Flaxseed Oil sold as containing Omega 3 fatty acids, is misleading.
High in ALA, it may convert to similar Omega 3 found in fish oils, only you have an active enzyme delta-6-destaurase, allowing for minimal conversion.
A paper I came across a few years ago, mention high population of Mexicans, Welsh and other population have the active delta-6-destaurase, for negligible conversion.