Is flax seed safe for long-term use?

It appears that flax seed is somewhat safe, but the occasional patient has been reported to develop an allergic reaction. One should only consume the flax seed which have been prepared and sold in health food stores. Unripe flaxseeds or raw seeds are poisonous and can increase levels of cyanide. There are other reports that flax seeds can change mood, increases bowel movements, and even alter the menstrual cycles.  People taking pharmaceutical medications should be warned that flax seed does interact with blood thinning medications