Hmm
How are you taking the flax oil? I mean Flax oil is prefered buy Olive oil can be used. If you mix it in with your shakes it isnt bad at all. Do you keep it refrigerated or out on the counter, it could be rancid if left un refridgerated. This is my shake I use unflavored whey, so I put 3 scoops of whey, 1 Tablespoon of flax, some sugar free chocoloate syrup and mix. It dont taste good but it isnt bad. Try slamming it down, This isnt desert or a Filet Migon you arent supposed to savor it or be like damn thats a good shake, Down it, then drink a glass of water, wipe off your mouth so you dont get the milk mustache and CHill.
Good Luck