Hello. I am not sure if I noticed a difference in one over the other (for healthy hair & nails) but both are quite beneficial to your overall health. Beware of the mercury content in your fish oil capsules, the oil is concentrated so it is possible to have a high concentration of mercury as well. Ground Flax seed is very good if you want to supplement with a combination of both, I used to add it to my cereal and even works well in baked goods (like a favorite muffin mix). It has a pleasant nutty flavor, it contains fiber, and can really be added to any food (even a tomato sauce) if you are trying to help sneak some healthy food into a spouse's or partner's diet (or your own). Just be sure to store it in the freezer as it is perishable.