If you're a healthy young adult, taking a high-purity fish oil supplement might help your body absorb more of the good omega-3s (like EPA and DHA) into your red blood cells compared to a lower-purity...

Taking high-quality fish oil pills with more of a certain form (called re-esterified triglycerides) leads to higher levels of a healthy fat called DPA in your blood cells after four months, compared to lower-quality ones.

If you're a healthy young adult, taking a high-purity fish oil supplement might improve your blood fat levels faster than a lower-purity one — and you could see changes in just four weeks.

Fish oil supplements with over 95% re-esterified triglycerides (a type of fat form) seem to get more omega-3s into your blood cells after 16 weeks than those with less than 70%, so this might be a good sign of a better-quality supplement.

People with more of the good omega-3 fats (EPA and DHA) in their red blood cells tend to have less heart disease and do better over time if they already have heart problems.

Taking fish oil supplements with EPA and DHA over time makes the membranes of your red blood cells more filled with these types of fats, making them more flexible but also more prone to damage from oxidation.