I personally think that flax is a poor choice, so I'll go into a little more detail and explain why:
When you start looking at what happens to flax in the body you'll notice that flaxseed has very poor
EPA conversion of around 10% and ZERO
conversion to DHA (DHA is an extremely important omega 3 fatty acid with benefits to the eyes, brain, heart and nervous system):
Flax contains omega 6 which is pro-inflammatory, basically meaning that it increases the production of inflammatory chemicals known as eicosanoids, Also worth bearing in mind is that a lot of people, including vegans are significantly deficient in Omega 3's, and the ingestion of Omega 6 further reduces omega 3 blood levels. Just to make matters even worse, women tend to be more efficient at converting it than men are
So I'd go for hemp, chia and/or a vegan omega 3 oil (microalgae oil is a great choice due to it being high strength). The one I use has 833mg omega 3 per capsule and provides 200mg DHA/100mg EPA.