA.
The ratios, therefore, are not the same. You’d need to take 6 times the amount of flaxseed oil in order to match the amount of omega 3s.
They both do have their issues, flaxseed should not be heated and it can go rancid. Omega 3 fish oil can be full of toxins depending on the sourcing of the fish.
Overall, I would recommend Omega 3 over flaxseed, but the best scenario is probably to use both to get our bodies the healthy fats they need.