I have not checked into GNS flax seed oil, so I cannot give you a direct answer. However, here are some things to look for:
1. Is it fresh? Check the expiration date. If they don't have one, I would be cautious and probably pass it by. I would not buy any flax seed oil that is older than six months.
2. Is it kept refrigerated in the store? If it is not, forget it.
3. How is it packaged? Are the bottles light-proof? In my opinion, the gel-caps are of little use.