When healthy young men take a specific form of omega-3 fatty acids bound to medium-chain triglycerides for eight weeks, their blood shows a higher ratio of EPA to arachidonic acid than when they take the same fatty acids in a simple mixed form.

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.

Taking EPA in either structured triglyceride or mixed form raises the ratio of EPA to AA in the blood of healthy young men, and the effect depends on how much EPA is consumed, not how it is chemically arranged.

In healthy young men, taking EPA in a structured triglyceride form may result in a slightly higher level of EPA in the blood compared to a simple mixture of the same components, but the difference was not large enough to be considered statistically certain.

Taking EPA and DHA supplements in structured triglyceride or mixed forms for eight weeks does not make healthy young men stronger or less fatigued during weight training, even though their blood levels of EPA relative to AA increase.

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.