There can be some benefit to taking a supplement but only if it's is just omega 3. Many companies will sell a combination pill that includes omega 6 and omega 9. In small doses these omegas are helpful, but most of use get more then enough of them from foods. Too much of these omegas can actually have a negative impact on the good cholesterol in your body. Also, in these combination pills, the omega 3 dose tends to be lower.
So if you are struggling to get Omega 3 from food, consider a supplement, but look for just omega 3. If you are unsure which brand to purchase, speak to your doctor or local dietitian for further guidance.